IABSD.fr/src/usr.bin/which/which.c

Branch : - branch - master - tag -

• Show log

  Commit

• Author : millert
  Date : 2019-01-25 00:19:25
  Hash : bf198cc6
  Message : I am retiring my old email address; replace it with my OpenBSD one.

• usr.bin/which/which.c

• /*	$OpenBSD: which.c,v 1.27 2019/01/25 00:19:27 millert Exp $	*/
  
  /*
   * Copyright (c) 1997 Todd C. Miller <millert@openbsd.org>
   *
   * 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 <limits.h>
  #include <paths.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  #define PROG_WHICH	1
  #define PROG_WHEREIS	2
  
  extern char *__progname;
  
  int findprog(char *, char *, int, int);
  static void __dead 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;
  
  	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++;
  
  	return ((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);
  }
  
  static void __dead
  usage(void)
  {
  	(void)fprintf(stderr, "usage: %s [-a] name ...\n", __progname);
  	exit(1);
  }