files.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1995 Sun Microsystems, Inc. All Rights Reserved
*
* module:
* files.c
*
* purpose:
* routines to examine and manipulate file names
*
* contents:
* qualify ... ensure that a name is fully qualified
* expand ... expand env variables within a string or file name
* noblanks .. ensure that a name contains no embdded unescaped blanks
* wildcards . see whether or not a name contains wild cards
* prefix .... does one string begin with another
* suffix .... does one string end with another
* contains .. does one string contain another
*
* cannonize (static) ... compress redundant "." and ".." out of name
*
* notes:
* we are interested in embedded blanks because international
* character sets and non-unix file systems can both contain
* the byte 0x20. Thus, whenever we record a filename in
* file, we must be careful to escape any embedded blanks that
* cause trouble when we re-lex that file later.
*/
#ident "%W% %E% SMI"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include "filesync.h"
#include "messages.h"
/*
* routine:
* qualify
*
* purpose:
* to fully qualify a name
*
* parameters:
* name to be qualified
*
* returns:
* either original pointer or copy to a new (malloced) buffer
*
* notes:
* someday I may conclude that I should always make a copy
* so that the caller can know that it is safe to free the parm
*
* I thought about this and concluded that there is never a need
* to fully qualify a string containing variables. If the string
* came from the command line, the variables were already expanded
* and if it came from the rules data base it is required to already
* be fully qualified.
*/
char *
{
/* in the simple case, the parameter is already there */
if (*name == '/') {
return (name);
}
/* things that begin with variables get the benefit of the doubt */
if (*name == '$') {
return (name);
}
/* start with the current working directory */
}
/* make sure we have room for our file name */
}
/* append the specified file name to it */
/* filter out redundant dots */
/* and return a newly malloc'd copy */
}
/*
* routine:
* expand
*
* purpose:
* to expand variable names within a string
*
* parameters:
* string to be expanded. Variable references always begin
* with a $ and are delimited by parens or curleys.
*
* returns:
* either original pointer or a copy to a new (malloced) buffer
*
* notes:
* someday I may conclude that I should always make a copy
* so that the caller can know that it is safe to free the parm
*
* someday I may decide to support escape conventions for embedding
* $(){} in file names, but I suspec that day will never come.
*
* I thought about this and concluded there was no reason to
* fully qualify these names, because the only names that should
* and the shell should have handled those for me. Once something
* makes it into the database, it is expected to be fully qualified
* already.
*
* We are limited to producing strings of length MAX_PATH or less
* and variable names of length MAX_NAME or less. In practice,
* these limitations should not be a problem.
*/
char *
{ const char *s;
char *p, *v;
char delim;
/* first see if there are no variables to be bound */
for (s = name; *s && *s != '$'; s++);
if (*s == 0)
return (name);
/* move through the string, copying and expanding */
/* check for overflow */
}
/* normal characters, we just copy */
if (*s != '$') {
*p++ = *s;
continue;
}
/* figure out how the variable name is delimited */
delim = *++s;
if (delim == '(') {
delim = ')';
s++;
} else if (delim == '{') {
delim = '}';
s++;
} else
delim = 0;
/* copy the variable name up to the closing delimiter */
for (v = varbuf; *s; s++) {
if (isalnum(*s) || (*s == '_') ||
*v++ = *s;
else
break;
/* make sure we don't overflow var name buffer */
*v = 0;
}
}
*v = 0;
/* FIX THIS ... there must be a more elegant way */
/* we may have to back up because s will be bumped */
s--;
/* look up the variable */
if (v == 0 || *v == 0) {
return (0);
}
/* copy the variable into the buffer */
while (*v)
*p++ = *v++;
}
/* null terminate the copy */
*p = 0;
/* compress out any redundant dots and dot-dots */
/* and return a newly malloc'd copy */
}
/*
* routine:
* noblanks
*
* purpose:
* to ensure that a name contains no unescaped embedded blanks
*
* parameters:
* pointer to name
*
* returns:
* pointer to name or pointer to buffer containing escaped version of name
*
* notes:
* this routine can be called on full file names, and so can
* conceivably require an arbitrarily large buffer.
