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{\b\fs32\par\pard\qc\li0\tx0\tx20000\~ SH\~(\~1\~)\~\~\~\~\~\~\~\~\~\~\~\~\~USER

COMMANDS\~\~\~\~\~\~\~\~\~\~\~\~SH\~(\~1\~)}

}{\brdrt\brdrsh\par}{\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.NAME} NAME

\~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}sh, rsh \'2d shell,

the standard/restricted command and programming language {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.SYNOPSIS} SYNOPSIS

\~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}{\b sh }[ {\b\'b1 abcefhikmnoprstuvxCD

}] [ {\b\'2d R }file ] [ {\b\'b1 o }option

] .\~.\~. [ {\b\'2d }] [ arg .\~.\~. ] {\b\line rsh

}[ {\b\'b1 abcefhikmnoprstuvxCD }] [ {\b\'2d R

}file ] [ {\b\'b1 o }option ] .\~.\~. [ {\b\'2d

}] [ arg .\~.\~. ] {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.DESCRIPTION} DESCRIPTION

\~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}{\i Sh }is a command and

programming language that executes commands read from a terminal or a file.

{\i Rsh }is a restricted version of the standard command interpreter {\i sh};

it is used to set up login names and execution environments whose capabilities

are more controlled than those of the standard shell. See {\i Invocation

}below for the meaning of arguments to the shell. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Definitions} Definitions.

\~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}A {\i metacharacter }is

one of the following characters: {\b\par\pard\qc\li1120\tx1120\tx20000 ; & ( ) | < > new-line

space tab} \par\pard\qc\li840\tx840\tx20000 A {\i blank }is a {\b tab }or a {\b space}.

An {\i identifier }is a sequence of letters, digits, or underscores starting

with a letter or underscore. Identifiers are used as components of {\i variable

}names. A {\i vname }is a sequence of one or more identifiers separated

by a {\b{\fs26 .}} and optionally preceded by a {\b{\fs26 .}}.

Vnames are used as function and variable names. A {\i word }is a sequence

of {\i characters }from the character set defined by the current locale,

excluding non-quoted {\i metacharacters}. \par\pard\qc\li840\tx840\tx20000 A {\i command }is a sequence

of characters in the syntax of the shell language. The shell reads each

command and carries out the desired action either directly or by invoking

separate utilities. A built-in command is a command that is carried out

by the shell itself without creating a separate process. Some commands are

built-in purely for convenience and are not documented here. Built-ins that

cause side effects in the shell environment and built-ins that are found

before performing a path search (see {\uldb Execution}{\v HTML2RTF.Execution}{\*\comment{\i Execution }}below)

are documented here. For historical reasons, some of these built-ins behave

differently than other built-ins and are called {\i special built-ins}.

{\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Commands} Commands. \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}A

{\i simple-command }is a list of variable assignments (see {\uldb Variable Assignments}{\v HTML2RTF.Variable.Assignments}{\*\comment{\i Variable

Assignments }}below) or a sequence of {\i blank }separated words which

may be preceded by a list of variable assignments (see {\uldb Environment}{\v HTML2RTF.Environment}{\*\comment{\i Environment

}}below). The first word specifies the name of the command to be executed.

Except as specified below, the remaining words are passed as arguments to

the invoked command. The command name is passed as argument 0 (see {\i exec}(2)).

The {\i value }of a simple-command is its exit status; 0-255 if it terminates

normally; 256+{\i signum\~}if it terminates abnormally (the name of

the signal corresponding to the exit status can be obtained via the {\b\'2d l

}option of the {\b kill }built-in utility). \par\pard\qc\li840\tx840\tx20000 A {\i pipeline

}is a sequence of one or more {\i commands }separated by {\b |}.

The standard output of each command but the last is connected by a {\i pipe}(2)

to the standard input of the next command. Each command, except possibly

the last, is run as a separate process; the shell waits for the last command

to terminate. The exit status of a pipeline is the exit status of the last

command. Each pipeline can be preceded by the {\i reserved word }{\b !

}which causes the exit status of the pipeline to become 0 if the exit

status of the last command is non-zero, and 1 if the exit status of the

last command is 0. \par\pard\qc\li840\tx840\tx20000 A {\i list }is a sequence of one or more pipelines

separated by {\b ;}, {\b&}, {\b |&}, {\b&&},

or {\b |\~|}, and optionally terminated by {\b ;},

{\b&}, or {\b |&}. Of these five symbols, {\b ;},

{\b&}, and {\b |& }have equal precedence, which

is lower than that of {\b&& }and {\b |\~|}.

The symbols {\b&& }and {\b |\~| }also have equal

precedence. A semicolon ({\b ;}) causes sequential execution of

the preceding pipeline; an ampersand ({\b&}) causes asynchronous

execution of the preceding pipeline (i.e., the shell does {\i not }wait

for that pipeline to finish). The symbol {\b |& }causes asynchronous

execution of the preceding pipeline with a two-way pipe established to the

parent shell; the standard input and output of the spawned pipeline can

be written to and read from by the parent shell by applying the redirection

operators {\b<& }and {\b>& }with arg {\b p

}to commands and by using {\b\'2d p }option of the built-in

commands {\b read }and {\b print }described later. The

symbol {\b&& }(\~{\b |\~|}\~) causes

the {\i list }following it to be executed only if the preceding pipeline

returns a zero (non-zero) value. One or more new-lines may appear in a {\i list

}instead of a semicolon, to delimit a command. \par\pard\qc\li840\tx840\tx20000 A {\i command }is either

a simple-command or one of the following. Unless otherwise stated, the value

returned by a command is that of the last simple-command executed in the

command. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 for} {\i vname\~}[\~{\b in}

{\i word\~}.\~.\~. \~] {\b ;do}{\i list\~}{\b ;done}

\tab Each time a {\b for }command is executed, {\i vname }is set

to the next {\i word }taken from the {\b in }{\i word }list.

If {\b in}{\i word\~}.\~.\~. is omitted, then the

{\b for }command executes the {\b do} {\i list\~}once

for each positional parameter that is set starting from {\b 1 }(see

{\uldb Parameter Expansion}{\v HTML2RTF.Parameter.Expansion}{\*\comment{\i Parameter Expansion }}below). Execution ends

when there are no more words in the list. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 for ((} [\~{\i expr1\~}\~]

{\b ;} [\~{\i expr2\~}\~] {\b ;} [\~{\i expr3\~}\~]

{\b ))}{\b ;do}{\i list\~}{\b ;done} \tab The

arithmetic expression {\i expr1 }is evaluated first (see {\uldb Arithmetic Evaluation}{\v HTML2RTF.Arithmetic.Evaluation}{\*\comment{\i Arithmetic

Evaluation }}below). The arithmetic expression {\i expr2 }is repeatedly

evaluated until it evaluates to zero and when non-zero, {\i list }is executed

and the arithmetic expression {\i expr3 }evaluated. If any expression is

omitted, then it behaves as if it evaluated to 1. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 select}

{\i vname\~}[\~{\b in} {\i word\~}.\~.\~.

\~] {\b ;do}{\i list\~}{\b ;done} \tab A {\b select

}command prints on standard error (file descriptor 2) the set of {\i word}s,

each preceded by a number. If {\b in}{\i word\~}.\~.\~.

is omitted, then the positional parameters starting from {\b 1 }are

used instead (see {\uldb Parameter Expansion}{\v HTML2RTF.Parameter.Expansion}{\*\comment{\i Parameter Expansion }}below).

The {\fs22{\b PS3 }}prompt is printed and a line is read

from the standard input. If this line consists of the number of one of the

listed {\i word}s, then the value of the variable {\i vname }is set to

the {\i word }corresponding to this number. If this line is empty, the

selection list is printed again. Otherwise the value of the variable {\i vname

}is set to {\i null}. The contents of the line read from standard input

is saved in the variable {\fs22{\b REPLY}. }The {\i list

}is executed for each selection until a {\b break }or {\i end-of-file

}is encountered. If the {\fs22{\b REPLY }}variable is

set to {\i null }by the execution of {\i list}, then the selection list

is printed before displaying the {\fs22{\b PS3 }}prompt

for the next selection. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 case} {\i word\~}{\b in}

[\~[\~{\b (}\~]{\i pattern\~}[\~| {\i pattern\~}\~].\~.\~.{\b )}{\i list\~}{\b ;;}\~].\~.\~.{\b esac}

\tab A {\b case }command executes the {\i list }associated with

the first {\i pattern }that matches {\i word}. The form of the patterns

is the same as that used for file-name generation (see {\uldb File Name Generation}{\v HTML2RTF.File.Name.Generation}{\*\comment{\i File

Name Generation }}below). The {\b ;; }operator causes execution

of {\b case }to terminate. If {\b ;& }is used in place

of {\b ;; }the next subsequent list, if any, is executed. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 if}

{\i list\~}{\b ;then} {\i list\~}[\~{\b elif}

{\i list\~}{\b ;then}{\i list\~}\~].\~.\~.[\~{\b ;else}{\i list\~}\~]{\b ;fi}

\tab The {\i list }following {\b if} is executed and, if it returns

a zero exit status, the {\i list }following the first {\b then }is

executed. Otherwise, the {\i list }following {\b elif} is executed

and, if its value is zero, the {\i list }following the next {\b then

}is executed. Failing each successive {\b elif }{\i list\~},

the {\b else }{\i list }is executed. If the {\b if }{\i list

}has non-zero exit status and there is no {\b else }{\i list},

then the {\b if }command returns a zero exit status. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 while}

{\i list\~}{\b ;do} {\i list\~}{\b ;done} \tab{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 until}

{\i list\~}{\b ;do} {\i list\~}{\b ;done} \tab A

{\b while }command repeatedly executes the {\b while }{\i list

}and, if the exit status of the last command in the list is zero, executes

the {\b do }{\i list}; otherwise the loop terminates. If no commands

in the {\b do }{\i list }are executed, then the {\b while }command

returns a zero exit status; {\b until }may be used in place of

{\b while }to negate the loop termination test. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 ((}{\i expression\~}{\b ))}

\tab The {\i expression }is evaluated using the rules for arithmetic evaluation

described below. If the value of the arithmetic expression is non-zero,

the exit status is 0, otherwise the exit status is 1. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 (}{\i list\~}{\b )}

\tab Execute {\i list }in a separate environment. Note, that if two adjacent

open parentheses are needed for nesting, a space must be inserted to avoid

evaluation as an arithmetic command as described above. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\{ }{\i list\~}{\b ;\}}

\tab{\i list }is simply executed. Note that unlike the metacharacters {\b (

}and {\b )}, {\b\{ }and {\b\} }are {\i reserved

word}s and must occur at the beginning of a line or after a {\b ; }in

order to be recognized. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 [[}{\i expression \~}{\b ]]}

\tab Evaluates {\i expression }and returns a zero exit status when {\i expression

}is true. See {\i Conditional Expressions }below, for a description of

{\i expression}. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 function} {\i varname\~}{\b\{}

{\i list\~}{\b ;\}} \tab{\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 varname\~}{\b () \{}

{\i list\~}{\b ;\}} \tab Define a function which is referenced

by {\i varname}. A function whose {\i varname }contains a {\b{\fs26 .}

}is called a discipline function and the portion of the {\i varname

}preceding the last {\b{\fs26 .} }must refer to an existing

variable. The body of the function is the {\i list }of commands between

{\b\{ }and {\b\}}. A function defined with the {\b function}

{\i varname\~}syntax can also be used as an argument to the {\b .}

special built-in command to get the equivalent behavior as if the {\i varname\~}{\b ()}

syntax were used to define it. (See {\i Functions }below.) {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 time}

[\~{\i pipeline\~}\~] \tab If {\i pipeline\~}is omitted

the user and system time for the current shell and completed child processes

is printed on standard error. Otherwise, {\i pipeline }is executed and

the elapsed time as well as the user and system time are printed on standard

error. \par\pard\qc\li840\tx840\tx20000 The following reserved words are recognized as reserved only

when they are the first word of a command and are not quoted: {\b\par\pard\qc\li1120\tx1120\tx20000 if

then else elif fi case esac for while until do done \{ \} function select

time [[ ]] ! }{\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Variable.Assignments} Variable

\~Assignments. \~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}One or more

variable assignments can start a simple command or can be arguments to the

{\b typeset}, {\b export}, or {\b readonly }special

built-in commands. The syntax for an {\i assignment\~}is of the form:

{\i\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 varname\~}{\b =}{\i word\~}\tab{\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 varname\~}{\b [}{\i word\~}{\b ]}={\b}{\i word\~}{\b\tab}No

space is permitted between {\i varname\~}and the {\b =} or

between {\b =} and {\i word\~}. {\i\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 varname\~}{\b =(}{\i assign_list\~}{\b )}

\tab No space is permitted between {\i varname\~}and the {\b =}.

An {\i assign_list\~}can be one of the following: {\i\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 word\~}...

\tab Indexed array assignment. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 [}{\i word\~}{\b ]=}{\i word\~}.\~.\~.

\tab Associative array assignment. {\i\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 assignment\~}.\~.\~.

\tab Nested variable assignment. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 typeset} [\~{\i options}\~]

{\i assignment\~}.\~.\~. \tab Nested variable assignment. Multiple

assignments can be specified by separating each of them with a {\b ;}.

{\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Comments} Comments. \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}A

word beginning with {\b # }causes that word and all the following

characters up to a new-line to be ignored. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Aliasing} Aliasing.

\~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}The first word of each

command is replaced by the text of an {\b alias }if an {\b alias

}for this word has been defined. An {\b alias }name consists

of any number of characters excluding metacharacters, quoting characters,

file expansion characters, parameter expansion and command substitution

characters, and {\b =}. The replacement string can contain any

valid shell script including the metacharacters listed above. The first

word of each command in the replaced text, other than any that are in the

process of being replaced, will be tested for aliases. If the last character

of the alias value is a {\i blank }then the word following the alias will

also be checked for alias substitution. Aliases can be used to redefine

built-in commands but cannot be used to redefine the reserved words listed

above. Aliases can be created and listed with the {\b alias }command

and can be removed with the {\b unalias }command. {\i\par\pard\qc\li840\tx840\tx20000 Aliasing

}is performed when scripts are read, not while they are executed. Therefore,

for an alias to take effect, the {\b alias }definition command

has to be executed before the command which references the alias is read.

\par\pard\qc\li840\tx840\tx20000 The following aliases are compiled into the shell but can be unset or

redefined: {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 autoload='typeset \'2dfu' }\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 command='command

' }\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 fc=hist }\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 float='typeset \'2dE'

}\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 functions='typeset \'2df' }\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 hash='alias

\'2dt \'2d\~\'2d' }\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 history='hist \'2dl'

}\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 integer='typeset \'2di' }\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 nameref='typeset

\'2dn' }\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 nohup='nohup ' }\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 r='hist \'2ds'

}\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 redirect='command exec' }\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 stop='kill \'2ds

{\fs22 STOP}' }\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 suspend='kill \'2ds {\fs22 STOP}

$$' }\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 times='\{ \{ time;\} 2>&1;\}' }\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 type='whence

\'2dv' }\tab{\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Tilde.Substitution} Tilde

\~Substitution. \~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}After alias

substitution is performed, each word is checked to see if it begins with

an unquoted {\b ~}. For tilde substitution, {\i word }also refers

to the {\i word }portion of parameter expansion (see {\uldb Parameter Expansion}{\v HTML2RTF.Parameter.Expansion}{\*\comment{\i Parameter

Expansion }}below). If it does, then the word up to a {\b / }is

checked to see if it matches a user name in the password database (often

the {\b /etc/passwd }file). If a match is found, the {\b ~ }and

the matched login name are replaced by the login directory of the matched

user. If no match is found, the original text is left unchanged. A {\b ~

}by itself, or in front of a {\b /}, is replaced by {\fs22{\b $HOME}.

}A {\b ~ }followed by a {\b + }or {\b\'2d }is

replaced by the value of {\b{\fs22 $PWD }}and {\b{\fs22 $OLDPWD

}}respectively. \par\pard\qc\li840\tx840\tx20000 In addition, when expanding a {\i variable assignment},

{\i tilde }substitution is attempted when the value of the assignment begins

with a {\b ~}, and when a {\b ~ }appears after a {\b :}.

The {\b : }also terminates a {\b ~ }login name. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Command.Substitution} Command

\~Substitution. \~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}The standard

output from a command enclosed in parentheses preceded by a dollar sign

( {\b $(\~) }) or a pair of grave accents (\~{\b{\fs26 `}\~{\fs26 `}}\~)

may be used as part or all of a word; trailing new-lines are removed. In

the second (obsolete) form, the string between the quotes is processed for

special quoting characters before the command is executed (see {\uldb Quoting}{\v HTML2RTF.Quoting}{\*\comment{\i Quoting

}}below). The command substitution \~{\b $(\~cat file\~)}\~can

be replaced by the equivalent but faster \~{\b $(\~<file\~)}\~.

