freebsd-src/usr.bin/which/which.c
Collin Funk 8268a31bcc which: Use size_t instead of ssize_t for pathlen
The "pathlen" variable is the return value of strlen(3) and is then
passed as an argument to malloc(3) and memcpy(3). The size_t type
matches the prototype for these functions. The size_t type is unsigned
so it can fit larger $PATH values than ssize_t. However, in practice
ssize_t should be larger enough so this change is just for clarity.

Signed-off-by: Collin Funk <collin.funk1@gmail.com>

MFC after:	1 week
Pull Request:	https://github.com/freebsd/freebsd-src/pull/1113
2024-04-05 14:30:31 -04:00

145 lines
3.4 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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.
*/
#include <sys/param.h>
#include <sys/stat.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 *);
static int silent;
static int allpaths;
int
main(int argc, char **argv)
{
char *p, *path;
size_t pathlen;
int opt, status;
status = EXIT_SUCCESS;
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 (argc == 0)
usage();
if ((p = getenv("PATH")) == NULL)
exit(EXIT_FAILURE);
pathlen = strlen(p) + 1;
path = malloc(pathlen);
if (path == NULL)
err(EXIT_FAILURE, NULL);
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)
{
(void)fprintf(stderr, "usage: which [-as] program ...\n");
exit(EXIT_FAILURE);
}
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];
const char *d;
int found;
if (strchr(filename, '/') != NULL)
return (is_there(filename) ? 0 : -1);
found = 0;
while ((d = strsep(&path, ":")) != NULL) {
if (*d == '\0')
d = ".";
if (snprintf(candidate, sizeof(candidate), "%s/%s", d,
filename) >= (int)sizeof(candidate))
continue;
if (is_there(candidate)) {
found = 1;
if (!allpaths)
break;
}
}
return (found ? 0 : -1);
}