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      1 /*	$NetBSD: whereis.c,v 1.22 2025/06/01 15:45:31 jschauma Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 __COPYRIGHT("@(#) Copyright (c) 1993\
     35  The Regents of the University of California.  All rights reserved.");
     36 #endif /* not lint */
     37 
     38 #ifndef lint
     39 #if 0
     40 static char sccsid[] = "@(#)whereis.c	8.3 (Berkeley) 5/4/95";
     41 #endif
     42 __RCSID("$NetBSD: whereis.c,v 1.22 2025/06/01 15:45:31 jschauma Exp $");
     43 #endif /* not lint */
     44 
     45 #include <sys/param.h>
     46 #include <sys/stat.h>
     47 #include <sys/sysctl.h>
     48 
     49 #include <err.h>
     50 #include <errno.h>
     51 #include <stdio.h>
     52 #include <stdlib.h>
     53 #include <string.h>
     54 #include <unistd.h>
     55 
     56 static void usage(void) __dead;
     57 
     58 int
     59 main(int argc, char *argv[])
     60 {
     61 	struct stat sb;
     62 	size_t len;
     63 	int ch, mib[2];
     64 	char *p, *std, path[MAXPATHLEN];
     65 	const char *t;
     66 	int which = strcmp(getprogname(), "which") == 0;
     67 	int useenvpath = which, found = 0;
     68 	gid_t egid = getegid();
     69 	uid_t euid = geteuid();
     70 
     71 	/* To make access(2) do what we want */
     72 	if (setregid(egid, egid) == -1)
     73 		err(1, "Can't set gid to %lu", (unsigned long)egid);
     74 	if (setreuid(euid, euid) == -1)
     75 		err(1, "Can't set uid to %lu", (unsigned long)euid);
     76 
     77 	while ((ch = getopt(argc, argv, "ap")) != -1)
     78 		switch (ch) {
     79 		case 'a':
     80 			which = 0;
     81 			break;
     82 		case 'p':
     83 			useenvpath = 1;	/* use environment for PATH */
     84 			break;
     85 
     86 		case '?':
     87 		default:
     88 			usage();
     89 		}
     90 	argc -= optind;
     91 	argv += optind;
     92 
     93 	if (argc == 0)
     94 		usage();
     95 
     96  	if (useenvpath) {
     97  		if ((std = getenv("PATH")) == NULL)
     98  			errx(1, "PATH environment variable is not set");
     99 	} else {
    100 		/* Retrieve the standard path. */
    101 		mib[0] = CTL_USER;
    102 		mib[1] = USER_CS_PATH;
    103 		if (sysctl(mib, 2, NULL, &len, NULL, 0) == -1)
    104 			err(1, "sysctl: user.cs_path");
    105 		if (len == 0)
    106 			errx(1, "sysctl: user.cs_path (zero length)");
    107 		if ((std = malloc(len)) == NULL)
    108 			err(1, NULL);
    109 		if (sysctl(mib, 2, std, &len, NULL, 0) == -1)
    110 			err(1, "sysctl: user.cs_path");
    111 	}
    112 
    113 	/* For each path, for each program... */
    114 	for (; *argv; ++argv) {
    115 		if (**argv == '/') {
    116 			if (stat(*argv, &sb) == -1)
    117 				continue; /* next argv */
    118 			if (!S_ISREG(sb.st_mode))
    119 				continue; /* next argv */
    120 			if (access(*argv, X_OK) == -1)
    121 				continue; /* next argv */
    122 			(void)printf("%s\n", *argv);
    123 			found++;
    124 			if (which)
    125 				continue; /* next argv */
    126 		} else for (p = std; p; ) {
    127 			t = p;
    128 			if ((p = strchr(p, ':')) != NULL) {
    129 				*p = '\0';
    130 				if (t == p)
    131 					t = ".";
    132 			} else
    133 				if (strlen(t) == 0)
    134 					t = ".";
    135 			(void)snprintf(path, sizeof(path), "%s/%s", t, *argv);
    136 			len = snprintf(path, sizeof(path), "%s/%s", t, *argv);
    137 			if (p)
    138 				*p++ = ':';
    139 			if (len >= sizeof(path))
    140 				continue; /* next p */
    141 			if (stat(path, &sb) == -1)
    142 				continue; /* next p */
    143 			if (!S_ISREG(sb.st_mode))
    144 				continue; /* next p */
    145 			if (access(path, X_OK) == -1)
    146 				continue; /* next p */
    147 			(void)printf("%s\n", path);
    148 			found++;
    149 			if (which)
    150 				break; /* next argv */
    151 		}
    152 	}
    153 
    154 	return ((found == 0) ? 3 : ((found >= argc) ? 0 : 2));
    155 }
    156 
    157 static void
    158 usage(void)
    159 {
    160 
    161 	(void)fprintf(stderr, "Usage: %s [-ap] program [...]\n", getprogname());
    162 	exit(1);
    163 }
    164