{\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Arithmetic.Substitution} Arithmetic \~Substitution.

\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}An arithmetic expression enclosed

in double parentheses preceded by a dollar sign ( {\b $((\~)) })

is replaced by the value of the arithmetic expression within the double

parentheses. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Process.Substitution} Process \~Substitution.

\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}This feature is only available

on versions of the UNIX operating system that support the {\b /dev/fd

}directory for naming open files. Each command argument of the form

{\b< (}{\i list\~}{\b )} or {\b> (}{\i list\~}{\b )}

will run process {\i list }asynchronously connected to some file in {\b /dev/fd}.

The name of this file will become the argument to the command. If the form

with {\b> }is selected then writing on this file will provide

input for {\i list}. If {\b< }is used, then the file passed

as an argument will contain the output of the {\i list }process. For example,

{\b\par\pard\qc\li1120\tx1120\tx20000 paste <(cut \'2df1} {\i file1}{\b ) <(cut

\'2df3} {\i file2}{\b ) | tee >(}{\i process1}{\b )

>(}{\i process2}{\b )}{\i }{\i\par\pard\qc\li1120\tx1120\tx20000 cuts }fields 1 and

3 from the files {\i file1 }and {\i file2 }respectively, {\i pastes }the

results together, and sends it to the processes {\i process1 }and {\i process2},

as well as putting it onto the standard output. Note that the file, which

is passed as an argument to the command, is a UNIX {\i pipe}(2) so programs

that expect to {\i lseek}(2) on the file will not work. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Parameter.Expansion} Parameter

\~Expansion. \~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}A {\i parameter

}is a {\i variable}, one or more digits, or any of the characters {\b *},

{\b @}, {\b #}, {\b ?}, {\b\'2d},

{\b $}, and {\b !\~}. A {\i variable }is denoted

by a {\i vname}. To create a variable whose {\i vname }contains a {\b{\fs26 .}},

a variable whose {\i vname }consists of everything before the last {\b{\fs26 .}}

must already exist. A {\i variable }has a {\i value }and zero or more

{\i attributes}. {\i Variables }can be assigned {\i values }and {\i attributes

}by using the {\b typeset }special built-in command. The attributes

supported by the shell are described later with the {\b typeset }special

built-in command. Exported variables pass values and attributes to the environment.

\par\pard\qc\li840\tx840\tx20000 The shell supports both indexed and associative arrays. An element of

an array variable is referenced by a {\i subscript}. A {\i subscript }for

an indexed array is denoted by an {\i arithmetic expression }(see {\uldb Arithmetic Evaluation}{\v HTML2RTF.Arithmetic.Evaluation}{\*\comment{\i Arithmetic

Evaluation }}below) between a {\b [ }and a {\b ]}.

To assign values to an indexed array, use {\b set \'2dA} {\i vname}

{\i value} .\~.\~. . The value of all subscripts must be in the

range of 0 through 4095. Indexed arrays need not be declared. Any reference

to a variable with a valid subscript is legal and an array will be created

if necessary. \par\pard\qc\li840\tx840\tx20000 An associative array is created with the {\b\'2d A

}option to {\b typeset. }A {\i subscript }for an associative

array is denoted by a string enclosed between {\b [ }and {\b ]}.

\par\pard\qc\li840\tx840\tx20000 Referencing any array without a subscript is equivalent to referencing

the array with subscript 0. \par\pard\qc\li840\tx840\tx20000 The {\i value }of a {\i variable }may be

assigned by writing: {\i\par\pard\qc\li1120\tx1120\tx20000 vname}{\b =}{\i value\~\~}[\~{\i vname}{\b =}{\i value

}\~] .\~.\~. \par\pard\qc\li840\tx840\tx20000 or {\i\line vname}{\b [}{\i subscript}{\b ]=}{\i value\~\~}[\~{\i vname}{\b [}{\i subscript}{\b ]=}{\i value

}\~] .\~.\~. \par\pard\qc\li840\tx840\tx20000 Note that no space is allowed before or

after the {\b =}. \par\pard\qc\li840\tx840\tx20000 A {\i nameref }is a variable that is a reference

to another variable. A nameref is created with the {\b\'2d n }attribute

of {\b typeset}. The value of the variable at the time of the {\b typeset

}command becomes the variable that will be referenced whenever the

nameref variable is used. The name of a nameref cannot contain a {\b{\fs26 .}}.

When a variable or function name contains a {\b{\fs26 .}},

and the portion of the name up to the first {\b{\fs26 .}}

matches the name of a nameref, the variable referred to is obtained by replacing

the nameref portion with the name of the variable referenced by the nameref.

A nameref provides a convenient way to refer to the variable inside a function

whose name is passed as an argument to a function. For example, if the name

of a variable is passed as the first argument to a function, the command

{\b\line typeset \'2dn var=$1} \line inside the function

causes references and assignments to {\b var }to be references

and assignments to the variable whose name has been passed to the function.

\par\pard\qc\li840\tx840\tx20000 If either of the floating point attributes, {\b\'2d E}, or

{\b\'2d F}, or the integer attribute, {\b\'2d i},

is set for {\i vname}, then the {\i value }is subject to arithmetic evaluation

as described below. \par\pard\qc\li840\tx840\tx20000 Positional parameters, parameters denoted by a number,

may be assigned values with the {\b set }special built-in command.

Parameter {\b $0 }is set from argument zero when the shell is invoked.

\par\pard\qc\li840\tx840\tx20000 The character {\b $ }is used to introduce substitutable {\i parameters}.

{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b\}} \tab The

shell reads all the characters from {\b $\{ }to the matching {\b\}

}as part of the same word even if it contains braces or metacharacters.

The value, if any, of the parameter is substituted. The braces are required

when {\i parameter }is followed by a letter, digit, or underscore that

is not to be interpreted as part of its name, when the variable name contains

a {\b{\fs26 .}}, or when a variable is subscripted. If

{\i parameter }is one or more digits then it is a positional parameter.

A positional parameter of more than one digit must be enclosed in braces.

If {\i parameter }is {\b * }or {\b @}, then all the positional

parameters, starting with {\b $1}, are substituted (separated by

a field separator character). If an array {\i vname }with subscript {\b *

}or {\b @ }is used, then the value for each of the elements

is substituted, separated by the first character of the value of {\fs22{\b IFS}.

}{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{#}{\i parameter\~}{\b\}} \tab If {\i parameter

}is {\b * }or {\b @}, the number of positional parameters

is substituted. Otherwise, the length of the value of the {\i parameter }is

substituted. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{#}{\i vname}{\b [*]\}} \tab{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{#}{\i vname}{\b [@]\}}

\tab The number of elements in the array {\i vname }is substituted. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{!}{\i vname\~}{\b\}}

\tab Expands to the name of the variable referred to by {\i vname}. This

will be {\i vname }except when {\i vname }is a name reference. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{!}{\i vname\~}{\b [}{\i subscript\~}{\b ]\}}{\i

\tab}Expands to name of the subscript unless {\i subscript }is {\b *

}or {\b @}. When {\i subscript }is {\b *}, the

list of array subscripts for {\i vname\~}is generated. For a variable

that is not an array, the value is 0 if the variable is set. Otherwise it

is null. When {\i subscript }is {\b @}, same as above, except

that when used in double quotes, each array subscript yields a separate

argument. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{!}{\i prefix\~}{\b *\}} \tab Expands

to the names of the variables whose names begin with {\i prefix}. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b :\'2d}{\i word\~}{\b\}}

\tab If {\i parameter }is set and is non-null then substitute its value;

otherwise substitute {\i word}. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b :=}{\i word\~}{\b\}}

\tab If {\i parameter }is not set or is null then set it to {\i word}; the

value of the parameter is then substituted. Positional parameters may not

be assigned to in this way. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b :?}{\i word\~}{\b\}}

\tab If {\i parameter }is set and is non-null then substitute its value;

otherwise, print {\i word }and exit from the shell (if not interactive).

If {\i word }is omitted then a standard message is printed. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b :+}{\i word\~}{\b\}}

\tab If {\i parameter }is set and is non-null then substitute {\i word};

otherwise substitute nothing. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b :}{\i offset\~}{\b :}{\i length\~}{\b\}}

\tab{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b :}{\i offset\~}{\b\}}

\tab Expands to the portion of the value of {\i parameter }starting at the

character (counting from {\b 0\~}) determined by expanding

{\i offset }as an arithmetic expression and consisting of the number of

characters determined by the arithmetic expression defined by {\i length.

}In the second form, the remainder of the value is used. If {\i parameter

}is {\b * }or {\b @}, or is an array name indexed by

{\b * }or {\b @}, then {\i offset }and {\i length }refer

to the array index and number of elements respectively. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b #}{\i pattern\~}{\b\}}

\tab{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b ##}{\i pattern\~}{\b\}}

\tab If the shell {\i pattern }matches the beginning of the value of {\i parameter},

then the value of this expansion is the value of the {\i parameter }with

the matched portion deleted; otherwise the value of this {\i parameter }is

substituted. In the first form the smallest matching pattern is deleted

and in the second form the largest matching pattern is deleted. When {\i parameter

}is {\b @}, {\b *}, or an array variable with subscript

{\b @ }or {\b *}, the substring operation is applied to

each element in turn. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b %}{\i pattern\~}{\b\}}

\tab{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b %%}{\i pattern\~}{\b\}}

\tab If the shell {\i pattern }matches the end of the value of {\i parameter},

then the value of this expansion is the value of the {\i parameter }with

the matched part deleted; otherwise substitute the value of {\i parameter}.

In the first form the smallest matching pattern is deleted and in the second

form the largest matching pattern is deleted. When {\i parameter }is {\b @},

{\b *}, or an array variable with subscript {\b @ }or

{\b *}, the substring operation is applied to each element in turn.

{\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b /}{\i pattern\~}{\b /}{\i string\~}{\b\}

}\tab{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b //}{\i pattern\~}{\b /}{\i string\~}{\b\}

\tab}{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b /#}{\i pattern\~}{\b /}{\i string\~}{\b\}

\tab}{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 $\{}{\i parameter\~}{\b /%}{\i pattern\~}{\b /}{\i string\~}{\b\}

\tab}Expands {\i parameter }and replaces the longest match of {\i pattern

}with the given {\i string. }Each occurrence of {\b\'5c}{\i n\~}in

{\i string }is replaced by the portion of {\i parameter\~}that matches

the {\i n\~}-th sub-pattern. In the first form, only the first occurrence

of {\i pattern }is replaced. In the second form, each match for {\i pattern

}is replaced by the given {\i string. }The third form restricts the pattern

match to the beginning of the string while the fourth form restricts the

pattern match to the end of the string. When {\i string }is null, the {\i pattern

}will be deleted and the {\b / }in front of {\i string }may

be omitted. When {\i parameter }is {\b @}, {\b *}, or

an array variable with subscript {\b @ }or {\b *}, the

substitution operation is applied to each element in turn. \par\pard\qc\li840\tx840\tx20000 In the above,

{\i word }is not evaluated unless it is to be used as the substituted string,

so that, in the following example, {\b pwd }is executed only if

{\b d }is not set or is null: \par\pard\qc\li1120\tx1120\tx20000 print \~$\{d:\'2d\~$(\~pwd\~)\~\}

\par\pard\qc\li840\tx840\tx20000 If the colon ( {\b : ) }is omitted from the above expressions,

then the shell only checks whether {\i parameter }is set or not. \par\pard\qc\li840\tx840\tx20000 The

following parameters are automatically set by the shell: {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 #

}\tab The number of positional parameters in decimal. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d

}\tab Options supplied to the shell on invocation or by the {\b set

}command. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 ? }\tab The decimal value returned by the last

executed command. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 $ }\tab The process number of this shell.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 _ }\tab Initially, the value of {\b _ }is an absolute

pathname of the shell or script being executed as passed in the {\i environment}.

Subsequently it is assigned the last argument of the previous command. This

parameter is not set for commands which are asynchronous. This parameter

is also used to hold the name of the matching {\b{\fs22 MAIL }}file

when checking for mail. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 ! }\tab The process number of the last

background command invoked. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 .sh.edchar }\tab This variable

contains the value of the keyboard character (or sequence of characters

if the first character is an ESC, ascii {\b 033\~}) that has

been entered when processing a {\b{\fs22 KEYBD }}trap (see

{\uldb Key Bindings}{\v HTML2RTF.Key.Bindings}{\*\comment{\i Key Bindings }}below). If the value is changed as

part of the trap action, then the new value replaces the key (or key sequence)

that caused the trap. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 .sh.edcol }\tab The character position

of the cursor at the time of the most recent {\b{\fs22 KEYBD }}trap.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 .sh.edmode }\tab The value is set to ESC when processing a

{\b{\fs22 KEYBD }}trap while in {\b vi }insert

mode. (See {\i Vi Editing Mode }below.) Otherwise, {\b .sh.edmode }is

null when processing a {\b{\fs22 KEYBD }}trap. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 .sh.edtext

}\tab The characters in the input buffer at the time of the most recent

{\b{\fs22 KEYBD }}trap. The value is null when not processing

a {\b{\fs22 KEYBD }}trap. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 .sh.name }\tab Set

to the name of the variable at the time that a discipline function is invoked.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 .sh.subscript }\tab Set to the name subscript of the variable

at the time that a discipline function is invoked. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 .sh.value }\tab Set

to the value of the variable at the time that the {\b set }discipline

function is invoked. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 .sh.version }\tab Set to a value that

identifies the version of this shell. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 LINENO }}\tab The

current line number within the script or function being executed. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 OLDPWD

}}\tab The previous working directory set by the {\b cd }command.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 OPTARG }}\tab The value of the last option argument

processed by the {\b getopts }built-in command. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 OPTIND

}}\tab The index of the last option argument processed by the {\b getopts

}built-in command. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 PPID }}\tab The process

number of the parent of the shell. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 PWD }}\tab The

present working directory set by the {\b cd }command. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 RANDOM

}}\tab Each time this variable is referenced, a random integer,

uniformly distributed between 0 and 32767, is generated. The sequence of

random numbers can be initialized by assigning a numeric value to {\fs22{\b RANDOM}.

}{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 REPLY }}\tab This variable is set by the

{\b select }statement and by the {\b read }built-in command

when no arguments are supplied. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 SECONDS }}\tab Each

time this variable is referenced, the number of seconds since shell invocation

is returned. If this variable is assigned a value, then the value returned

upon reference will be the value that was assigned plus the number of seconds

since the assignment. \par\pard\qc\li840\tx840\tx20000 The following variables are used by the shell:

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 CDPATH }}\tab The search path

for the {\b cd }command. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 COLUMNS }}\tab If

this variable is set, the value is used to define the width of the edit

window for the shell edit modes and for printing {\b select }lists.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 EDITOR }}\tab If the value of this variable ends

in {\i emacs}, {\i gmacs}, or {\i vi }and the {\b{\fs22 VISUAL

}}variable is not set, then the corresponding option (see special

built-in command {\uldb set}{\v HTML2RTF.set}{\*\comment{\b set }}below) will be turned on.

\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22{\b ENV }\tab}If this variable is set, then parameter

expansion, command substitution, and arithmetic substitution are performed

on the value to generate the pathname of the script that will be executed

when the shell is invoked (see {\uldb Invocation}{\v HTML2RTF.Invocation}{\*\comment{\i Invocation }}below).

This file is typically used for {\b alias }and {\b function

}definitions. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 FCEDIT }}\tab Obsolete name

for the default editor name for the {\b hist }command. {\b{\fs22 FCEDIT

}}is not used when {\b{\fs22 HISTEDIT }}is set.

\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22{\b FIGNORE }\tab}A pattern that defines the set

of filenames that will be ignored when performing filename matching. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22{\b FPATH

}\tab}The search path for function definitions. This path is searched

for a file with the same name as the function or command when a function

with the {\b\'2d u }attribute is referenced and when a command

is not found. If an executable file with the name of that command is found,

then it is read and executed in the current environment. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 HISTCMD

}}\tab Number of the current command in the history file. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 HISTEDIT

}}\tab Name for the default editor name for the {\b hist }command.

