.fp 5 CW

.de Af

.ds ;G \\*(;G\\f\\$1\\$3\\f\\$2

.if !\\$4 .Af \\$2 \\$1 "\\$4" "\\$5" "\\$6" "\\$7" "\\$8" "\\$9"

..

.de aF

.ie \\$3 .ft \\$1

.el \{\

.ds ;G \&

.nr ;G \\n(.f

.Af "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7" "\\$8" "\\$9"

\\*(;G

.ft \\n(;G \}

..

.de L

.aF 5 \\n(.f "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7"

..

.de LR

.aF 5 1 "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7"

..

.de RL

.aF 1 5 "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7"

..

.de EX \" start example

.ta 1i 2i 3i 4i 5i 6i

.PP

.RS

.PD 0

.ft 5

.nf

..

.de EE \" end example

.fi

.ft

.PD

.RE

.PP

..

.TH SPAWNVEG 3

.SH NAME

spawnveg \- process spawn with process group and session control

.SH SYNOPSIS

.L "#include <ast.h>"

.sp

.L "int spawnveg(const char* command, char** argv, char** envv, pid_t pgid);"

.SH DESCRIPTION

.L spwanveg

combines

.IR fork (2),

.IR exec (2),

.IR setpgid (2)

and

.IR setsid (2)

into a single call.

.PP

.LR command ,

.L argv

and

.L envv

are as in

.IR execve (2).

.L pgid

controls the new process group and session:

.TP

.L <0

The new process becomes a session leader.

is called in the child context.

.TP

.L 0

The new process is in the callers process group.

.TP

.L 1

The new process becomes a process group leader.

.TP

.L >1

The new process joins the process group

.IR pgid .

.SH COMMENTS

It is possible to code all process creation (except for

.IR vfork (2)

hack like in

.IR csh (1))

using

.LR spawnveg .

The

.IR proc (3)

routines and

.IR ksh (1)

do this on systems that don't support

.IR fork (2).

This makes porting to NT and Windows a snap: a simple

.IR iffe (1)

probe provides a

.L spawnveg

implementation using the NT or Windows process primitives.

.SH "SEE ALSO"

fork(2), exec(2), setpgid(2), setsid(2), spawnve(2)