1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1988, 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 #if 0 33 #ifndef lint 34 static char const copyright[] = 35 "@(#) Copyright (c) 1988, 1993\n\ 36 The Regents of the University of California. All rights reserved.\n"; 37 #endif /* not lint */ 38 39 #ifndef lint 40 static char sccsid[] = "@(#)hostname.c 8.1 (Berkeley) 5/31/93"; 41 #endif /* not lint */ 42 #endif 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include <sys/param.h> 47 48 #include <err.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 54 static void usage(void) __dead2; 55 56 int 57 main(int argc, char *argv[]) 58 { 59 int ch, sflag, dflag; 60 char hostname[MAXHOSTNAMELEN], *hostp, *p; 61 62 sflag = 0; 63 dflag = 0; 64 while ((ch = getopt(argc, argv, "fsd")) != -1) 65 switch (ch) { 66 case 'f': 67 /* 68 * On Linux, "hostname -f" prints FQDN. 69 * BSD "hostname" always prints FQDN by 70 * default, so we accept but ignore -f. 71 */ 72 break; 73 case 's': 74 sflag = 1; 75 break; 76 case 'd': 77 dflag = 1; 78 break; 79 case '?': 80 default: 81 usage(); 82 } 83 argc -= optind; 84 argv += optind; 85 86 if (argc > 1 || (sflag && dflag)) 87 usage(); 88 89 if (*argv) { 90 if (sethostname(*argv, (int)strlen(*argv))) 91 err(1, "sethostname"); 92 } else { 93 hostp = hostname; 94 if (gethostname(hostname, (int)sizeof(hostname))) 95 err(1, "gethostname"); 96 if (sflag) { 97 p = strchr(hostname, '.'); 98 if (p != NULL) 99 *p = '\0'; 100 } else if (dflag) { 101 p = strchr(hostname, '.'); 102 if (p != NULL) 103 hostp = p + 1; 104 } 105 (void)printf("%s\n", hostp); 106 } 107 exit(0); 108 } 109 110 static void 111 usage(void) 112 { 113 114 (void)fprintf(stderr, "usage: hostname [-f] [-s | -d] [name-of-host]\n"); 115 exit(1); 116 } 117