freebsd-dev/usr.bin/cpio/pathmatch.c
2010-05-08 16:47:33 +00:00

256 lines
6.3 KiB
C

/*-
* Copyright (c) 2003-2007 Tim Kientzle
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "cpio_platform.h"
__FBSDID("$FreeBSD$");
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include "pathmatch.h"
/*
* Check whether a character 'c' is matched by a list specification [...]:
* * Leading '!' negates the class.
* * <char>-<char> is a range of characters
* * \<char> removes any special meaning for <char>
*
* Some interesting boundary cases:
* a-d-e is one range (a-d) followed by two single characters - and e.
* \a-\d is same as a-d
* a\-d is three single characters: a, d, -
* Trailing - is not special (so [a-] is two characters a and -).
* Initial - is not special ([a-] is same as [-a] is same as [\\-a])
* This function never sees a trailing \.
* [] always fails
* [!] always succeeds
*/
static int
pm_list(const char *start, const char *end, const char c, int flags)
{
const char *p = start;
char rangeStart = '\0', nextRangeStart;
int match = 1, nomatch = 0;
/* This will be used soon... */
(void)flags; /* UNUSED */
/* If this is a negated class, return success for nomatch. */
if (*p == '!' && p < end) {
match = 0;
nomatch = 1;
++p;
}
while (p < end) {
nextRangeStart = '\0';
switch (*p) {
case '-':
/* Trailing or initial '-' is not special. */
if ((rangeStart == '\0') || (p == end - 1)) {
if (*p == c)
return (match);
} else {
char rangeEnd = *++p;
if (rangeEnd == '\\')
rangeEnd = *++p;
if ((rangeStart <= c) && (c <= rangeEnd))
return (match);
}
break;
case '\\':
++p;
/* Fall through */
default:
if (*p == c)
return (match);
nextRangeStart = *p; /* Possible start of range. */
}
rangeStart = nextRangeStart;
++p;
}
return (nomatch);
}
/*
* If s is pointing to "./", ".//", "./././" or the like, skip it.
*/
static const char *
pm_slashskip(const char *s) {
while ((*s == '/')
|| (s[0] == '.' && s[1] == '/')
|| (s[0] == '.' && s[1] == '\0'))
++s;
return (s);
}
static int
pm(const char *p, const char *s, int flags)
{
const char *end;
/*
* Ignore leading './', './/', '././', etc.
*/
if (s[0] == '.' && s[1] == '/')
s = pm_slashskip(s + 1);
if (p[0] == '.' && p[1] == '/')
p = pm_slashskip(p + 1);
for (;;) {
switch (*p) {
case '\0':
if (s[0] == '/') {
if (flags & PATHMATCH_NO_ANCHOR_END)
return (1);
/* "dir" == "dir/" == "dir/." */
s = pm_slashskip(s);
}
return (*s == '\0');
case '?':
/* ? always succeds, unless we hit end of 's' */
if (*s == '\0')
return (0);
break;
case '*':
/* "*" == "**" == "***" ... */
while (*p == '*')
++p;
/* Trailing '*' always succeeds. */
if (*p == '\0')
return (1);
while (*s) {
if (pathmatch(p, s, flags))
return (1);
++s;
}
return (0);
case '[':
/*
* Find the end of the [...] character class,
* ignoring \] that might occur within the class.
*/
end = p + 1;
while (*end != '\0' && *end != ']') {
if (*end == '\\' && end[1] != '\0')
++end;
++end;
}
if (*end == ']') {
/* We found [...], try to match it. */
if (!pm_list(p + 1, end, *s, flags))
return (0);
p = end; /* Jump to trailing ']' char. */
break;
} else
/* No final ']', so just match '['. */
if (*p != *s)
return (0);
break;
case '\\':
/* Trailing '\\' matches itself. */
if (p[1] == '\0') {
if (*s != '\\')
return (0);
} else {
++p;
if (*p != *s)
return (0);
}
break;
case '/':
if (*s != '/' && *s != '\0')
return (0);
/* Note: pattern "/\./" won't match "/";
* pm_slashskip() correctly stops at backslash. */
p = pm_slashskip(p);
s = pm_slashskip(s);
if (*p == '\0' && (flags & PATHMATCH_NO_ANCHOR_END))
return (1);
--p; /* Counteract the increment below. */
--s;
break;
case '$':
/* '$' is special only at end of pattern and only
* if PATHMATCH_NO_ANCHOR_END is specified. */
if (p[1] == '\0' && (flags & PATHMATCH_NO_ANCHOR_END)){
/* "dir" == "dir/" == "dir/." */
return (*pm_slashskip(s) == '\0');
}
/* Otherwise, '$' is not special. */
/* FALL THROUGH */
default:
if (*p != *s)
return (0);
break;
}
++p;
++s;
}
}
/* Main entry point. */
int
pathmatch(const char *p, const char *s, int flags)
{
/* Empty pattern only matches the empty string. */
if (p == NULL || *p == '\0')
return (s == NULL || *s == '\0');
/* Leading '^' anchors the start of the pattern. */
if (*p == '^') {
++p;
flags &= ~PATHMATCH_NO_ANCHOR_START;
}
if (*p == '/' && *s != '/')
return (0);
/* Certain patterns and file names anchor implicitly. */
if (*p == '*' || *p == '/' || *p == '/') {
while (*p == '/')
++p;
while (*s == '/')
++s;
return (pm(p, s, flags));
}
/* If start is unanchored, try to match start of each path element. */
if (flags & PATHMATCH_NO_ANCHOR_START) {
for ( ; s != NULL; s = strchr(s, '/')) {
if (*s == '/')
s++;
if (pm(p, s, flags))
return (1);
}
return (0);
}
/* Default: Match from beginning. */
return (pm(p, s, flags));
}