\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22{\b HISTFILE }\tab}If this variable is set when the

shell is invoked, then the value is the pathname of the file that will be

used to store the command history (see {\uldb Command Re-entry}{\v HTML2RTF.Command.Re.entry}{\*\comment{\i Command

Re-entry }}below). \par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22{\b HISTSIZE }\tab}If this

variable is set when the shell is invoked, then the number of previously

entered commands that are accessible by this shell will be greater than

or equal to this number. The default is 128. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 HOME }}\tab The

default argument (home directory) for the {\b cd }command. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22{\b IFS

}\tab}Internal field separators, normally {\b space}, {\b tab},

and {\b new-line }that are used to separate the results of command

substitution or parameter expansion and to separate fields with the built-in

command {\b read}. The first character of the {\fs22{\b IFS

}}variable is used to separate arguments for the {\b "$*" }substitution

(see {\uldb Quoting}{\v HTML2RTF.Quoting}{\*\comment{\i Quoting }}below). Each single occurrence of an {\fs22{\b IFS

}}character in the string to be split, that is not in the {\i isspace\~}character

class, and any adjacent characters in {\fs22{\b IFS }}that

are in the {\i isspace\~}character class, delimit a field. One or more

characters in {\fs22{\b IFS }}that belong to the {\i isspace\~}character

class, delimit a field. In addition, if the same {\i isspace\~}character

appears consecutively inside {\fs22{\b IFS}, }this character

is treated as if it were not in the {\i isspace\~}class, so that if

{\fs22{\b IFS }}consists of two {\b tab }characters,

then two adjacent {\b tab }characters delimit a null field. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 LANG

}}\tab This variable determines the locale category for any category

not specifically selected with a variable starting with {\b{\fs22 LC_

}}or {\fs22{\b LANG}. }{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 LC_ALL

}}\tab This variable overrides the value of the {\b{\fs22 LANG

}}variable and any other {\b{\fs22 LC_ }}variable.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 LC_COLLATE }}\tab This variable determines the

locale category for character collation information. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 LC_CTYPE

}}\tab This variable determines the locale category for character

handling functions. It determines the character classes for pattern matching

(see {\uldb File Name Generation}{\v HTML2RTF.File.Name.Generation}{\*\comment{\i File Name Generation }}below). {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 LC_NUMERIC

}}\tab This variable determines the locale category for the decimal

point character. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 LINES }}\tab If this variable

is set, the value is used to determine the column length for printing {\b select

}lists. Select lists will print vertically until about two-thirds

of {\b{\fs22 LINES }}lines are filled. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 MAIL

}}\tab If this variable is set to the name of a mail file {\i and

}the {\b{\fs22 MAILPATH }}variable is not set, then the

shell informs the user of arrival of mail in the specified file. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 MAILCHECK

}}\tab This variable specifies how often (in seconds) the shell

will check for changes in the modification time of any of the files specified

by the {\b{\fs22 MAILPATH }}or {\b{\fs22 MAIL }}variables.

The default value is 600 seconds. When the time has elapsed the shell will

check before issuing the next prompt. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 MAILPATH }}\tab A

colon ( {\b : }) separated list of file names. If this variable

is set, then the shell informs the user of any modifications to the specified

files that have occurred within the last {\b{\fs22 MAILCHECK }}seconds.

Each file name can be followed by a {\b ? }and a message that will

be printed. The message will undergo parameter expansion, command substitution,

and arithmetic substitution with the variable {\b $_ }defined as

the name of the file that has changed. The default message is {\i you have

mail in $_\~. }{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 PATH }}\tab The search path

for commands (see {\uldb Execution}{\v HTML2RTF.Execution}{\*\comment{\i Execution }}below). The user may

not change {\b{\fs22 PATH} }if executing under {\b rsh

}(except in {\b .profile\~). }\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22{\b PS1

}\tab}The value of this variable is expanded for parameter expansion,

command substitution, and arithmetic substitution to define the primary

prompt string which by default is ``{\b $\~\~\~}''.

The character {\b ! }in the primary prompt string is replaced by

the {\i command }number (see {\uldb Command Re-entry}{\v HTML2RTF.Command.Re.entry}{\*\comment{\i Command Re-entry

}}below). Two successive occurrences of {\b ! }will produce

a single {\b ! }when the prompt string is printed. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22{\b PS2

}\tab}Secondary prompt string, by default ``{\b> \~}''.

\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22{\b PS3 }\tab}Selection prompt string used within

a {\b select }loop, by default ``{\b #? \~}''. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22{\b PS4

}\tab}The value of this variable is expanded for parameter evaluation,

command substitution, and arithmetic substitution and precedes each line

of an execution trace. By default, {\fs22{\b PS4 }}is ``{\b +

\~}''. In addition when {\fs22{\b PS4 }}is unset,

the execution trace prompt is also ``{\b + \~}''. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22{\b SHELL

}\tab}The pathname of the {\i shell }is kept in the environment.

At invocation, if the basename of this variable is {\b rsh}, {\b rksh},

or {\b krsh}, then the shell becomes restricted. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 TMOUT

}}\tab If set to a value greater than zero, {\b{\fs22 TMOUT

}}will be the default timeout value for the {\b read }built-in

command. The {\b select }compound command terminates after {\b{\fs22 TMOUT

}}seconds when input is from a terminal. Otherwise, the shell

will terminate if a line is not entered within the prescribed number of

seconds while reading from a terminal. (Note that the shell can be compiled

with a maximum bound for this value which cannot be exceeded.) {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000{\fs22 VISUAL

}}\tab If the value of this variable ends in {\i emacs}, {\i gmacs},

or {\i vi }then the corresponding option (see Special Command {\uldb set}{\v HTML2RTF.set}{\*\comment{\b set

}}below) will be turned on. The value of {\b{\fs22 VISUAL

}}overrides the value of {\b{\fs22 EDITOR. }}\par\pard\qc\li840\tx840\tx20000 The

shell gives default values to {\b{\fs22 PATH}}, {\b{\fs22 PS1}},

{\b{\fs22 PS2}}, {\b{\fs22 PS3}}, {\b{\fs22 PS4}},

{\b{\fs22 MAILCHECK}}, {\b{\fs22 FCEDIT}},

{\b{\fs22 TMOUT}} and {\b{\fs22 IFS}},

while {\fs22{\b HOME}, }{\fs22{\b SHELL},

}{\fs22{\b ENV}, }and {\fs22{\b MAIL }}are

not set at all by the shell (although {\fs22{\b HOME }}{\i is

}set by {\i login}(1)). On some systems {\fs22{\b MAIL }}and

{\fs22{\b SHELL }}are also set by {\i login}(1). {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Field.Splitting} Field

\~Splitting. \~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}After parameter

expansion and command substitution, the results of substitutions are scanned

for the field separator characters (those found in {\fs22{\b IFS\~}})

and split into distinct fields where such characters are found. Explicit

null fields (\~{\b "\~"} or {\b '\~'}\~)

are retained. Implicit null fields (those resulting from {\i parameters }that

have no values or command substitutions with no output) are removed. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.File.Name.Generation} File

\~Name \~Generation. \~\~\~}\par\pard\qc\li840\tx840\tx20000}}Following

splitting, each field is scanned for the characters {\b *}, {\b ?},

{\b (}, and {\b [\~}unless the {\b\'2d f }option

has been set. If one of these characters appears, then the word is regarded

as a {\i pattern}. Each file name component that contains any pattern character

is replaced with a lexicographically sorted set of names that matches the

pattern from that directory. If no file name is found that matches the pattern,

then that component of the filename is left unchanged. If {\fs22{\b FIGNORE

}}is set, then each file name component that matches the pattern

defined by the value of {\fs22{\b FIGNORE }}is ignored

when generating the matching filenames. The names {\b . }and {\b ..

}are also ignored. If {\fs22{\b FIGNORE }}is not

set, the character {\b . }at the start of each file name component

will be ignored unless the first character of the pattern corresponding

to this component is the character {\b . }itself. Note, that for

other uses of pattern matching the {\b / }and {\b . }are

not treated specially. {\b\par\pard\qc\li1400\tx1400\tx20000\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 * }\tab Matches any

string, including the null string. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 ? }\tab Matches any single

character. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\b [\~}\~.\~.\~.\~{\b\~ ]

}\tab Matches any one of the enclosed characters. A pair of characters

separated by {\b\'2d }matches any character lexically between

the pair, inclusive. If the first character following the opening {\b [\~}is

a {\b ! }then any character not enclosed is matched. A {\b\'2d

}can be included in the character set by putting it as the first or

last character. \line Within {\b [\~}and {\b\~ ]\~},

character classes can be specified with the syntax {\b [:}{\i class}{\b :]}

where class is one of the following classes defined in the ANSI-C standard:

{\b\line alnum alpha blank cntrl digit graph lower print punct space upper

xdigit }\line Within {\b [\~}and {\b\~ ]\~},

an equivalence class can be specified with the syntax {\b [=}{\i c}{\b =]}

which matches all characters with the same primary collation weight (as

defined by the current locale) as the character {\i c}. \line Within {\b [\~}and

{\b\~ ]\~}, {\b [.}{\i symbol}{\b .]}

matches the collating symbol {\i symbol}. A {\i pattern-list }is

a list of one or more patterns separated from each other with a {\b&

}or {\b |}. A {\b& }signifies that all patterns

must be matched whereas {\b | }requires that only one pattern be

matched. Composite patterns can be formed with one or more of the following

sub-patterns: {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 ?(}{\i pattern-list\~}{\b )}

\tab Optionally matches any one of the given patterns. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 *(}{\i pattern-list\~}{\b )}

\tab Matches zero or more occurrences of the given patterns. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 +(}{\i pattern-list\~}{\b )}

\tab Matches one or more occurrences of the given patterns. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 @(}{\i pattern-list\~}{\b )}

\tab Matches exactly one of the given patterns. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 !(}{\i pattern-list\~}{\b )}

\tab Matches anything except one of the given patterns. Each sub-pattern

in a composite pattern is numbered, starting at 1, by the location of the

{\b (} within the pattern. The sequence {\b\'5c}{\i n\~},

where {\i n\~}is a single digit and {\b\'5c}{\i n\~}comes

after the {\i n}-th. sub-pattern, matches the same string as the sub-pattern

itself. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Quoting} Quoting. \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}Each

of the {\i metacharacters }listed earlier (see {\uldb Definitions}{\v HTML2RTF.Definitions}{\*\comment{\i Definitions

}}above) has a special meaning to the shell and causes termination of

a word unless quoted. A character may be {\i quoted }(i.e., made to stand

for itself) by preceding it with a {\b\'5c}. The pair {\b\'5c new-line

}is removed. All characters enclosed between a pair of single quote

marks (\~{\b '\~'}\~) that is not preceded by a {\b $

}are quoted. A single quote cannot appear within the single quotes.

A single quoted string preceded by an unquoted {\b $ }is processed

as an ANSI-C string except that {\b\'5c 0 }within the string

causes the remainder of the string to be ignored and {\b\'5c E }is

equivalent to the escape character (ascii {\b 033}). Inside double

quote marks ({\b "\~"}), parameter and command substitution

occur and {\b\'5c }quotes the characters {\b\'5c},

{\b{\fs26 `}}, {\b "}, and {\b $}.

A {\b $ }in front of a double quoted string will be ignored in

the "C" or "POSIX" locale, and may cause the string to be replaced by a

locale specific string otherwise. The meaning of {\b $* }and {\b $@

}is identical when not quoted or when used as a variable assignment

value or as a file name. However, when used as a command argument, {\b "$*"

}is equivalent to {\b "$1}{\i d}{\b\~ $2}{\i d}\~.\~.\~.{\b "},

where {\i d }is the first character of the {\fs22{\b IFS }}variable,

whereas {\b "$@" }is equivalent to {\b "$1"\~}{\b "$2"\~}.\~.\~.\~.

Inside grave quote marks ({\b{\fs26 `}\~{\fs26 `}}),

{\b\'5c }quotes the characters {\b\'5c}, {\b{\fs26 `}},

and {\b $}. If the grave quotes occur within double quotes, then

{\b\'5c }also quotes the character {\b "}. \par\pard\qc\li840\tx840\tx20000 The special

meaning of reserved words or aliases can be removed by quoting any character

of the reserved word. The recognition of function names or built-in command

names listed below cannot be altered by quoting them. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Arithmetic.Evaluation} Arithmetic

\~Evaluation. \~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}The shell performs

arithmetic evaluation for arithmetic substitution, to evaluate an arithmetic

command, to evaluate an indexed array subscript, and to evaluate arguments

to the built-in commands {\b shift }and {\b let}. Evaluations

are performed using double precision floating point arithmetic. Floating

point constants follow the ANSI-C programming language conventions. Integer

constants are of the form [\~{\i base}{\b #\~}\~]{\i n\~}where

{\i base }is a decimal number between two and sixty-four representing the

arithmetic base and {\i n }is a number in that base. The digits above 9

are represented by the lower case letters, the upper case letters, {\b @},

and {\b _ }respectively. For bases less than or equal to 36, upper

and lower case characters can be used interchangeably. If {\i base }is

omitted, then base 10 is used. \par\pard\qc\li840\tx840\tx20000 An arithmetic expression uses the same

syntax, precedence, and associativity of expression as the C language. All

the C language operators that apply to floating point quantities can be

used. In addition, when the value of an arithmetic variable or sub-expression

can be represented as a long integer, all C language integer arithmetic

operations can be performed. Variables can be referenced by name within

an arithmetic expression without using the parameter expansion syntax. When

a variable is referenced, its value is evaluated as an arithmetic expression.

\par\pard\qc\li840\tx840\tx20000 The following math library functions can be used with an arithmetic expression:

{\b\par\pard\qc\li1120\tx1120\tx20000 abs acos asin atan cos cosh exp int log sin sinh sqrt tan

tanh }\par\pard\qc\li840\tx840\tx20000 An internal representation of a {\i variable }as a double

precision floating point can be specified with the {\b\'2d E}

[\~{\i n\~}\~] or {\b\'2d F} [\~{\i n\~}\~]

option of the {\b typeset }special built-in command. The {\b\'2d E

}option causes the expansion of the value to be represented using

scientific notation when it is expanded. The optional option argument {\i n

}defines the number of significant figures. The {\b\'2d F }option

causes the expansion to be represented as a floating decimal number when

it is expanded. The optional option argument {\i n }defines the number

of places after the decimal point in this case. \par\pard\qc\li840\tx840\tx20000 An internal integer representation

of a {\i variable }can be specified with the {\b\'2d i} [\~{\i n\~}\~]

option of the {\b typeset }special built-in command. The optional

option argument {\i n }specifies an arithmetic base to be used when expanding

the variable. If you do not specify an arithmetic base, the first assignment

to the variable determines the arithmetic base. \par\pard\qc\li840\tx840\tx20000 Arithmetic evaluation

is performed on the value of each assignment to a variable with the {\b\'2d E},

{\b\'2d F}, or {\b\'2d i }attribute. Assigning

a floating point number to a variable whose type is an integer causes the

fractional part to be truncated. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Prompting} Prompting.

\~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}When used interactively,

the shell prompts with the value of {\fs22{\b PS1 }}after

expanding it for parameter expansion, command substitution, and arithmetic

substitution, before reading a command. In addition, each single {\b !

}in the prompt is replaced by the command number. A {\b !! }is

required to place {\b ! }in the prompt. If at any time a new-line

is typed and further input is needed to complete a command, then the secondary

prompt (i.e., the value of {\b{\fs22 PS2}}) is issued.

{\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Conditional.Expressions} Conditional \~Expressions.

\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}A {\i conditional expression }is

used with the {\b [[ }compound command to test attributes of files

and to compare strings. Field splitting and file name generation are not

performed on the words between {\b [[ }and {\b ]]}. Each

expression can be constructed from one or more of the following unary or

binary expressions: {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 string} \tab True, if {\i string }is

not null. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d a} {\i file} \tab Same as {\b\'2d e}

below. This is obsolete. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d b} {\i file} \tab True, if

{\i file }exists and is a block special file. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d c}

{\i file} \tab True, if {\i file }exists and is a character special file.

{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d d} {\i file} \tab True, if {\i file }exists and is

a directory. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d e} {\i file} \tab True, if {\i file }exists.

{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d f} {\i file} \tab True, if {\i file }exists and is

an ordinary file. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d g} {\i file} \tab True, if {\i file

}exists and it has its setgid bit set. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d k} {\i file}

\tab True, if {\i file }exists and it has its sticky bit set. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d n}

{\i string} \tab True, if length of {\i string }is non-zero. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d o}

{\i option} \tab True, if option named {\i option }is on. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d p}

{\i file} \tab True, if {\i file }exists and is a fifo special file or a

pipe. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d r} {\i file} \tab True, if {\i file }exists

and is readable by current process. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d s} {\i file}

\tab True, if {\i file }exists and has size greater than zero. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d t}

{\i fildes} \tab True, if file descriptor number {\i fildes }is open and

associated with a terminal device. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d u} {\i file}

\tab True, if {\i file }exists and it has its setuid bit set. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d w}

{\i file} \tab True, if {\i file }exists and is writable by current process.

