ossp-pkg/path/path_rel2abs.c
1.1.1.1
/*
* Copyright (c) 1997 Shigio Yamaguchi. All rights reserved.
* Copyright (c) 1999 Tama Communications Corporation. 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.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Tama Communications
* Corporation.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <errno.h>
#include <stdlib.h>
#include <string.h>
#include "path.h"
/*
* rel2abs: convert an relative path name into absolute.
*/
char *
path_rel2abs(
char *result,
size_t size,
const char *path,
const char *base)
{
const char *pp, *bp;
const char *endp;
char *rp;
int length;
/* endp points the last position which is safe in the result buffer. */
endp = result + size - 1;
if (*path == '/') {
if (strlen(path) >= size)
goto erange;
strcpy(result, path);
goto finish;
}
else if (*base != '/' || !size) {
errno = EINVAL;
return (NULL);
}
else if (size == 1) {
goto erange;
}
if (!strcmp(path, ".") || !strcmp(path, "./")) {
if (strlen(base) >= size)
goto erange;
strcpy(result, base);
/* rp points the last char. */
rp = result + strlen(base) - 1;
if (*rp == '/')
*rp = 0;
else
rp++;
/* rp point NULL char */
if (*++path == '/') {
/* Append '/' to the tail of path name. */
*rp++ = '/';
if (rp > endp)
goto erange;
*rp = 0;
}
goto finish;
}
bp = base + strlen(base);
if (*(bp - 1) == '/')
--bp;
/*
* up to root.
*/
for (pp = path; *pp && *pp == '.'; ) {
if (!strncmp(pp, "../", 3)) {
pp += 3;
while (bp > base && *--bp != '/')
;
}
else if (!strncmp(pp, "./", 2)) {
pp += 2;
}
else if (!strncmp(pp, "..\0", 3)) {
pp += 2;
while (bp > base && *--bp != '/')
;
}
else
break;
}
/*
* down to leaf.
*/
length = bp - base;
if (length >= size)
goto erange;
strncpy(result, base, length);
rp = result + length;
if (*pp || *(pp - 1) == '/' || length == 0)
*rp++ = '/';
if (rp + strlen(pp) > endp)
goto erange;
strcpy(rp, pp);
finish:
return result;
erange:
errno = ERANGE;
return (NULL);
}
