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mirror of https://git.FreeBSD.org/src.git synced 2024-12-29 12:03:03 +00:00
freebsd/lib/libc/gen/dirname.c
Rob Braun 5fb691beab Reduce libc.so's memory footprint by lazily allocating memory used internally
by basename() and dirname().
Reviewed by: eric
2002-12-21 07:12:35 +00:00

87 lines
2.6 KiB
C

/*
* Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``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 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.
*/
#if 0
#ifndef lint
static char rcsid[] = "$OpenBSD: dirname.c,v 1.4 1999/05/30 17:10:30 espie Exp $";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <errno.h>
#include <libgen.h>
#include <string.h>
#include <sys/param.h>
char *
dirname(path)
const char *path;
{
static char *bname = NULL;
const char *endp;
if (bname == NULL) {
bname = (char *)malloc(MAXPATHLEN);
if (bname == NULL)
return(NULL);
}
/* Empty or NULL string gets treated as "." */
if (path == NULL || *path == '\0') {
(void)strcpy(bname, ".");
return(bname);
}
/* Strip trailing slashes */
endp = path + strlen(path) - 1;
while (endp > path && *endp == '/')
endp--;
/* Find the start of the dir */
while (endp > path && *endp != '/')
endp--;
/* Either the dir is "/" or there are no slashes */
if (endp == path) {
(void)strcpy(bname, *endp == '/' ? "/" : ".");
return(bname);
} else {
do {
endp--;
} while (endp > path && *endp == '/');
}
if (endp - path + 2 > MAXPATHLEN) {
errno = ENAMETOOLONG;
return(NULL);
}
(void)strncpy(bname, path, endp - path + 1);
bname[endp - path + 1] = '\0';
return(bname);
}