{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d x} {\i file} \tab True, if {\i file }exists and is

executable by current process. If {\i file }exists and is a directory,

then true if the current process has permission to search in the directory.

{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d z} {\i string} \tab True, if length of {\i string }is

zero. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d L} {\i file} \tab True, if {\i file }exists

and is a symbolic link. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d O} {\i file} \tab True, if

{\i file }exists and is owned by the effective user id of this process.

{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d G} {\i file} \tab True, if {\i file }exists and its

group matches the effective group id of this process. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d S}

{\i file} \tab True, if {\i file }exists and is a socket. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 file1}

{\b\'2d nt} {\i file2} \tab True, if {\i file1 }exists and

{\i file2 }does not, or {\i file1 }is newer than {\i file2}. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 file1}

{\b\'2d ot} {\i file2} \tab True, if {\i file2 }exists and

{\i file1 }does not, or {\i file1 }is older than {\i file2}. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 file1}

{\b\'2d ef} {\i file2} \tab True, if {\i file1 }and {\i file2

}exist and refer to the same file. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 string} {\b ==} {\i pattern}

\tab True, if {\i string }matches {\i pattern}. Any part of {\i pattern }can

be quoted to cause it to be matched as a string. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 string} {\b =}

{\i pattern} \tab Same as {\b ==} above, but is obsolete. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 string}

{\b !=} {\i pattern} \tab True, if {\i string }does not match {\i pattern}.

{\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 string1} {\b<} {\i string2} \tab True, if {\i string1 }comes

before {\i string2 }based on ASCII value of their characters. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 string1}

{\b>} {\i string2} \tab True, if {\i string1 }comes after {\i string2

}based on ASCII value of their characters. \line The following obsolete

arithmetic comparisons are also permitted: {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 exp1} {\b\'2d eq}

{\i exp2} \tab True, if {\i exp1 }is equal to {\i exp2}. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 exp1} {\b\'2d ne}

{\i exp2} \tab True, if {\i exp1 }is not equal to {\i exp2}. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 exp1}

{\b\'2d lt} {\i exp2} \tab True, if {\i exp1 }is less than

{\i exp2}. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 exp1} {\b\'2d gt} {\i exp2} \tab True, if

{\i exp1 }is greater than {\i exp2}. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 exp1} {\b\'2d le}

{\i exp2} \tab True, if {\i exp1 }is less than or equal to {\i exp2}. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 exp1}

{\b\'2d ge} {\i exp2} \tab True, if {\i exp1 }is greater than

or equal to {\i exp2}. \par\pard\qc\li840\tx840\tx20000 In each of the above expressions, if {\i file

}is of the form {\b /dev/fd/}{\i n}, where {\i n }is an integer,

then the test is applied to the open file whose descriptor number is {\i n}.

\par\pard\qc\li840\tx840\tx20000 A compound expression can be constructed from these primitives by using

any of the following, listed in decreasing order of precedence. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 (}{\i expression}{\b )}

\tab True, if {\i expression }is true. Used to group expressions. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 !}

{\i expression} \tab True if {\i expression }is false. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 expression1}

{\b&&} {\i expression2} \tab True, if {\i expression1 }and

{\i expression2 }are both true. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 expression1} {\b ||} {\i expression2}

\tab True, if either {\i expression1 }or {\i expression2 }is true. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Input.Output} Input/Output.

\~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}Before a command is executed,

its input and output may be redirected using a special notation interpreted

by the shell. The following may appear anywhere in a simple-command or may

precede or follow a {\i command }and are {\i not }passed on to the invoked

command. Command substitution, parameter expansion, and arithmetic substitution

occur before {\i word }or {\i digit }is used except as noted below. File

name generation occurs only if the shell is interactive and the pattern

matches a single file. Field splitting is not performed. \par\pard\qc\li840\tx840\tx20000 In each of the

following redirections, if {\i file }is of the form {\b /dev/tcp/}{\i host}{\b /}{\i port},

or {\b /dev/udp/}{\i host}{\b /}{\i port}, where {\i host

}is a hostname or host address, and {\i port }is an integer port number,

then the redirection attempts to make a {\b tcp} or {\b udp}

connection to the corresponding socket. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000{\b<}{\i word

}\tab Use file {\i word }as standard input (file descriptor 0). \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000{\b>}{\i word

}\tab Use file {\i word }as standard output (file descriptor 1). If the

file does not exist then it is created. If the file exists, and the {\b noclobber

}option is on, this causes an error; otherwise, it is truncated to

zero length. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000{\b> |}{\i word }\tab Sames as {\b>},

except that it overrides the {\b noclobber }option. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000{\b>>}{\i word

}\tab Use file {\i word }as standard output. If the file exists, then output

is appended to it (by first seeking to the end-of-file); otherwise, the

file is created. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000{\b<>}{\i word }\tab Open file {\i word }for

reading and writing as standard input. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000<<}[\~{\b\'2d}\~]{\i word}

\tab The shell input is read up to a line that is the same as {\i word }after

any quoting has been removed, or to an end-of-file. No parameter substitution,

command substitution, arithmetic substitution or file name generation is

performed on {\i word}. The resulting document, called a {\i here-document},

becomes the standard input. If any character of {\i word }is quoted, then

no interpretation is placed upon the characters of the document; otherwise,

parameter expansion, command substitution, and arithmetic substitution occur,

{\b\'5c new-line }is ignored, and {\b\'5c }must

be used to quote the characters {\b\'5c}, {\b $},

{\b{\fs26 `}}. If {\b\'2d }is appended

to {\b<<}, then all leading tabs are stripped from {\i word

}and from the document. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000{\b<&}{\i digit }\tab The standard

input is duplicated from file descriptor {\i digit }(see {\i dup}(2)).

Similarly for the standard output using {\b>&\~}{\i digit}.

\par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000{\b<&}{\i digit}{\b\'2d }\tab The file descriptor

given by {\i digit }is moved to standard input. Similarly for the standard

output using {\b>&\~}{\i digit}{\b\'2d}.

{\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000<&\'2d }\tab The standard input is closed. Similarly

for the standard output using {\b>&\'2d}. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000<& p

}\tab The input from the co-process is moved to standard input. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000>& p

}\tab The output to the co-process is moved to standard output. \par\pard\qc\li840\tx840\tx20000 If

one of the above is preceded by a digit, then the file descriptor number

referred to is that specified by the digit (instead of the default 0 or

1). For example: {\b\par\pard\qc\li1120\tx1120\tx20000 .\~.\~. \~2>&1}

\par\pard\qc\li840\tx840\tx20000 means file descriptor 2 is to be opened for writing as a duplicate

of file descriptor 1. \par\pard\qc\li840\tx840\tx20000 The order in which redirections are specified is

significant. The shell evaluates each redirection in terms of the ({\i file

descriptor}, {\i file}) association at the time of evaluation. For example:

{\b\par\pard\qc\li1120\tx1120\tx20000 .\~.\~. \~1>}{\i fname\~}{\b 2>&1}

\par\pard\qc\li840\tx840\tx20000 first associates file descriptor 1 with file {\i fname\~}. It

then associates file descriptor 2 with the file associated with file descriptor

1 (i.e. {\i fname\~}). If the order of redirections were reversed,

file descriptor 2 would be associated with the terminal (assuming file descriptor

1 had been) and then file descriptor 1 would be associated with file {\i fname\~}.

\par\pard\qc\li840\tx840\tx20000 If a command is followed by {\b& }and job control is not active,

then the default standard input for the command is the empty file {\b /dev/null}.

Otherwise, the environment for the execution of a command contains the file

descriptors of the invoking shell as modified by input/output specifications.

{\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Environment} Environment. \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}The

{\i environment }(see {\i environ}(7)) is a list of name-value

pairs that is passed to an executed program in the same way as a normal

argument list. The names must be {\i identifiers }and the values are character

strings. The shell interacts with the environment in several ways. On invocation,

the shell scans the environment and creates a variable for each name found,

giving it the corresponding value and attributes and marking it {\i export}.

Executed commands inherit the environment. If the user modifies the values

of these variables or creates new ones, using the {\b export }or

{\b typeset \'2dx }commands, they become part of the environment.

The environment seen by any executed command is thus composed of any name-value

pairs originally inherited by the shell, whose values may be modified by

the current shell, plus any additions which must be noted in {\b export

}or {\b typeset \'2dx }commands. \par\pard\qc\li840\tx840\tx20000 The environment for

any {\i simple-command }or function may be augmented by prefixing it with

one or more variable assignments. A variable assignment argument is a word

of the form {\i identifier=value}. Thus: {\b{\fs22\par\pard\qc\li1120\tx1120\tx20000 TERM}=450

\~cmd \~args} and {\b\line (export \~{\fs22 TERM};

\~{\fs22 TERM}=450; \~cmd \~args)} \par\pard\qc\li840\tx840\tx20000 are equivalent

(as far as the above execution of {\i cmd }is concerned except for special

built-in commands listed below \'2d those that are preceded with a dagger).

\par\pard\qc\li840\tx840\tx20000 If the obsolete {\b\'2d k }option is set, {\i all }variable

assignment arguments are placed in the environment, even if they occur after

the command name. The following first prints {\b a=b c }and then

{\b c}: \line

{\b\~\~\~\~\~\~\~\~echo\~\~a=b\~\~c\~\~\~\~\line

\~\~\~\~\~\~\~\~set\~\~\'2dk\~\line

\~\~\~\~\~\~\~\~echo\~\~a=b\~\~c\~\~\~\~\line

}This

feature is intended for use with scripts written for early versions of the

shell and its use in new scripts is strongly discouraged. It is likely to

disappear someday. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Functions} Functions. \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}For

historical reasons, there are two ways to define functions, the {\i name}{\b (\~)

}syntax and the {\b function }{\i name }syntax, described

in the {\i Commands }section above. Shell functions are read in and stored

internally. Alias names are resolved when the function is read. Functions

are executed like commands with the arguments passed as positional parameters.

(See {\i Execution }below.) \par\pard\qc\li840\tx840\tx20000 Functions defined by the {\b function

}{\i name }syntax and called by name execute in the same process

as the caller and share all files and present working directory with the

caller. Traps caught by the caller are reset to their default action inside

the function. A trap condition that is not caught or ignored by the function

causes the function to terminate and the condition to be passed on to the

caller. A trap on {\fs22{\b EXIT }}set inside a function

is executed in the environment of the caller after the function completes.

Ordinarily, variables are shared between the calling program and the function.

However, the {\b typeset }special built-in command used within

a function defines local variables whose scope includes the current function

and all functions it calls. Errors within functions return control to the

caller. \par\pard\qc\li840\tx840\tx20000 Functions defined with the {\i name}{\b (\~) }syntax

and functions defined with the {\b function }{\i name }syntax

that are invoked with the {\b{\fs26 .}} special built-in

are executed in the caller's environment and share all variables and traps

with the caller. Errors within these function executions cause the script

that contains them to abort. \par\pard\qc\li840\tx840\tx20000 The special built-in command {\b return

}is used to return from function calls. \par\pard\qc\li840\tx840\tx20000 Function names can be listed

with the {\b\'2d f }or {\b +f }option of the {\b typeset

}special built-in command. The text of functions, when available,

will also be listed with {\b\'2d f}. Functions can be undefined

with the {\b\'2d f }option of the {\b unset }special

built-in command. \par\pard\qc\li840\tx840\tx20000 Ordinarily, functions are unset when the shell executes

a shell script. Functions that need to be defined across separate invocations

of the shell should be placed in a directory and the {\b{\fs22 FPATH

}}variable should contain the name of this directory. They may

also be specified in the {\b{\fs22 ENV }}file. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Discipline.Functions} Discipline

\~Functions. \~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}Each variable

can have zero or more discipline functions associated with it. The shell

initially understands the discipline names {\b get}, {\b set},

and {\b unset} but on most systems others can be added at run time

via the C programming interface extension provided by the {\b builtin

}built-in utility. If the {\b get} discipline is defined

for a variable, it is invoked whenever the given variable is referenced.

If the variable {\b .sh.value} is assigned a value inside the discipline

function, the referenced variable will evaluate to this value instead. If

the {\b set} discipline is defined for a variable, it is invoked

whenever the given variable is assigned a value. The variable {\b .sh.value}

is given the value of the variable before invoking the discipline, and the

variable will be assigned the value of {\b .sh.value} after the

discipline completes. If {\b .sh.value} is unset inside the discipline,

then that value is unchanged. If the {\b unset} discipline is defined

for a variable, it is invoked whenever the given variable is unset. The

variable will not be unset unless it is unset explicitly from within this

discipline function. \par\pard\qc\li840\tx840\tx20000 The variable {\b .sh.name }contains the

name of the variable for which the discipline function is called, {\b .sh.subscript

}is the subscript of the variable, and {\b .sh.value }will

contain the value being assigned inside the {\b .set }discipline

function. For the {\b set} discipline, changing {\b .sh.value

}will change the value that gets assigned. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Jobs} Jobs.

\~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}If the {\b monitor }option

of the {\b set }command is turned on, an interactive shell associates

a {\i job} with each pipeline. It keeps a table of current jobs, printed

by the {\b jobs }command, and assigns them small integer numbers.

When a job is started asynchronously with {\b&}, the shell prints

a line which looks like: \par\pard\qc\li840\tx840\tx20000 [1] 1234 \par\pard\qc\li840\tx840\tx20000 indicating that the job which was

started asynchronously was job number 1 and had one (top-level) process,

whose process id was 1234. \par\pard\qc\li840\tx840\tx20000 This paragraph and the next require features

that are not in all versions of UNIX and may not apply. If you are running

a job and wish to do something else you may hit the key {\b ^Z}

(control-Z) which sends a STOP signal to the current job. The shell will

then normally indicate that the job has been `Stopped', and print another

prompt. You can then manipulate the state of this job, putting it in the

background with the {\b bg }command, or run some other commands

and then eventually bring the job back into the foreground with the foreground

command {\b fg}. A {\b ^Z} takes effect immediately and

is like an interrupt in that pending output and unread input are discarded

when it is typed. \par\pard\qc\li840\tx840\tx20000 A job being run in the background will stop if it tries

to read from the terminal. Background jobs are normally allowed to produce

output, but this can be disabled by giving the command {\b stty tostop}.

If you set this tty option, then background jobs will stop when they try

to produce output like they do when they try to read input. \par\pard\qc\li840\tx840\tx20000 There are

several ways to refer to jobs in the shell. A job can be referred to by

the process id of any process of the job or by one of the following: \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b %}{\i number

}\tab The job with the given number. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b %}{\i string }\tab Any

job whose command line begins with {\i string}. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b %?}{\i string

}\tab Any job whose command line contains {\i string}. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b %% }\tab Current

job. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b %+ }\tab Equivalent to {\b %%}. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b %\'2d

}\tab Previous job. \par\pard\qc\li840\tx840\tx20000 The shell learns immediately whenever a process

changes state. It normally informs you whenever a job becomes blocked so

that no further progress is possible, but only just before it prints a prompt.

This is done so that it does not otherwise disturb your work. The {\b notify

}option of the {\b set }command causes the shell to print

these job change messages as soon as they occur. \par\pard\qc\li840\tx840\tx20000 When the {\b monitor

}option is on, each background job that completes triggers any trap

set for {\b CHLD}. \par\pard\qc\li840\tx840\tx20000 When you try to leave the shell while jobs

are running or stopped, you will be warned that `You have stopped(running)

jobs.' You may use the {\b jobs }command to see what they are.

If you immediately try to exit again, the shell will not warn you a second

time, and the stopped jobs will be terminated. When a login shell receives

a HUP signal, it sends a HUP signal to each job that has not been disowned

with the {\b disown }built-in command described below. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Signals} Signals.

\~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}The {\fs22 INT}

and {\fs22 QUIT} signals for an invoked command are ignored if the

command is followed by {\b& }and the {\b monitor }option

is not active. Otherwise, signals have the values inherited by the shell

from its parent (but see also the {\b trap }built-in command below).

