minix/usr.bin/whereis/whereis.c

/*	$NetBSD: whereis.c,v 1.21 2008/10/17 10:53:26 apb Exp $	*/

/*-
 * Copyright (c) 1993
 *	The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)whereis.c	8.3 (Berkeley) 5/4/95";
#endif
__RCSID("$NetBSD: whereis.c,v 1.21 2008/10/17 10:53:26 apb Exp $");
#endif /* not lint */

#include <sys/param.h>
#include <sys/stat.h>
#include <sys/sysctl.h>

#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

static void usage(void) __dead;

int
main(int argc, char *argv[])
{
	struct stat sb;
	size_t len;
#ifdef __minix
	int ch;
#else
	int ch, mib[2];
#endif /* def __minix */
	char *p, *std, path[MAXPATHLEN];
	const char *t;
	int which = strcmp(getprogname(), "which") == 0;
	int useenvpath = which, found = 0;
	gid_t egid = getegid();
	uid_t euid = geteuid();

	/* To make access(2) do what we want */
	if (setgid(egid) == -1)
		err(1, "Can't set gid to %lu", (unsigned long)egid);
	if (setuid(euid) == -1)
		err(1, "Can't set uid to %lu", (unsigned long)euid);

	while ((ch = getopt(argc, argv, "ap")) != -1)
		switch (ch) {
		case 'a':
			which = 0;
			break;
		case 'p':
			useenvpath = 1;	/* use environment for PATH */
			break;

		case '?':
		default:
			usage();
		}
	argc -= optind;
	argv += optind;

	if (argc == 0)
		usage();

 	if (useenvpath) {
 		if ((std = getenv("PATH")) == NULL)
 			errx(1, "PATH environment variable is not set");
	} else {
		/* Retrieve the standard path. */
#ifdef __minix
		/*
			Note: This path is currently defined here and should probably be defined
			here, in "ash" or in "sh".
			To minimize code changes, the path has been hard coded into this file.
			However, if this path needs to be used in other ported programs, please
			move this define to <minix/paths.h> and add the include to this file
			and all files that use _PATH_USER_CS_PATH.
		 */
		#define _PATH_USER_CS_PATH "/usr/X11R7/sbin:/usr/local/sbin:/usr/pkg/sbin:/usr/sbin:/sbin:/usr/X11R7/bin:/usr/local/bin:/usr/pkg/bin:/usr/bin:/bin:/usr/games"
		std = strdup(_PATH_USER_CS_PATH);
#else
		mib[0] = CTL_USER;
		mib[1] = USER_CS_PATH;
		if (sysctl(mib, 2, NULL, &len, NULL, 0) == -1)
			err(1, "sysctl: user.cs_path");
		if (len == 0)
			errx(1, "sysctl: user.cs_path (zero length)");
		if ((std = malloc(len)) == NULL)
			err(1, NULL);
		if (sysctl(mib, 2, std, &len, NULL, 0) == -1)
			err(1, "sysctl: user.cs_path");
#endif /* def __minix */
	}

	/* For each path, for each program... */
	for (; *argv; ++argv) {
		if (**argv == '/') {
			if (stat(*argv, &sb) == -1)
				continue; /* next argv */
			if (!S_ISREG(sb.st_mode))
				continue; /* next argv */
			if (access(*argv, X_OK) == -1)
				continue; /* next argv */
			(void)printf("%s\n", *argv);
			found++;
			if (which)
				continue; /* next argv */
		} else for (p = std; p; ) {
			t = p;
			if ((p = strchr(p, ':')) != NULL) {
				*p = '\0';
				if (t == p)
					t = ".";
			} else
				if (strlen(t) == 0)
					t = ".";
			(void)snprintf(path, sizeof(path), "%s/%s", t, *argv);
			len = snprintf(path, sizeof(path), "%s/%s", t, *argv);
			if (p)
				*p++ = ':';
			if (len >= sizeof(path))
				continue; /* next p */
			if (stat(path, &sb) == -1)
				continue; /* next p */
			if (!S_ISREG(sb.st_mode))
				continue; /* next p */
			if (access(path, X_OK) == -1)
				continue; /* next p */
			(void)printf("%s\n", path);
			found++;
			if (which)
				break; /* next argv */
		}
	}
	
	return ((found == 0) ? 3 : ((found >= argc) ? 0 : 2));
}

static void
usage(void)
{

	(void)fprintf(stderr, "Usage: %s [-ap] program [...]\n", getprogname());
	exit(1);
}