1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1987, 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 * @(#)printenv.c 8.2 (Berkeley) 5/4/95 32 * $FreeBSD: head/usr.bin/printenv/printenv.c 335395 2018-06-19 23:43:14Z oshogbo $ 33 */ 34 35 #include <sys/types.h> 36 37 #include <err.h> 38 #include <stdlib.h> 39 #include <stdio.h> 40 #include <string.h> 41 #include <unistd.h> 42 43 void usage(void); 44 extern char **environ; 45 46 /* 47 * printenv 48 * 49 * Bill Joy, UCB 50 * February, 1979 51 */ 52 int 53 main(int argc, char *argv[]) 54 { 55 char *cp, **ep; 56 size_t len; 57 int ch; 58 59 while ((ch = getopt(argc, argv, "")) != -1) 60 switch(ch) { 61 case '?': 62 default: 63 usage(); 64 } 65 argc -= optind; 66 argv += optind; 67 68 if (argc == 0) { 69 for (ep = environ; *ep; ep++) 70 printf("%s\n", *ep); 71 exit(0); 72 } 73 len = strlen(*argv); 74 for (ep = environ; *ep; ep++) 75 if (!memcmp(*ep, *argv, len)) { 76 cp = *ep + len; 77 if (*cp == '=') { 78 printf("%s\n", cp + 1); 79 exit(0); 80 } 81 } 82 exit(1); 83 } 84 85 void 86 usage(void) 87 { 88 fprintf(stderr, "usage: printenv [name]\n"); 89 exit(1); 90 } 91