{\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Execution} Execution. \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}Each

time a command is read, the above substitutions are carried out. If the

command name matches one of the {\i Special Built-in Commands }listed below,

it is executed within the current shell process. Next, the command name

is checked to see if it matches a user defined function. If it does, the

positional parameters are saved and then reset to the arguments of the {\i function

}call. A function is also executed in the current shell process. When

the {\i function }completes or issues a {\b return}, the positional

parameter list is restored. For functions defined with the {\b function

}{\i name }syntax, any trap set on {\fs22{\b EXIT }}within

the function is executed. The exit value of a {\i function }is the value

of the last command executed. If a command name is not a {\i special built-in

command }or a user defined {\i function}, but it is one of the built-in

commands listed below, it is executed in the current shell process. \par\pard\qc\li840\tx840\tx20000 The

shell variable {\b{\fs22 PATH }}defines the search path

for the directory containing the command. Alternative directory names are

separated by a colon ({\b :}). The default path is {\b /bin:/usr/bin:

}(specifying {\b /bin}, {\b /usr/bin}, and the current

directory in that order). The current directory can be specified by two

or more adjacent colons, or by a colon at the beginning or end of the path

list. If the command name contains a {\b /}, then the search path

is not used. Otherwise, each directory in the path is searched for an executable

file that is not a directory. If the shell determines that there is a built-in

version of a command corresponding to a given pathname, this built-in is

invoked in the current process. A process is created and an attempt is made

to execute the command via {\i exec}(2). If the file has execute permission

but is not an {\b a.out }file, it is assumed to be a file containing

shell commands. A separate shell is spawned to read it. All non-exported

variables are removed in this case. If the shell command file doesn't have

read permission, or if the {\i setuid }and/or {\i setgid }bits are set

on the file, then the shell executes an agent whose job it is to set up

the permissions and execute the shell with the shell command file passed

down as an open file. A parenthesized command is executed in a sub-shell

without removing non-exported variables. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Command.Re.entry} Command

\~Re-entry. \~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}The text of the

last {\b{\fs22 HISTSIZE }}(default 128) commands entered

from a terminal device is saved in a {\i history }file. The file {\b{\fs22 $HOME}/.sh_history

}is used if the {\b{\fs22 HISTFILE }}variable is

not set or if the file it names is not writable. A shell can access the

commands of all {\i interactive }shells which use the same named {\fs22{\b HISTFILE}.

}The built-in command {\b hist }is used to list or edit a portion

of this file. The portion of the file to be edited or listed can be selected

by number or by giving the first character or characters of the command.

A single command or range of commands can be specified. If you do not specify

an editor program as an argument to {\b hist }then the value of

the variable {\fs22{\b HISTEDIT }}is used. If {\fs22{\b HISTEDIT

}}is unset, the obsolete variable {\fs22{\b FCEDIT }}is

used. If {\fs22{\b FCEDIT }}is not defined, then {\b /bin/ed

}is used. The edited command(s) is printed and re-executed upon leaving

the editor unless you quit without writing. The {\b\'2d s }option

(and in obsolete versions, the editor name {\b\'2d\~})

is used to skip the editing phase and to re-execute the command. In this

case a substitution parameter of the form {\i old}{\b =}{\i new}

can be used to modify the command before execution. For example, with the

preset alias {\b r}, which is aliased to {\b 'hist \'2ds'},

typing `{\b r bad=good c}' will re-execute the most recent command

which starts with the letter {\b c}, replacing the first occurrence

of the string {\b bad }with the string {\b good}. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.In.line.Editing.Options} In-line

\~Editing \~Options. \~\~\~}\par\pard\qc\li840\tx840\tx20000}}Normally,

each command line entered from a terminal device is simply typed followed

by a {\b new-line} (`RETURN' or `LINE\~FEED'). If either the

{\b emacs}, {\b gmacs}, or {\b vi }option is

active, the user can edit the command line. To be in either of these edit

modes {\b set }the corresponding option. An editing option is automatically

selected each time the {\fs22{\b VISUAL }}or {\fs22{\b EDITOR

}}variable is assigned a value ending in either of these option

names. \par\pard\qc\li840\tx840\tx20000 The editing features require that the user's terminal accept `RETURN'

as carriage return without line feed and that a space (`\~') must overwrite

the current character on the screen. \par\pard\qc\li840\tx840\tx20000 The editing modes implement a concept

where the user is looking through a window at the current line. The window

width is the value of {\fs22{\b COLUMNS }}if it is defined,

otherwise 80. If the window width is too small to display the prompt and

leave at least 8 columns to enter input, the prompt is truncated from the

left. If the line is longer than the window width minus two, a mark is displayed

at the end of the window to notify the user. As the cursor moves and reaches

the window boundaries the window will be centered about the cursor. The

mark is a {\b>} (<{\b , }{\b *}) if the line

extends on the right (left, both) side(s) of the window. \par\pard\qc\li840\tx840\tx20000 The search commands

in each edit mode provide access to the history file. Only strings are matched,

not patterns, although a leading {\b ^ }in the string restricts

the match to begin at the first character in the line. \par\pard\qc\li840\tx840\tx20000 Each of the edit

modes has an operation to list the files or commands that match a partially

entered word. When applied to the first word on the line, or the first word

after a {\b ;}, {\b |}, {\b&}, or {\b (},

and the word does not begin with {\b ~ }or contain a {\b /},

the list of aliases, functions, and executable commands defined by the {\b{\fs22 PATH

}}variable that could match the partial word is displayed. Otherwise,

the list of files that match the given word is displayed. If the partially

entered word does not contain any file expansion characters, a {\b *

}is appended before generating these lists. After displaying the generated

list, the input line is redrawn. These operations are called command name

listing and file name listing, respectively. There are additional operations,

referred to as command name completion and file name completion, which compute

the list of matching commands or files, but instead of printing the list,

replace the current word with a complete or partial match. For file name

completion, if the match is unique, a {\b / }is appended if the

file is a directory and a space is appended if the file is not a directory.

Otherwise, the longest common prefix for all the matching files replaces

the word. For command name completion, only the portion of the file names

after the last {\b / }are used to find the longest command prefix.

If only a single name matches this prefix, then the word is replaced with

the command name followed by a space. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Key.Bindings} Key

\~Bindings. \~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}The {\b{\fs22 KEYBD

}}trap can be used to intercept keys as they are typed and change

the characters that are actually seen by the shell. This trap is executed

after each character (or sequence of characters when the first character

is ESC) is entered while reading from a terminal. The variable {\b .sh.edchar

}contains the character or character sequence which generated the

trap. Changing the value of {\b .sh.edchar }in the trap action

causes the shell to behave as if the new value were entered from the keyboard

rather than the original value. \par\pard\qc\li840\tx840\tx20000 The variable {\b .sh.edcol }is

set to the input column number of the cursor at the time of the input. The

variable {\b .sh.edmode }is set to ESC when in {\b vi }insert

mode (see below) and is null otherwise. By prepending {\b $\{.sh.editmode\}

}to a value assigned to {\b .sh.edchar }it will cause the

shell to change to control mode if it is not already in this mode. \par\pard\qc\li840\tx840\tx20000 This

trap is not invoked for characters entered as arguments to editing directives,

or while reading input for a character search. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Emacs.Editing.Mode} Emacs

\~Editing \~Mode. \~\~\~}\par\pard\qc\li840\tx840\tx20000}}This mode

is entered by enabling either the {\b emacs }or {\b gmacs }option.

The only difference between these two modes is the way they handle {\b ^T}.

To edit, the user moves the cursor to the point needing correction and then

inserts or deletes characters or words as needed. All the editing commands

are control characters or escape sequences. The notation for control characters

is caret ({\b ^}) followed by the character. For example, {\b ^F

}is the notation for control {\b F}. This is entered by depressing

`f' while holding down the `CTRL' (control) key. The `SHIFT' key is {\i not

}depressed. (The notation {\b ^? }indicates the DEL (delete)

key.) \par\pard\qc\li840\tx840\tx20000 The notation for escape sequences is {\b M- }followed by

a character. For example, {\b M-f }(pronounced Meta f) is entered

by depressing ESC (ascii {\b 033}) followed by `f'. ({\b M-F

}would be the notation for ESC followed by `SHIFT' (capital) `F'.)

\par\pard\qc\li840\tx840\tx20000 All edit commands operate from any place on the line (not just at the

beginning). Neither the `RETURN' nor the `LINE FEED' key is entered after

edit commands except when noted. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^F }\tab Move cursor

forward (right) one character. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-f }\tab Move cursor forward

one word. (The {\b emacs }editor's idea of a word is a string of

characters consisting of only letters, digits and underscores.) \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^B

}\tab Move cursor backward (left) one character. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-b }\tab Move

cursor backward one word. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^A }\tab Move cursor to start of

line. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^E }\tab Move cursor to end of line. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^]}{\i char

}\tab Move cursor forward to character {\i char }on current line. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-^]}{\i char

}\tab Move cursor backward to character {\i char }on current line. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^X^X

}\tab Interchange the cursor and mark. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 erase }\tab (User defined

erase character as defined by the {\i stty}(1) command, usually {\b ^H

}or {\b #}.) Delete previous character. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^D }\tab Delete

current character. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-d }\tab Delete current word. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-^H

}\tab (Meta-backspace) Delete previous word. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-h }\tab Delete

previous word. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-^? }\tab (Meta-DEL) Delete previous word (if

your interrupt character is {\b ^? }(DEL, the default) then this

command will not work). \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^T }\tab Transpose current character

with previous character and advance the cursor in {\i emacs }mode. Transpose

two previous characters in {\i gmacs }mode. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^C }\tab Capitalize

current character. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-c }\tab Capitalize current word. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-l

}\tab Change the current word to lower case. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^K }\tab Delete

from the cursor to the end of the line. If preceded by a numerical parameter

whose value is less than the current cursor position, then delete from given

position up to the cursor. If preceded by a numerical parameter whose value

is greater than the current cursor position, then delete from cursor up

to given cursor position. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^W }\tab Kill from the cursor to

the mark. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-p }\tab Push the region from the cursor to the

mark on the stack. {\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 kill }\tab (User defined kill character as defined

by the stty command, usually {\b ^G }or {\b @}.) Kill

the entire current line. If two {\i kill }characters are entered in succession,

all kill characters from then on cause a line feed (useful when using paper

terminals). \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^Y }\tab Restore last item removed from line. (Yank

item back to the line.) \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^L }\tab Line feed and print current

line. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^@ }\tab (Null character) Set mark. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-}{\i space

}\tab (Meta space) Set mark. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^J }\tab (New\~line) Execute

the current line. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^M }\tab (Return) Execute the current line.

{\i\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 eof }\tab End-of-file character, normally {\b ^D}, is processed

as an End-of-file only if the current line is null. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^P }\tab Fetch

previous command. Each time {\b ^P }is entered the previous command

back in time is accessed. Moves back one line when not on the first line

of a multi-line command. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-< }\tab Fetch the least recent

(oldest) history line. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-> }\tab Fetch the most recent (youngest)

history line. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^N }\tab Fetch next command line. Each time {\b ^N

}is entered the next command line forward in time is accessed. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^R}{\i string

}\tab Reverse search history for a previous command line containing {\i string}.

If a parameter of zero is given, the search is forward. {\i String }is

terminated by a `RETURN' or `NEW\~LINE'. If string is preceded by a

{\b ^}, the matched line must begin with {\i string}. If {\i string

}is omitted, then the next command line containing the most recent {\i string

}is accessed. In this case a parameter of zero reverses the direction

of the search. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 ^O }\tab Operate \'2d Execute the current

line and fetch the next line relative to current line from the history file.

\par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-}{\i digits }\tab (Escape) Define numeric parameter, the

digits are taken as a parameter to the next command. The commands that accept

a parameter are {\b ^F}, {\b ^B}, {\i erase}, {\b ^C},

{\b ^D}, {\b ^K}, {\b ^R}, {\b ^P},

{\b ^N}, {\b ^]}, {\b M-.}, {\b M-^]},

{\b M-_}, {\b M-b}, {\b M-c}, {\b M-d},

{\b M-f}, {\b M-h}, {\b M-l }and {\b M-^H}.

\par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-}{\i letter }\tab Soft-key \'2d Your alias list is searched

for an alias by the name {\b _}{\i letter }and if an alias of

this name is defined, its value will be inserted on the input queue. The

{\i letter }must not be one of the above meta-functions. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b M-[}{\i letter

}\tab Soft-key \'2d Your alias list is searched for an alias by the

name {\b __}{\i letter }and if an alias of this name is defined,

its value will be inserted on the input queue. The can be used to program

functions keys on many terminals. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 M-. }\tab The last word of

the previous command is inserted on the line. If preceded by a numeric parameter,

the value of this parameter determines which word to insert rather than

the last word. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 M-_ }\tab Same as {\b M-.}. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 M-*

}\tab Attempt file name generation on the current word. An asterisk

is appended if the word doesn't match any file or contain any special pattern

characters. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 M-ESC }\tab Command or file name completion as

described above. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 M-= }\tab Command or file name listing as

described above. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b ^U }\tab Multiply parameter of next command

by 4. \par\pard\qc\fi-560\li1120\tx1120\tx20000{\b\'5c }\tab Escape next character. Editing characters,

the user's erase, kill and interrupt (normally {\b ^?}) characters

may be entered in a command line or in a search string if preceded by a

{\b\'5c}. The {\b\'5c }removes the next character's

editing features (if any). {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 ^V }\tab Display version of the

shell. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 M-# }\tab If the line does not begin with a {\b #},

a {\b # }is inserted at the beginning of the line and after each

new-line, and the line is entered. This causes a comment to be inserted

in the history file. If the line begins with a {\b #}, the {\b #

}is deleted and one {\b # }after each new-line is also deleted.

{\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Vi.Editing.Mode} Vi \~Editing \~Mode.

\~\~\~}\par\pard\qc\li840\tx840\tx20000}}There are two typing modes. Initially,

when you enter a command you are in the {\i input }mode. To edit, the user

enters {\i control }mode by typing ESC ({\b 033}) and moves the

cursor to the point needing correction and then inserts or deletes characters

or words as needed. Most control commands accept an optional repeat {\i count

}prior to the command. \par\pard\qc\li840\tx840\tx20000 When in {\b vi }mode on most systems,

canonical processing is initially enabled and the command will be echoed

again if the speed is 1200 baud or greater and it contains any control characters

or less than one second has elapsed since the prompt was printed. The ESC

character terminates canonical processing for the remainder of the command

and the user can then modify the command line. This scheme has the advantages

of canonical processing with the type-ahead echoing of raw mode. \par\pard\qc\li840\tx840\tx20000 If the

option {\b viraw }is also set, the terminal will always have canonical

processing disabled. This mode is implicit for systems that do not support

two alternate end of line delimiters, and may be helpful for certain terminals.

{\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Input.Edit.Commands}\~\~\~\~\~ Input

Edit Commands \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}By

default the editor is in input mode. {\i\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 erase }\tab (User defined

erase character as defined by the stty command, usually {\b ^H }or

{\b #}.) Delete previous character. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\b ^W }\tab Delete

the previous blank separated word. On some systems the {\b viraw}

option may be required for this to work. {\i\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 eof }\tab As the first character

of the line causes the shell to terminate unless the {\b ignoreeof}

option is set. Otherwise this character is ignored. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\b ^V }\tab Escape

next character. Editing characters and the user's erase or kill characters

may be entered in a command line or in a search string if preceded by a

{\b ^V}. The {\b ^V }removes the next character's editing

features (if any). On some systems the {\b viraw} option may be

required for this to work. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\b\'5c }\tab Escape the next {\i erase

}or {\i kill }character. {\fs22{\b\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Motion.Edit.Commands}\~\~\~\~\~ Motion

Edit Commands \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}These

commands will move the cursor. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b l}

\tab Cursor forward (right) one character. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b w}

\tab Cursor forward one alpha-numeric word. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b W}

\tab Cursor to the beginning of the next word that follows a blank. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b e}

\tab Cursor to end of word. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b E} \tab Cursor to end

of the current blank delimited word. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b h} \tab Cursor

backward (left) one character. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b b} \tab Cursor

backward one word. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b B} \tab Cursor to preceding

blank separated word. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b |} \tab Cursor to column

{\i count}. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b f}{\i c} \tab Find the next character

{\i c} in the current line. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b F}{\i c} \tab Find

the previous character {\i c} in the current line. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b t}{\i c}

\tab Equivalent to {\b f }followed by {\b h}. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b T}{\i c}

\tab Equivalent to {\b F }followed by {\b l}. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b ;}

\tab Repeats {\i count }times, the last single character find command, {\b f},

{\b F}, {\b t}, or {\b T}. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b ,}

\tab Reverses the last single character find command {\i count }times. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 0

}\tab Cursor to start of line. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 ^ }\tab Cursor to first

non-blank character in line. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 $ }\tab Cursor to end of line.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 % }\tab Moves to balancing {\b (}, {\b )},

{\b\{}, {\b\}}, {\b [}, or {\b ]}. If

cursor is not on one of the above characters, the remainder of the line

is searched for the first occurrence of one of the above characters first.

