File: [local] / src / usr.bin / which / which.c (download)
Revision 1.25, Thu Jan 14 22:02:13 2016 UTC (8 years, 4 months ago) by millert
Branch: MAIN
CVS Tags: OPENBSD_6_0_BASE, OPENBSD_6_0, OPENBSD_5_9_BASE, OPENBSD_5_9 Changes since 1.24: +6 -8 lines
Check the return value of snprintf() for potential overflow instead
of doing a manual check beforehand.
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/* $OpenBSD: which.c,v 1.25 2016/01/14 22:02:13 millert Exp $ */
/*
* Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <err.h>
#include <errno.h>
#include <locale.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#define PROG_WHICH 1
#define PROG_WHEREIS 2
extern char *__progname;
int findprog(char *, char *, int, int);
__dead void usage(void);
/*
* which(1) -- find an executable(s) in the user's path
* whereis(1) -- find an executable(s) in the default user path
*
* Return values:
* 0 - all executables found
* 1 - some found, some not
* 2 - none found
*/
int
main(int argc, char *argv[])
{
char *path;
size_t n;
int ch, allmatches = 0, notfound = 0, progmode = PROG_WHICH;
(void)setlocale(LC_ALL, "");
while ((ch = getopt(argc, argv, "a")) != -1)
switch (ch) {
case 'a':
allmatches = 1;
break;
default:
usage();
}
argc -= optind;
argv += optind;
if (argc == 0)
usage();
if (strcmp(__progname, "whereis") == 0) {
progmode = PROG_WHEREIS;
path = _PATH_STDPATH;
} else {
if ((path = getenv("PATH")) == NULL || *path == '\0')
path = _PATH_DEFPATH;
}
/* To make access(2) do what we want */
if (setgid(getegid()))
err(1, "Can't set gid to %u", getegid());
if (setuid(geteuid()))
err(1, "Can't set uid to %u", geteuid());
if (pledge("stdio rpath", NULL) == -1)
err(2, "pledge");
for (n = 0; n < argc; n++)
if (findprog(argv[n], path, progmode, allmatches) == 0)
notfound++;
exit((notfound == 0) ? 0 : ((notfound == argc) ? 2 : 1));
}
int
findprog(char *prog, char *path, int progmode, int allmatches)
{
char *p, filename[PATH_MAX];
int len, rval = 0;
struct stat sbuf;
char *pathcpy;
/* Special case if prog contains '/' */
if (strchr(prog, '/')) {
if ((stat(prog, &sbuf) == 0) && S_ISREG(sbuf.st_mode) &&
access(prog, X_OK) == 0) {
(void)puts(prog);
return (1);
} else {
warnx("%s: Command not found.", prog);
return (0);
}
}
if ((path = strdup(path)) == NULL)
err(1, "strdup");
pathcpy = path;
while ((p = strsep(&pathcpy, ":")) != NULL) {
if (*p == '\0')
p = ".";
len = strlen(p);
while (len > 0 && p[len-1] == '/')
p[--len] = '\0'; /* strip trailing '/' */
len = snprintf(filename, sizeof(filename), "%s/%s", p, prog);
if (len < 0 || len >= sizeof(filename)) {
warnc(ENAMETOOLONG, "%s/%s", p, prog);
free(path);
return (0);
}
if ((stat(filename, &sbuf) == 0) && S_ISREG(sbuf.st_mode) &&
access(filename, X_OK) == 0) {
(void)puts(filename);
rval = 1;
if (!allmatches) {
free(path);
return (rval);
}
}
}
(void)free(path);
/* whereis(1) is silent on failure. */
if (!rval && progmode != PROG_WHEREIS)
warnx("%s: Command not found.", prog);
return (rval);
}
__dead void
usage(void)
{
(void)fprintf(stderr, "usage: %s [-a] name ...\n", __progname);
exit(1);
}