printenv.c revision 102944
1/* 2 * Copyright (c) 1987, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34#ifndef lint 35static const char copyright[] = 36"@(#) Copyright (c) 1987, 1993\n\ 37 The Regents of the University of California. All rights reserved.\n"; 38#endif /* not lint */ 39 40#if 0 41#ifndef lint 42static char sccsid[] = "@(#)printenv.c 8.2 (Berkeley) 5/4/95"; 43#endif /* not lint */ 44#endif 45 46#include <sys/cdefs.h> 47__FBSDID("$FreeBSD: head/usr.bin/printenv/printenv.c 102944 2002-09-04 23:29:10Z dwmalone $"); 48 49#include <sys/types.h> 50 51#include <stdlib.h> 52#include <stdio.h> 53#include <string.h> 54#include <unistd.h> 55 56void usage(void); 57 58/* 59 * printenv 60 * 61 * Bill Joy, UCB 62 * February, 1979 63 */ 64int 65main(int argc, char *argv[]) 66{ 67 extern char **environ; 68 char *cp, **ep; 69 size_t len; 70 int ch; 71 72 while ((ch = getopt(argc, argv, "")) != -1) 73 switch(ch) { 74 case '?': 75 default: 76 usage(); 77 } 78 argc -= optind; 79 argv += optind; 80 81 if (argc == 0) { 82 for (ep = environ; *ep; ep++) 83 (void)printf("%s\n", *ep); 84 exit(0); 85 } 86 len = strlen(*argv); 87 for (ep = environ; *ep; ep++) 88 if (!memcmp(*ep, *argv, len)) { 89 cp = *ep + len; 90 if (!*cp || *cp == '=') { 91 (void)printf("%s\n", *cp ? cp + 1 : cp); 92 exit(0); 93 } 94 } 95 exit(1); 96} 97 98void 99usage(void) 100{ 101 (void)fprintf(stderr, "usage: printenv [name]\n"); 102 exit(1); 103} 104