{\fs22{\b\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Search.Edit.Commands}\~\~\~\~\~ Search

Edit Commands \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}These

commands access your command history. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b k}

\tab Fetch previous command. Each time {\b k }is entered the previous

command back in time is accessed. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b\'2d}

\tab Equivalent to {\b k}. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b j} \tab Fetch

next command. Each time {\b j }is entered the next command forward

in time is accessed. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b +} \tab Equivalent to {\b j}.

\par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b G} \tab The command number {\i count }is fetched.

The default is the least recent history command. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\b /}{\i string

}\tab Search backward through history for a previous command containing

{\i string}. {\i String }is terminated by a `RETURN' or `NEW\~LINE'.

If string is preceded by a {\b ^}, the matched line must begin

with {\i string}. If {\i string} is null, the previous string will be

used. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\b ?}{\i string }\tab Same as {\b / }except that

search will be in the forward direction. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 n }\tab Search for

next match of the last pattern to {\b / }or {\b ? }commands.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 N }\tab Search for next match of the last pattern to {\b /

}or {\b ?}, but in reverse direction. {\fs22{\b\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Text.Modification.Edit.Commands}\~\~\~\~\~ Text

Modification Edit Commands \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}These

commands will modify the line. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 a }\tab Enter input

mode and enter text after the current character. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 A }\tab Append

text to the end of the line. Equivalent to {\b $a}. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b c}{\i motion}

\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 c}[{\i count}]{\i motion} \tab Delete current character

through the character that {\i motion }would move the cursor to and enter

input mode. If {\i motion} is {\b c}, the entire line will be

deleted and input mode entered. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 C }\tab Delete the current

character through the end of line and enter input mode. Equivalent to {\b c$}.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 S }\tab Equivalent to {\b cc}. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b s}

\tab Replace characters under the cursor in input mode. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 D }\tab Delete

the current character through the end of line. Equivalent to {\b d$}.

\par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b d}{\i motion} \tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 d}[{\i count}]{\i motion}

\tab Delete current character through the character that {\i motion }would

move to. If {\i motion} is {\b d , }the entire line will be deleted.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 i }\tab Enter input mode and insert text before the current

character. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 I }\tab Insert text before the beginning of the

line. Equivalent to {\b 0i}. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b P} \tab Place

the previous text modification before the cursor. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b p}

\tab Place the previous text modification after the cursor. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 R }\tab Enter

input mode and replace characters on the screen with characters you type

overlay fashion. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b r}{\i c} \tab Replace the {\i count

}character(s) starting at the current cursor position with {\i c}, and

advance the cursor. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b x} \tab Delete current character.

\par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b X} \tab Delete preceding character. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b .}

\tab Repeat the previous text modification command. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b ~}

\tab Invert the case of the {\i count }character(s) starting at the current

cursor position and advance the cursor. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b _}

\tab Causes the {\i count }word of the previous command to be appended and

input mode entered. The last word is used if {\i count }is omitted. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 *

}\tab Causes an {\b * }to be appended to the current word and

file name generation attempted. If no match is found, it rings the bell.

Otherwise, the word is replaced by the matching pattern and input mode is

entered. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'5c }\tab Command or file name completion as described

above. {\fs22{\b\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Other.Edit.Commands}\~\~\~\~\~ Other

Edit Commands \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}Miscellaneous

commands. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b y}{\i motion} \tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 y}[{\i count}]{\i motion}

\tab Yank current character through character that {\i motion }would move

the cursor to and puts them into the delete buffer. The text and cursor

are unchanged. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 yy }\tab Yanks the entire line. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 Y }\tab Yanks

from current position to end of line. Equivalent to {\b y$}. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 u

}\tab Undo the last text modifying command. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 U }\tab Undo

all the text modifying commands performed on the line. \par\pard\qc\fi-560\li1400\tx1400\tx20000 [{\i count}]{\b v}

\tab Returns the command {\b hist \'2de $\{{\fs22 VISUAL}:\'2d$\{{\fs22 EDITOR}:\'2dvi\}\}}{\i

count }in the input buffer. If {\i count }is omitted, then the current

line is used. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\b ^L }\tab Line feed and print current line. Has

effect only in control mode. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\b ^J }\tab (New\~line) Execute

the current line, regardless of mode. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\b ^M }\tab (Return) Execute

the current line, regardless of mode. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 # }\tab If the first

character of the command is a {\b #}, then this command deletes

this {\b # }and each {\b # }that follows a newline. Otherwise,

sends the line after inserting a {\b # }in front of each line in

the command. Useful for causing the current line to be inserted in the history

as a comment and uncommenting previously commented commands in the history

file. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000 = }\tab Command or file name listing as described above.

\par\pard\qc\fi-560\li1400\tx1400\tx20000{\b @}{\i letter }\tab Your alias list is searched for an alias

by the name {\b _}{\i letter }and if an alias of this name is

defined, its value will be inserted on the input queue for processing. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\b ^V

}\tab Display version of the shell. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Built.in.Commands} Built-in

\~Commands. \~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}The following

simple-commands are executed in the shell process. Input/Output redirection

is permitted. Unless otherwise indicated, the output is written on file

descriptor 1 and the exit status, when there is no syntax error, is zero.

Except for {\b :}, {\b true}, {\b false}, {\b echo},

{\b command}, {\b newgrp}, and {\b login}, all

built-in commands accept {\b\'2d\'2d }to indicate end of

options. They also interpret the option {\b\'2d ? }as a help

request and print a {\i usage }message on standard error. Commands that

are preceded by one or two \'a7 symbols are special built-in commands

and are treated specially in the following ways: \par\pard\qc\fi-560\li1120\tx1120\tx20000 1. \tab Variable

assignment lists preceding the command remain in effect when the command

completes. \par\pard\qc\fi-560\li1120\tx1120\tx20000 2. \tab I/O redirections are processed after variable assignments.

\par\pard\qc\fi-560\li1120\tx1120\tx20000 3. \tab Errors cause a script that contains them to abort. \par\pard\qc\fi-560\li1120\tx1120\tx20000 4. \tab They

are not valid function names. \par\pard\qc\fi-560\li1120\tx1120\tx20000 5. \tab Words following a command preceded

by \'a7\'a7 that are in the format of a variable assignment are

expanded with the same rules as a variable assignment. This means that tilde

substitution is performed after the {\b = }sign and field splitting

and file name generation are not performed. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b :}

[\~{\i arg\~}.\~.\~. \~] \tab The command only expands

parameters. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b\~ . }{\i name\~}{\b [\~}{\i arg\~}{\b .\~.\~.

\~] \tab}If {\i name }is a function defined with the {\b function

}{\i name }reserved word syntax, the function is executed in the

current environment (as if it had been defined with the {\i name}{\b ()

}syntax.) Otherwise if {\i name }refers to a file, the file is read

in its entirety and the commands are executed in the current shell environment.

The search path specified by {\b{\fs22 PATH }}is used to

find the directory containing the file. If any arguments {\i arg }are given,

they become the positional parameters while processing the {\b . }command

and the original positional parameters are restored upon completion. Otherwise

the positional parameters are unchanged. The exit status is the exit status

of the last command executed. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7\'a7 {\b alias} [\~{\b\'2d ptx}

\~] [\~{\i name}[\~{\b =}{\i value\~}\~]\~].\~.\~.

\tab{\b alias }with no arguments prints the list of aliases in the

form {\i name=value }on standard output. The {\b\'2d p }option

causes the word {\b alias }to be inserted before each one. When

one or more arguments are given, an {\i alias }is defined for each {\i name

}whose {\i value }is given. A trailing space in {\i value }causes the

next word to be checked for alias substitution. The obsolete {\b\'2d t

}option is used to set and list tracked aliases. The value of a tracked

alias is the full pathname corresponding to the given {\i name}. The value

becomes undefined when the value of {\fs22{\b PATH }}is

reset but the alias remains tracked. Without the {\b\'2d t }option,

for each {\i name }in the argument list for which no {\i value }is given,

the name and value of the alias is printed. The obsolete {\b\'2d x

}option has no effect. The exit status is non-zero if a {\i name }is

given, but no value, and no alias has been defined for the {\i name\~}.

{\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 bg} [\~{\i job\~}.\~.\~. \~] \tab This

command is only on systems that support job control. Puts each specified

{\i job }into the background. The current job is put in the background

if {\i job }is not specified. See {\i Jobs }for a description of the format

of {\i job}. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b break} [\~{\i n\~}\~]

\tab Exit from the enclosing {\b for\~}, {\b while\~},

{\b until\~}, or {\b select }loop, if any. If {\i n

}is specified, then break {\i n }levels. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 builtin} [\~{\b\'2d ds}

\~] [\~{\b\'2d f} {\i file\~}\~][\~{\i name\~}.\~.\~.\~]

\tab If {\i name }is not specified, and no {\b\'2d f }option

is specified, the built-ins are printed on standard output. The {\b\'2d s

}option prints only the special built-ins. Otherwise, each {\i name

}represents the pathname whose basename is the name of the built-in. The

entry point function name is determined by prepending {\b b_ }to

the built-in name. Special built-ins cannot be bound to a pathname or deleted.

The {\b\'2d d }option deletes each of the given built-ins.

On systems that support dynamic loading, the {\b\'2d f }option

names a shared library containing the code for built-ins. Once a library

is loaded, its symbols become available for subsequent invocations of {\b builtin}.

Multiple libraries can be specified with separate invocations of the {\b builtin

}command. Libraries are searched in the reverse order in which they

are specified. When a library is loaded, it looks for a function in the

library whose name is {\b lib_init() }and invokes this function

with an argument of {\b 0}. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 cd} [\~{\b\'2d LP}

\~] [\~{\i arg\~}\~] \tab{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 cd} [\~{\b\'2d LP}

\~] {\i old\~}{\i new\~}\tab This command can be in either of

two forms. In the first form it changes the current directory to {\i arg}.

If {\i arg }is {\b\'2d }the directory is changed to the previous

directory. The shell variable {\b{\fs22 HOME }}is the default

{\i arg}. The variable {\fs22{\b PWD }}is set to the current

directory. The shell variable {\b{\fs22 CDPATH }}defines

the search path for the directory containing {\i arg}. Alternative directory

names are separated by a colon ({\b :}). The default path is {\b< null>

}(specifying the current directory). Note that the current directory

is specified by a null path name, which can appear immediately after the

equal sign or between the colon delimiters anywhere else in the path list.

If {\i arg }begins with a {\b /} then the search path is not used.

Otherwise, each directory in the path is searched for {\i arg}. \par\pard\qc\li1120\tx1120\tx20000 The second

form of {\b cd }substitutes the string {\i new }for the string

{\i old }in the current directory name, {\fs22{\b PWD}, }and

tries to change to this new directory. \par\pard\qc\li1120\tx1120\tx20000 By default, symbolic link names

are treated literally when finding the directory name. This is equivalent

to the {\b\'2d L }option. The {\b\'2d P }option

causes symbolic links to be resolved when determining the directory. The

last instance of {\b\'2d L }or {\b\'2d P }on the

command line determines which method is used. \par\pard\qc\li1120\tx1120\tx20000 The {\b cd }command

may not be executed by {\b rsh\~. }{\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 command}

[\~{\b\'2d pvV} \~] {\i name\~}[\~{\i arg\~}.\~.\~.\~]

\tab Without the {\b\'2d v }or {\b\'2d V }options,

{\b command }executes {\i name }with the arguments given by {\i arg}.

The {\b\'2d p }option causes a default path to be searched

rather than the one defined by the value of {\fs22{\b PATH}.

}Functions will not be searched for when finding {\i name}. In addition,

if {\i name }refers to a special built-in, none of the special properties

associated with the leading daggers will be honored. (For example, the predefined

alias {\b redirect='command exec' }prevents a script from terminating

when an invalid redirection is given.) With the {\b\'2d v }option,

{\b command }is equivalent to the built-in {\b whence }command

described below. The {\b\'2d V }option causes {\b command

}to act like {\b whence \'2dv}. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b continue}

[\~{\i n\~}\~] \tab Resume the next iteration of the enclosing

{\b for\~}, {\b while\~}, {\b until\~},

or {\b select }loop. If {\i n }is specified, then resume at the

{\i n}-th enclosing loop. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 disown} [\~{\i job\~}.\~.\~.

\~] \tab Causes the shell not to send a HUP signal to each given {\i job},

or all active jobs if {\i job }is omitted, when a login shell terminates.

{\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 echo} [\~{\i arg\~}.\~.\~. \~] \tab When

the first {\i arg }does not begin with a \'2d, and none of the arguments

contain a \'5c, then {\b echo }prints each of its arguments

separated by a space and terminated by a new-line. Otherwise, the behavior

of {\b echo }is system dependent and {\b print }or {\b printf

}described below should be used. See {\i echo}(1) for usage and description.

\par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b eval} [\~{\i arg\~}.\~.\~. \~]

\tab The arguments are read as input to the shell and the resulting command(s)

executed. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b exec} [\~{\b\'2d c}

\~] [\~{\b\'2d a} {\i name\~}\~][\~{\i arg\~}.\~.\~.\~]

\tab If {\i arg }is given, the command specified by the arguments is executed

in place of this shell without creating a new process. The {\b\'2d c

}option causes the environment to be cleared before applying variable

assignments associated with the {\b exec }invocation. The {\b\'2d a

}option causes {\i name }rather than the first {\i arg}, to become

{\b argv[0] }for the new process. Input/output arguments may appear

and affect the current process. If {\i arg }is not given, the effect of

this command is to modify file descriptors as prescribed by the input/output

redirection list. In this case, any file descriptor numbers greater than

2 that are opened with this mechanism are closed when invoking another program.

\par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b#{\footnote HTML2RTF.exit} exit}[\~{\i n\~}\~] \tab Causes

the shell to exit with the exit status specified by {\i n}. The value will

be the least significant 8 bits of the specified status. If {\i n }is omitted,

then the exit status is that of the last command executed. An end-of-file

will also cause the shell to exit except for a shell which has the {\b ignoreeof

}option (see {\uldb set}{\v HTML2RTF.set}{\*\comment{\b set }}below) turned on. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7\'a7

{\b export} [\~{\b\'2d p} \~] [\~{\i name\~}[\~{\b =}{\i value\~}\~]

\~].\~.\~. \tab If {\i name }is not given, the names and values

of each variable with the export attribute are printed with the values quoted

in a manner that allows them to be re-input. The {\b\'2d p }option

causes the word {\b export }to be inserted before each one. Otherwise,

the given {\i name}s are marked for automatic export to the {\i environment

}of subsequently-executed commands. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 false} \tab Does nothing,

and exits 1. Used with {\b until }for infinite loops. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 fg}

[\~{\i job\~}.\~.\~. \~] \tab This command is only on

systems that support job control. Each {\i job }specified is brought to

the foreground and waited for in the specified order. Otherwise, the current

job is brought into the foreground. See {\i Jobs }for a description of

the format of {\i job}. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 getconf} [\~{\i name\~}[\~{\i pathname\~}\~]

\~] \tab Prints the current value of the configuration parameter given

by {\i name}. The configuration parameters are defined by the IEEE POSIX

1003.1 and IEEE POSIX 1003.2 standards. (See {\i pathconf}(2) and {\i sysconf}(2).)

The {\i pathname }argument is required for parameters whose value depends

on the location in the file system. If no arguments are given, {\b getconf

}prints the names and values of the current configuration parameters.

The pathname {\b / }is used for each of the parameters that requires

{\i pathname}. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 getopts} [\~{\b\~ -a} {\i name\~}\~]

{\i optstring vname\~}[\~{\i arg\~}.\~.\~.\~]

\tab Checks {\i arg }for legal options. If {\i arg }is omitted, the positional

parameters are used. An option argument begins with a {\b + }or

a {\b\'2d}. An option not beginning with {\b + }or

{\b\'2d }or the argument {\b\'2d\~\'2d }ends

the options. {\i optstring }contains the letters that {\b getopts }recognizes.

If a letter is followed by a {\b :}, that option is expected to

have an argument. The options can be separated from the argument by blanks.

The option {\b\'2d ? }causes {\b getopts }to generate

a usage message on standard error. The {\b\'2d a }argument

can be used to specify the name to use for the usage message, which defaults

to {\b $0}. {\b\par\pard\qc\li1120\tx1120\tx20000 getopts }places the next option letter

it finds inside variable {\i vname }each time it is invoked. The option

letter will be prepended with a {\b + }when {\i arg }begins with

a {\b +}. The index of the next {\i arg }is stored in {\fs22{\b OPTIND}.

}The option argument, if any, gets stored in {\fs22{\b OPTARG}.