*/
const char *
{
const char *s;
char *p;
static char *namebuf = 0;
static int buflen = 0;
int l;
/* first see if there are no embedded blanks */
for (s = name; *s && *s != ' '; s++);
if (*s == 0)
return (name);
/* make sure we have a buffer large enough for the worst case */
/* quote the name, and copy it, escaping quotes */
p = namebuf;
*p++ = '"';
for (s = name; *s; s++) {
if (*s == '"' || *s == '\\')
*p++ = '\\';
*p++ = *s;
}
*p++ = '"';
*p = 0;
return (namebuf);
}
/*
* routine:
* lex
*
* purpose:
* my own version of strtok that handles quoting and escaping
*
* parameters:
* FILE structure for file to read (0 for same string, same file)
*
* returns:
* pointer to next token
*
* notes:
* this routine makes no changes to the string it is passed,
* copying tokens into a static buffer.
*
* this routine handles continuation lines after reading and
* before the lexing even starts. This limits continued lines
* to a length of MAX_LINE, but keeps everything else very simple.
* We also, therefore, limit tokens to a maximum length of MAX_LINE.
*/
int lex_linenum; /* line number in current input file */
char *
{ char c, delim;
char *p;
char *s;
static char *savep;
if (file) { /* read a new line */
/* read the next input line, with all continuations */
lex_linenum++;
/* go find the last character of the input line */
while (*s && s[1])
s++;
if (*s == '\n')
s--;
/* see whether or not we need a continuation */
if (s < inbuf || *s != '\\')
break;
continue;
}
if (savep == 0)
return (0);
s = inbuf;
} else { /* continue with old line */
if (savep == 0)
return (0);
s = savep;
}
savep = 0;
/* skip over leading white space */
while (isspace(*s))
s++;
if (*s == 0)
return (0);
/* see if this is a quoted string */
c = *s;
if (c == '\'' || c == '"') {
delim = c;
s++;
} else
delim = 0;
/* copy the token into the buffer */
for (p = namebuf; (c = *s) != 0; s++) {
/* literal escape */
if (c == '\\') {
s++;
*p++ = *s;
continue;
}
/* closing delimiter */
if (c == delim) {
s++;
break;
}
/* delimiting white space */
break;
/* ordinary characters */
*p++ = *s;
}
/* remember where we left off */
savep = *s ? s : 0;
/* null terminate and return the buffer */
*p = 0;
return (namebuf);
}
/*
* routine:
* wildcards
*
* purpose:
* determine whether or not there are any wild cards in a name
*
* parameters:
* name to be checked
*
* returns:
*
* notes:
* we use this to take shortcuts
*/
{ const char *s;
int literal = 0;
for (s = name; *s; s++)
if (literal)
switch (*s) {
case '\'': /* end of literal string */
literal = 0;
continue;
case '\\': /* escape next character */
s++;
continue;
}
else
switch (*s) {
case '\'': /* literal string */
literal = 1;
continue;
case '\\': /* escape next character */
s++;
continue;
case '*':
case '[':
case '{':
case '?':
/* any of these is a wild card */
return (TRUE);
}
return (FALSE);
}
/*
* routine:
* cannonize
*
* purpose:
* to compress redundant dots out of a path
*
* parameters:
* file name in an editable buffer
*
* returns:
* void
*
* notes:
* because we compress the string in place, there is no danger
* of our overflowing any fixed sized buffer.
*/
static void
{ char *s, *p;
/* leading dot-slashes */
for (s = name; *s; s++) {
/* interesting things happen after slashes */
if (*s != '/')
continue;
/* embedded dot-slashes */
while (s[1] == '.' && s[2] == '/')
/* embedded slash-dot-dot-slash */
/* scan backwards to eliminate last directory */
if (p < name)
p = name;
strcpy(p, &s[3]);
}
continue;
}
}
/*
* routine:
* prefix
*
* purpose:
* determine whether or not one string begins with another
*
* parameters:
* string to be tested
* suspected prefix
*
* returns:
* no 0
* yes pointer character after prefix
*/
const char *
prefix(const char *s, const char *p)
{
while (*p)
if (*p++ != *s++)
return (0);
return (s);
}
/*
* routine:
* suffix
*
* purpose:
* determine whether or not one string ends with another
*
* parameters:
* string to be tested
* suspected suffix
*
* returns:
*/
{ const char *s;
/* go to where the alleged suffix would start */
for (s = str; *s; s++);
if (s < str)
return (FALSE);
/* see if the string ends with the suffix */
while (*suf)
if (*suf++ != *s++)
return (FALSE);
return (TRUE);
}
/*
* routine:
* contains
*
* purpose:
* determine whether or not one string contains another
*
* parameters:
* string to be checked
* pattern we are seeking
*
* returns:
*/
{ const char *s, *p;
while (*str) {
if (p[1] == 0)
return (TRUE);
}
}
return (FALSE);
}