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/**
* Copyright (c) 2000 Dan Papasian. 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 BY THE AUTHOR ``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.
*
* $FreeBSD$
*/
#include <sys/stat.h>
#include <sys/param.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
static void usage(void);
static int print_matches(char *, char *);
int silent;
int allpaths;
int
main(int argc, char **argv)
{
char *p, *path;
ssize_t pathlen;
int opt, status;
status = EXIT_SUCCESS;
/* If called without args, die silently to conform */
if (argc < 2)
exit(EXIT_FAILURE);
while ((opt = getopt(argc, argv, "as")) != -1) {
switch (opt) {
case 'a':
allpaths = 1;
break;
case 's':
silent = 1;
break;
default:
usage();
break;
}
}
argv += optind;
argc -= optind;
if ((p = getenv("PATH")) == NULL)
exit(EXIT_FAILURE);
pathlen = strlen(p) + 1;
path = malloc(pathlen);
if (path == NULL)
err(EXIT_FAILURE, NULL);
if (argc == 0)
status = EXIT_FAILURE;
while (argc > 0) {
memcpy(path, p, pathlen);
if (strlen(*argv) > FILENAME_MAX ||
print_matches(path, *argv) == -1)
status = EXIT_FAILURE;
argv++;
argc--;
}
exit(status);
}
static void
usage(void)
{
errx(EXIT_FAILURE, "usage: which [-as] program ...");
}
static int
is_there(char *candidate)
{
struct stat fin;
/* XXX work around access(2) false positives for superuser */
if (access(candidate, X_OK) == 0 &&
stat(candidate, &fin) == 0 &&
S_ISREG(fin.st_mode) &&
(getuid() != 0 ||
(fin.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0)) {
if (!silent)
printf("%s\n", candidate);
return (1);
}
return (0);
}
static int
print_matches(char *path, char *filename)
{
char candidate[PATH_MAX];
char *d;
int found;
if (*filename == '/')
return (is_there(filename) ? 0 : -1);
found = 0;
while ((d = strsep(&path, ":")) != NULL) {
if (snprintf(candidate, sizeof(candidate), "%s/%s", d,
filename) >= sizeof(candidate))
continue;
if (is_there(candidate)) {
found = 1;
if (!allpaths)
break;
}
}
return (found ? 0 : -1);
}
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