}\par\pard\qc\li1120\tx1120\tx20000 A leading {\b : }in {\i optstring }causes {\b getopts

}to store the letter of an invalid option in {\fs22{\b OPTARG},

}and to set {\i vname }to {\b ? }for an unknown option and

to {\b : }when a required option is missing. Otherwise, {\b getopts

}prints an error message. The exit status is non-zero when there are

no more options. \par\pard\qc\li1120\tx1120\tx20000 There is no way to specify any of the options {\b :},

{\b +}, {\b\'2d}, {\b ?}, {\b [},

and {\b ]}. The option {\b # }can only be specified as

the first option. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 hist} [\~{\b\'2d e} {\i ename\~}\~\~]

[\~{\b\'2d nlr\~}\~][\~{\i first\~}[\~{\i last\~}\~]\~]

\tab{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 hist \'2ds }[\~{\i old}{\b =}{\i new\~}\~]

[\~{\i command\~}\~] \tab In the first form, a range of commands

from {\i first }to {\i last }is selected from the last {\fs22{\b HISTSIZE

}}commands that were typed at the terminal. The arguments {\i first

}and {\i last }may be specified as a number or as a string. A string

is used to locate the most recent command starting with the given string.

A negative number is used as an offset to the current command number. If

the {\b\'2d l }option is selected, the commands are listed

on standard output. Otherwise, the editor program {\i ename }is invoked

on a file containing these keyboard commands. If {\i ename }is not supplied,

then the value of the variable {\fs22{\b HISTEDIT }}is

used. If {\fs22{\b HISTEDIT }}is not set, then {\fs22{\b FCEDIT

}}(default {\b /bin/ed\~}) is used as the editor.

When editing is complete, the edited command(s) is executed if the changes

have been saved. If {\i last }is not specified, then it will be set to

{\i first}. If {\i first }is not specified, the default is the previous

command for editing and \'2d16 for listing. The option {\b\'2d r

}reverses the order of the commands and the option {\b\'2d n

}suppresses command numbers when listing. In the second form, {\i command

}is interpreted as {\i first }described above and defaults to the last

command executed. The resulting command is executed after the optional substitution

{\i old\~}{\b =}{\i new\~}is performed. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 jobs}

[\~{\b\'2d lnp\~}\~] [\~{\i job\~}.\~.\~.

\~] \tab Lists information about each given job; or all active jobs if

{\i job }is omitted. The {\b\'2d l }option lists process ids

in addition to the normal information. The {\b\'2d n }option

only displays jobs that have stopped or exited since last notified. The

{\b\'2d p }option causes only the process group to be listed.

See {\i Jobs }for a description of the format of {\i job}. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 kill}

[\~{\b\'2d s} {\i signame\~}\~] {\i job\~}.\~.\~.

\tab{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 kill} [\~{\b\'2d n} {\i signum\~}\~]

{\i job\~}.\~.\~. \tab{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 kill} {\b\'2d l}

[\~{\i sig\~}.\~.\~. \~] \tab Sends either the TERM (terminate)

signal or the specified signal to the specified jobs or processes. Signals

are either given by number with the {\b\'2d n }option or by

name with the {\b\'2d s }option (as given in {\b< signal.h>},

stripped of the prefix ``SIG'' with the exception that SIGCLD is named CHLD).

For backward compatibility, the {\b n }and {\b s }can

be omitted and the number or name placed immediately after the {\b\'2d}.

If the signal being sent is TERM (terminate) or HUP (hangup), then the job

or process will be sent a CONT (continue) signal if it is stopped. The argument

{\i job }can be the process id of a process that is not a member of one

of the active jobs. See {\i Jobs }for a description of the format of {\i job}.

In the third form, {\b kill \'2dl}, if {\i sig }is not specified,

the signal names are listed. Otherwise, for each {\i sig }that is a name,

the corresponding signal number is listed. For each {\i sig }that is a

number, the signal name corresponding to the least significant 8 bits of

{\i sig }is listed. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 let} {\i arg\~}.\~.\~.

\tab Each {\i arg }is a separate {\i arithmetic expression }to be evaluated.

See {\i Arithmetic Evaluation }above, for a description of arithmetic expression

evaluation. \par\pard\qc\li1120\tx1120\tx20000 The exit status is 0 if the value of the last expression is

non-zero, and 1 otherwise. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b newgrp} [\~{\i arg\~}.\~.\~.

\~] \tab Equivalent to {\b exec /bin/newgrp}{\i arg\~}.\~.\~.\~.

{\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 print} [\~{\b\'2d Rnprs\~}\~] [\~{\b\'2d u}

{\i unit\~}\~] [\~{\b\'2d f}{\i format\~}\~][\~{\i arg\~}.\~.\~.\~]

\tab With no options or with option {\b\'2d }or {\b\'2d\~\'2d},

each {\i arg }is printed on standard output. The {\b\'2d f }option

causes the arguments to be printed as described by {\b printf}.

In this case, any {\b n}, {\b r}, {\b R }options

are ignored. Otherwise, unless the {\b\'2d R }or {\b\'2d r},

are specified, the following escape conventions will be applied: {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'5c a

}\tab The alert character (ascii {\b 07}). {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'5c b

}\tab The backspace character (ascii {\b 010}). {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'5c c

}\tab Causes {\b print }to end without processing more arguments

and not adding a new-line. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'5c f }\tab The formfeed character

(ascii {\b 014}). {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'5c n }\tab The new-line character

(ascii {\b 012}). {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'5c r }\tab The carriage return

character (ascii {\b 015}). {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'5c t }\tab The tab

character (ascii {\b 011}). {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'5c v }\tab The vertical

tab character (ascii {\b 013}). {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'5c E }\tab The

escape character (ascii {\b 033}). {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'5c\'5c }\tab The

backslash character \'5c. \par\pard\qc\fi-560\li1400\tx1400\tx20000{\b\'5c 0}{\i x }\tab The character

defined by the 1, 2, or 3-digit octal string given by {\i x}. \par\pard\qc\li1120\tx1120\tx20000 The

{\b\'2d R }option will print all subsequent arguments and options

other than {\b\'2d n}. The {\b\'2d p }option causes

the arguments to be written onto the pipe of the process spawned with {\b |&

}instead of standard output. The {\b\'2d s }option causes

the arguments to be written onto the history file instead of standard output.

The {\b\'2d u }option can be used to specify a one digit file

descriptor unit number {\i unit }on which the output will be placed. The

default is 1. If the option {\b\'2d n }is used, no {\b new-line

}is added to the output. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 printf} {\i format\~}[\~{\i arg\~}.\~.\~.

\~] \tab The arguments {\i arg }are printed on standard output in accordance

with the ANSI-C formatting rules associated with the format string {\i format}.

If the number of arguments exceeds the number of format specifications,

the {\b format }string is reused to format remaining arguments.

The following extensions can also be used: \par\pard\qc\li1400\tx1400\tx20000\par\pard\qc\fi-560\li1400\tx1400\tx20000\'b7 \tab A {\b %b

}format can be used instead of {\b %s }to cause escape sequences

in the corresponding {\i arg }to be expanded as described in {\b print.

}\par\pard\qc\li1400\tx1400\tx20000\par\pard\qc\fi-560\li1400\tx1400\tx20000\'b7 \tab A {\b %P }format can be used instead of {\b %s

}to cause {\i arg }to be interpreted as an extended regular expression

and be printed as a shell pattern. \par\pard\qc\li1400\tx1400\tx20000\par\pard\qc\fi-560\li1400\tx1400\tx20000\'b7 \tab A {\b %q }format

can be used instead of {\b %s }to cause the resulting string to

be quoted in a manner than can be reinput to the shell. \par\pard\qc\li1400\tx1400\tx20000\par\pard\qc\fi-560\li1400\tx1400\tx20000\'b7 \tab The

precision field of the {\b %d }format can be followed by a {\b .

}and the output base. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 pwd} [\~{\b\'2d LP}

\~] \tab Outputs the value of the current working directory. The {\b\'2d L

}option is the default; it prints the logical name of the current

directory. If the {\b\'2d P }option is given, all symbolic

links are resolved from the name. The last instance of {\b\'2d L

}or {\b\'2d P }on the command line determines which method

is used. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 read} [\~{\b\'2d Aprs\~}\~]

[\~{\b\'2d d} {\i delim\~}\~] [\~{\b\'2d t}{\i timeout\~}\~][\~{\b\'2d u}{\i unit\~}\~][\~{\i vname}{\b ?}{\i prompt\~}{\b\~ ][\~}{\i vname\~}{\b .\~.\~.\~]

\tab}The shell input mechanism. One line is read and is broken up into

fields using the characters in {\b{\fs22 IFS }}as separators.

The escape character, {\b\'5c}, is used to remove any special

meaning for the next character and for line continuation. The {\b\'2d d

}option causes the read to continue to the first character of {\i delim

}rather than new-line. In raw mode, {\b\'2d r, }the {\b\'5c

}character is not treated specially. The first field is assigned to

the first {\i vname}, the second field to the second {\i vname}, etc.,

with leftover fields assigned to the last {\i vname}. The {\b\'2d A

}option causes the variable {\i vname }to be unset and each field

that is read to be stored in successive elements of the indexed array {\i vname.

}The {\b\'2d p }option causes the input line to be taken

from the input pipe of a process spawned by the shell using {\b |&}.

If the {\b\'2d s }option is present, the input will be saved

as a command in the history file. The option {\b\'2d u }can

be used to specify a one digit file descriptor unit {\i unit }to read from.

The file descriptor can be opened with the {\b exec }special built-in

command. The default value of unit {\i n }is 0. The option {\b\'2d t

}is used to specify a timeout in seconds when reading from a terminal

or pipe. If {\i vname }is omitted, then {\fs22{\b REPLY }}is

used as the default {\i vname}. An end-of-file with the {\b\'2d p

}option causes cleanup for this process so that another can be spawned.

If the first argument contains a {\b ?}, the remainder of this

word is used as a {\i prompt }on standard error when the shell is interactive.

The exit status is 0 unless an end-of-file is encountered or {\b read

}has timed out. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7\'a7 {\b readonly} [\~{\b\'2d p}

\~] [\~{\i vname}[\~{\b =}{\i value\~}\~]

\~].\~.\~. \tab If {\i vname }is not given, the names and values

of each variable with the readonly attribute is printed with the values

quoted in a manner that allows them to be re-inputted. The {\b\'2d p

}option causes the word {\b readonly }to be inserted before

each one. Otherwise, the given {\i vname}s are marked readonly and these

names cannot be changed by subsequent assignment. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b return}

[\~{\i n\~}\~] \tab Causes a shell {\i function }or {\b\~ .}

script to return to the invoking script with the exit status specified by

{\i n}. The value will be the least significant 8 bits of the specified

status. If {\i n }is omitted, then the return status is that of the last

command executed. If {\b return }is invoked while not in a {\i function

}or a {\b\~ .} script, then it behaves the same as {\b exit}.

\par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b#{\footnote HTML2RTF.set} set}[\~{\b\'b1 Cabefhkmnopstuvx}

\~] [\~{\b\'b1 o} [\~{\i option\~}\~]\~].\~.\~.[\~{\b\'b1 A}{\i vname\~}\~][\~{\i arg\~}.\~.\~.\~]

\tab The options for this command have meaning as follows: {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d A

}\tab Array assignment. Unset the variable {\i vname }and assign values

sequentially from the {\i arg }list. If {\b +A }is used, the variable

{\i vname }is not unset first. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d C }\tab Prevents redirection

{\b> }from truncating existing files. Files that are created

are opened with the O_EXCL mode. Requires {\b> | }to truncate

a file when turned on. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d a }\tab All subsequent variables

that are defined are automatically exported. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d b }\tab Prints

job completion messages as soon as a background job changes state rather

than waiting for the next prompt. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d e }\tab If a command

has a non-zero exit status, execute the {\fs22{\b ERR }}trap,

if set, and exit. This mode is disabled while reading profiles. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d f

}\tab Disables file name generation. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d h }\tab Each

command becomes a tracked alias when first encountered. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d k

}\tab (Obsolete). All variable assignment arguments are placed in the

environment for a command, not just those that precede the command name.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d m }\tab Background jobs will run in a separate process

group and a line will print upon completion. The exit status of background

jobs is reported in a completion message. On systems with job control, this

option is turned on automatically for interactive shells. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d n

}\tab Read commands and check them for syntax errors, but do not execute

them. Ignored for interactive shells. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d o }\tab The following

argument can be one of the following option names: {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 allexport

}\tab Same as {\b\'2d a}. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 errexit }\tab Same

as {\b\'2d e}. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 bgnice }\tab All background jobs

are run at a lower priority. This is the default mode. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 emacs }\tab Puts

you in an {\i emacs }style in-line editor for command entry. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 gmacs

}\tab Puts you in a {\i gmacs }style in-line editor for command entry.

{\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 ignoreeof }\tab The shell will not exit on end-of-file. The

command {\b exit }must be used. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 keyword }\tab Same

as {\b\'2d k}. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 markdirs }\tab All directory names

resulting from file name generation have a trailing {\b / }appended.

{\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 monitor }\tab Same as {\b\'2d m}. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 noclobber

}\tab Same as {\b\'2d C}. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 noexec }\tab Same

as {\b\'2d n}. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 noglob }\tab Same as {\b\'2d f}.

{\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 nolog }\tab Do not save function definitions in the history

file. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 notify }\tab Same as {\b\'2d b}. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 nounset

}\tab Same as {\b\'2d u}. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 privileged }\tab Same

as {\b\'2d p}. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 verbose }\tab Same as {\b\'2d v}.

{\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 trackall }\tab Same as {\b\'2d h}. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 vi

}\tab Puts you in insert mode of a {\i vi }style in-line editor until

you hit the escape character {\b 033}. This puts you in control

mode. A return sends the line. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 viraw }\tab Each character is

processed as it is typed in {\i vi }mode. {\b\line\par\pard\qc\fi-560\li1680\tx1680\tx20000 xtrace }\tab Same

as {\b\'2d x}. \par\pard\qc\fi-560\li1680\tx1680\tx20000 If no option name is supplied, then thecurrentoptionsettingsareprinted.

\tab{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d p }\tab Disables processing of the {\b{\fs22 $HOME}/.profile

}file and uses the file {\b /etc/suid_profile }instead of

the {\fs22{\b ENV }}file. This mode is on whenever the

effective uid (gid) is not equal to the real uid (gid). Turning this off

causes the effective uid and gid to be set to the real uid and gid. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d s

}\tab Sort the positional parameters lexicographically. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d t

}\tab (Obsolete). Exit after reading and executing one command. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d u

}\tab Treat unset parameters as an error when substituting. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d v

}\tab Print shell input lines as they are read. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d x }\tab Print

commands and their arguments as they are executed. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d\~\'2d

}\tab Do not change any of the options; useful in setting {\b $1

}to a value beginning with {\b\'2d}. If no arguments

follow this option then the positional parameters are unset. \par\pard\qc\li1120\tx1120\tx20000 As an

obsolete feature, if the first {\i arg }is {\b\'2d }then the

{\b\'2d x }and {\b\'2d v }options are turned off

and the next {\i arg }is treated as the first argument. Using {\b +

}rather than {\b\'2d }causes these options to be turned

off. These options can also be used upon invocation of the shell. The current

set of options may be found in {\b $\'2d}. Unless {\b\'2d A

}is specified, the remaining arguments are positional parameters and

are assigned, in order, to {\b $1 }{\b $2 }.\~.\~.\~.

If no arguments are given, then the names and values of all variables are

printed on the standard output. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b shift} [\~{\i n\~}\~]

\tab The positional parameters from {\b $}{\i n}{\b +1}

.\~.\~. are renamed {\b $1 }.\~.\~.\~, default

{\i n }is 1. The parameter {\i n }can be any arithmetic expression that

evaluates to a non-negative number less than or equal to {\b $#}.

{\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 sleep} {\i seconds\~}\tab Suspends execution for the

number of decimal seconds or fractions of a second given by {\i seconds}.

\par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b trap'} [\~{\b\'2d p} \~] [\~{\i action\~}\~][\~{\i sig\~}\~].\~.\~.

\tab The {\b\'2d p }option causes the trap action associated

with each trap as specified by the arguments to be printed with appropriate

quoting. Otherwise, {\i action }will be processed as if it were an argument

to {\b eval }when the shell receives signal(s) {\i sig}. Each

{\i sig }can be given as a number or as the name of the signal. Trap commands

are executed in order of signal number. Any attempt to set a trap on a signal

that was ignored on entry to the current shell is ineffective. If {\i action

}is omitted and the first {\i sig }is a number, or if {\i action }is

{\b\'2d}, then the trap(s) for each {\i sig }are reset to

their original values. If {\i action }is the null string then this signal

is ignored by the shell and by the commands it invokes. If {\i sig }is

{\fs22{\b ERR }}then {\i action }will be executed whenever

a command has a non-zero exit status. If {\i sig }is {\fs22{\b DEBUG

}}then {\i action }will be executed before each command. If {\i sig

}is {\b 0 }or {\fs22{\b EXIT }}and the {\b trap

}statement is executed inside the body of a function, then the command

{\i action }is executed after the function completes. If {\i sig }is {\b 0

}or {\fs22{\b EXIT }}for a {\b trap }set

outside any function then the command {\i action }is executed on exit from

the shell. If {\i sig }is {\fs22{\b KEYBD}, }then {\i action

}will be executed whenever a key is read while in {\b emacs},

{\b gmacs}, or {\b vi }mode. The {\b trap }command

with no arguments prints a list of commands associated with each signal

number. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 true} \tab Does nothing, and exits 0. Used with {\b while

}for infinite loops. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7\'a7 {\b typeset} [\~{\b\'b1 AHflnprtux\~}\~]

[\~{\b\'b1 EFLRZi[\~}{\i n\~}{\b\~ ] \~][\~}{\i vname\~}{\b [\~=}{\i value\~}{\b\~ ]\~\~].\~.\~.

\tab}Sets attributes and values for shell variables and functions. When

invoked inside a function, a new instance of the variable {\i vname }is

created. The variable's value and type are restored when the function completes.

The following list of attributes may be specified: {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d A

}\tab Declares {\i vname }to be an associative array. Subscripts are

strings rather than arithmetic expressions. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d E }\tab Declares

{\i vname }to be a double precision floating point number. If {\i n }is

non-zero, it defines the number of significant figures that are used when

expanding {\i vname}. Otherwise, ten significant figures will be used.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d F }\tab Declares {\i vname }to be a double precision

floating point number. If {\i n }is non-zero, it defines the number of

places after the decimal point that are used when expanding {\i vname}.

Otherwise ten places after the decimal point will be used. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d H

}\tab This option provides UNIX to host-name file mapping on non-UNIX

machines. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d L }\tab Left justify and remove leading blanks

from {\i value}. If {\i n }is non-zero, it defines the width of the field,

otherwise it is determined by the width of the value of first assignment.

When the variable is assigned to, it is filled on the right with blanks

or truncated, if necessary, to fit into the field. The {\b\'2d R

}option is turned off. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d R }\tab Right justify

and fill with leading blanks. If {\i n }is non-zero, it defines the width

of the field, otherwise it is determined by the width of the value of first

assignment. The field is left filled with blanks or truncated from the end

if the variable is reassigned. The {\b\'2d L }option is turned

off. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d Z }\tab Right justify and fill with leading zeros

if the first non-blank character is a digit and the {\b\'2d L }option

has not been set. Remove leading zeros if the {\b\'2d L }option

is also set. If {\i n }is non-zero, it defines the width of the field,

otherwise it is determined by the width of the value of first assignment.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d f }\tab The names refer to function names rather than

variable names. No assignments can be made and the only other valid options

are {\b\'2d t}, {\b\'2d u }and {\b\'2d x}.

The {\b\'2d t }option turns on execution tracing for this function.

The {\b\'2d u }option causes this function to be marked undefined.

The {\fs22{\b FPATH }}variable will be searched to find

the function definition when the function is referenced. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d i

}\tab Declares {\i vname }to be represented internally as integer.

The right hand side of an assignment is evaluated as an arithmetic expression

when assigning to an integer. If {\i n }is non-zero, it defines the output

arithmetic base, otherwise the output base will be ten. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d l

}\tab All upper-case characters are converted to lower-case. The upper-case

option, {\b\'2d u}, is turned off. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d n }\tab Declares

{\i vname }to be a reference to the variable whose name is defined by the

value of variable {\i vname}. This is usually used to reference a variable

inside a function whose name has been passed as an argument. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d r

}\tab The given {\i vname}s are marked readonly and these names cannot

be changed by subsequent assignment. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d t }\tab Tags the

variables. Tags are user definable and have no special meaning to the shell.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d u }\tab All lower-case characters are converted to

upper-case. The lower-case option, {\b\'2d l}, is turned off.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d x }\tab The given {\i vname}s are marked for automatic

export to the {\i environment }of subsequently-executed commands. Variables

whose names contain a {\b{\fs26 .}} cannot be exported.

\par\pard\qc\li1120\tx1120\tx20000 The {\b\'2d i }attribute cannot be specified along with

{\b\'2d R}, {\b\'2d L}, {\b\'2d Z},

or {\b\'2d f}. \par\pard\qc\li1120\tx1120\tx20000 Using {\b + }rather than {\b\'2d

}causes these options to be turned off. If no {\i vname }arguments

are given, a list of {\i vnames }(and optionally the {\i values\~})

of the {\i variables }is printed. (Using {\b + }rather than {\b\'2d

}keeps the values from being printed.) The {\b\'2d p }option

causes {\b typeset }followed by the option letters to be printed

before each name rather than the names of the options. If any option other

than {\b\'2d p }is given, only those variables which have all

of the given options are printed. Otherwise, the {\i vname}s and {\i attributes

}of all {\i variables }are printed. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 ulimit} [\~{\b\'2d HSacdfmnpstv}

\~] [\~{\i limit\~}\~] \tab Set or display a resource limit.

The available resource limits are listed below. Many systems do not support

one or more of these limits. The limit for a specified resource is set when

{\i limit }is specified. The value of {\i limit }can be a number in the

unit specified below with each resource, or the value {\b unlimited}.

The {\b\'2d H }and {\b\'2d S }options specify

whether the hard limit or the soft limit for the given resource is set.

A hard limit cannot be increased once it is set. A soft limit can be increased

up to the value of the hard limit. If neither the {\b H }nor {\b S

}options is specified, the limit applies to both. The current resource

limit is printed when {\i limit }is omitted. In this case, the soft limit

is printed unless {\b H }is specified. When more than one resource

is specified, then the limit name and unit is printed before the value.

{\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d a }\tab Lists all of the current resource

limits. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d c }\tab The number of 512-byte blocks on the

size of core dumps. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d d }\tab The number of K-bytes on

the size of the data area. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d f }\tab The number of 512-byte

blocks on files that can be written by the current process or by child processes

(files of any size may be read). {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d m }\tab The number

of K-bytes on the size of physical memory. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d n }\tab The

number of file descriptors plus 1. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d p }\tab The number

of 512-byte blocks for pipe buffering. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d s }\tab The

number of K-bytes on the size of the stack area. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d t }\tab The

number of CPU seconds to be used by each process. {\b\line\par\pard\qc\fi-560\li1400\tx1400\tx20000\'2d v }\tab The

number of K-bytes for virtual memory. \par\pard\qc\li1120\tx1120\tx20000 If no option is given, {\b\'2d f

}is assumed. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 umask} [\~{\b\'2d S}

\~] [\~{\i mask\~}\~] \tab The user file-creation mask is

set to {\i mask }(see {\i umask}(2)). {\i mask }can either

be an octal number or a symbolic value as described in {\i chmod}(1). If

a symbolic value is given, the new umask value is the complement of the

result of applying {\i mask }to the complement of the previous umask value.

If {\i mask }is omitted, the current value of the mask is printed. The

{\b\'2d S }option causes the mode to be printed as a symbolic

value. Otherwise, the mask is printed in octal. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7 {\b unalias}

[\~{\b\'2d a} \~] {\i name\~}.\~.\~. \tab The

aliases given by the list of {\i name}s are removed from the alias list.

The {\b\'2d a }option causes all the aliases to be unset. \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000\'a7{\b unset}

[\~{\b\'2d fnv} \~] {\i vname\~}.\~.\~.

\tab The variables given by the list of {\i vname}s are unassigned, i.e.,

their values and attributes are erased. Readonly variables cannot be unset.

If the {\b\'2d f }option is set, then the names refer to {\i function

}names. If the {\b\'2d v }option is set, then the names refer

to {\i variable }names. The {\b\'2d f }option overrides {\b\'2d v}.

If {\b\'2d n }is set and {\i name }is a name reference, then

{\i name }will be unset rather than the variable that it references. The

default is equivalent to {\b\'2d v}. Unsetting {\fs22{\b LINENO},

}{\fs22{\b MAILCHECK}, }{\fs22{\b OPTARG},

}{\fs22{\b OPTIND}, }{\fs22{\b RANDOM},

}{\fs22{\b SECONDS}, }{\fs22{\b TMOUT},

}and {\fs22{\b _ }}removes their special meaning even

if they are subsequently assigned to. {\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 wait} [\~{\i job\~}.\~.\~.

\~] \tab Wait for the specified {\i job }and report its termination status.

If {\i job }is not given, then all currently active child processes are

waited for. The exit status from this command is that of the last process

waited for. See {\i Jobs }for a description of the format of {\i job}.

{\b\par\pard\qc\li1120\tx1120\tx20000\line\par\pard\qc\fi-560\li1120\tx1120\tx20000 whence} [\~{\b\'2d afpv} \~] {\i name\~}.\~.\~.

\tab For each {\i name}, indicate how it would be interpreted if used as

a command name. \par\pard\qc\li1120\tx1120\tx20000 The {\b\'2d v }option produces a more verbose

report. The {\b\'2d f }options skips the search for functions.

The {\b\'2d p }option does a path search for {\i name }even

if name is an alias, a function, or a reserved word. The {\b\'2d a

}option is similar to the {\b\'2d v }option but causes

all interpretations of the given name to be reported. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Invocation} Invocation.

\~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}If the shell is invoked

by {\i exec}(2), and the first character of argument zero ({\b $0})

is {\b\'2d}, then the shell is assumed to be a {\i login }shell

and commands are read from {\b /etc/profile }and then from either

{\b .profile }in the current directory or {\b{\fs22 $HOME}/.profile},

if either file exists. Next, for interactive shells, commands are read from

the file named by performing parameter expansion, command substitution,

and arithmetic substitution on the value of the environment variable {\fs22{\b ENV

}}if the file exists. If the {\b\'2d s }option is

not present and {\i arg }is, then a path search is performed on the first

{\i arg }to determine the name of the script to execute. The script {\i arg

}must have read permission and any {\i setuid }and {\i setgid }settings

will be ignored. If the script is not found on the path, {\i arg }is processed

as if it named a built-in command or function. Commands are then read as

described below; the following options are interpreted by the shell when

it is invoked: \par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000{\b\'2d c }\tab If the {\b\'2d c

}option is present, then commands are read from the first {\i arg}.

Any remaining arguments become positional parameters starting at {\b 0}.

{\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d s }\tab If the {\b\'2d s }option is present

or if no arguments remain, then commands are read from the standard input.

Shell output, except for the output of the {\i special builtin-in commands

}listed above, is written to file descriptor 2. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d i }\tab If

the {\b\'2d i }option is present or if the shell input and

output are attached to a terminal (as told by {\i tcgetattr}(2)), then

this shell is {\i interactive}. In this case {\fs22 TERM} is ignored

(so that {\b kill 0} does not kill an interactive shell) and {\fs22 INTR}

is caught and ignored (so that {\b wait }is interruptible). In

all cases, {\fs22 QUIT} is ignored by the shell. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d r

}\tab If the {\b\'2d r }option is present, the shell is

a restricted shell. {\b\line\par\pard\qc\fi-560\li1120\tx1120\tx20000\'2d D }\tab A list of all double quoted

strings that are preceded by a {\b $ }will be printed on standard

output and the shell will exit. This set of strings will be subject to language

translation when the locale is not C or POSIX. No commands will be executed.

\par\pard\qc\li1120\tx1120\tx20000\par\pard\qc\fi-560\li1120\tx1120\tx20000{\b\'2d I}{\i filename\~}\tab The {\b\'2d R }{\i filename

}option is used to generate a cross reference database that can be used

by a separate utility to find definitions and references for variables and

commands. \par\pard\qc\li840\tx840\tx20000 The remaining options and arguments are described under the

{\b set }command above. An optional {\b\'2d }as the

first argument is ignored. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.Rsh.Only} Rsh \~Only.

\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}{\i Rsh }is used to set up login

names and execution environments whose capabilities are more controlled

than those of the standard shell. The actions of {\b rsh }are identical

to those of {\b sh\~}, except that the following are disallowed:

\line changing directory (see {\i cd}(1)), \line setting

or unsetting the value or attributes of {\fs22{\b SHELL}, }{\fs22{\b ENV},

}or {\fs22{\b PATH}}{\fs20 0, }\line specifying

path or command names containing {\b /}, \line redirecting output

({\b>}, {\b> |}, {\b<>}, and {\b>>}).

\line adding or deleting built-in commands. \par\pard\qc\li840\tx840\tx20000 The restrictions above are

enforced after {\b .profile} and the {\fs22{\b ENV }}files

are interpreted. \par\pard\qc\li840\tx840\tx20000 When a command to be executed is found to be a shell

procedure, {\b rsh }invokes {\i sh\~}to execute it. Thus,

it is possible to provide to the end-user shell procedures that have access

to the full power of the standard shell, while imposing a limited menu of

commands; this scheme assumes that the end-user does not have write and

execute permissions in the same directory. \par\pard\qc\li840\tx840\tx20000 The net effect of these rules

is that the writer of the {\b .profile }has complete control over

user actions, by performing guaranteed setup actions and leaving the user

in an appropriate directory (probably {\i not }the login directory). \par\pard\qc\li840\tx840\tx20000 The

system administrator often sets up a directory of commands (e.g., {\b /usr/rbin})

that can be safely invoked by {\b rsh}. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.EXIT.STATUS} EXIT

\~STATUS \~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}Errors detected

by the shell, such as syntax errors, cause the shell to return a non-zero

exit status. Otherwise, the shell returns the exit status of the last command

executed (see also the {\uldb exit}{\v HTML2RTF.exit}{\*\comment{\b exit }}command above). If

the shell is being used non-interactively, then execution of the shell file

is abandoned. Run time errors detected by the shell are reported by printing

the command or function name and the error condition. If the line number

that the error occurred on is greater than one, then the line number is

also printed in square brackets ({\b []}) after the command or

function name. {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.FILES} FILES \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}/etc/passwd

\line /etc/profile \line /etc/suid_profile {\fs22\line $HOME}/{\b .}profile

\line /tmp/sh* \line /dev/null {\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.SEE.ALSO} SEE \~ALSO

\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}cat(1), cd(1), chmod(1), cut(1),

echo(1), emacs(1), env(1), gmacs(1), newgrp(1), stty(1), test(1), umask(1),

vi(1), dup(2), exec(2), fork(2), ioctl(2), lseek(2), paste(1), pathconf(2),

pipe(2), sysconf(2), umask(2), ulimit(2), wait(2), rand(3), a.out(5), profile(5),

environ(7). \par\pard\qc\li840\tx840\tx20000 Morris I. Bolsky and David G. Korn, {\i The New KornShell Command

and Programming Language}, Prentice Hall, 1995. {\i\par\pard\qc\li840\tx840\tx20000 POSIX \'2d Part

2: Shell and Utilities, }IEEE Std 1003.2-1992, ISO/IEC 9945-2, IEEE, 1993.

{\fs22{\b\par\pard\qc\li840\tx840\tx20000\line\par\pard\qc\fi-560\li840\tx840\tx20000{\b\fs30#{\footnote HTML2RTF.CAVEATS} CAVEATS \~\~\~\~\~}\par\pard\qc\li840\tx840\tx20000}}If

a command is executed, and then a command with the same name is installed

in a directory in the search path before the directory where the original

command was found, the shell will continue to {\i exec }the original command.

Use the {\b\'2d t }option of the {\b alias }command

to correct this situation. \par\pard\qc\li840\tx840\tx20000 Some very old shell scripts contain a {\b ^

}as a synonym for the pipe character {\b |}. \par\pard\qc\li840\tx840\tx20000 Using the

{\b hist }built-in command within a compound command will cause

the whole command to disappear from the history file. \par\pard\qc\li840\tx840\tx20000 The built-in command

{\b\~ .} {\i file\~}reads the whole file before any commands

are executed. Therefore, {\b alias }and {\b unalias }commands

in the file will not apply to any commands defined in the file. \par\pard\qc\li840\tx840\tx20000 Traps

are not processed while a job is waiting for a foreground process. Thus,

a trap on {\b CHLD }won't be executed until the foreground job

terminates. \par\pard\qc\li840\tx840\tx20000 It is a good idea to leave a space after the comma operator

in arithmetic expressions to prevent the comma from being interpreted as

the decimal point character in certain locales. {\brdrt\brdrsh\par}{\b\fs32\par\pard\qc\li0\tx0\tx20000\~ Sun

Release 4.0\~\~\~\~\~\~\~\~\~\~\~\~\~Last change:\~\~\~\~\~\~\~\~\~\~\~\~1b}

}

}