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 #include <sys/param.h> 45 46 #include <err.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <unistd.h> 51 52 static void usage(void) __dead2; 53 54 int 55 main(int argc, char *argv[]) 56 { 57 int ch, sflag, dflag; 58 char hostname[MAXHOSTNAMELEN], *hostp, *p; 59 60 sflag = 0; 61 dflag = 0; 62 while ((ch = getopt(argc, argv, "fsd")) != -1) 63 switch (ch) { 64 case 'f': 65 /* 66 * On Linux, "hostname -f" prints FQDN. 67 * BSD "hostname" always prints FQDN by 68 * default, so we accept but ignore -f. 69 */ 70 break; 71 case 's': 72 sflag = 1; 73 break; 74 case 'd': 75 dflag = 1; 76 break; 77 case '?': 78 default: 79 usage(); 80 } 81 argc -= optind; 82 argv += optind; 83 84 if (argc > 1 || (sflag && dflag)) 85 usage(); 86 87 if (*argv) { 88 if (sethostname(*argv, (int)strlen(*argv))) 89 err(1, "sethostname"); 90 } else { 91 hostp = hostname; 92 if (gethostname(hostname, (int)sizeof(hostname))) 93 err(1, "gethostname"); 94 if (sflag) { 95 p = strchr(hostname, '.'); 96 if (p != NULL) 97 *p = '\0'; 98 } else if (dflag) { 99 p = strchr(hostname, '.'); 100 if (p != NULL) 101 hostp = p + 1; 102 } 103 (void)printf("%s\n", hostp); 104 } 105 exit(0); 106 } 107 108 static void 109 usage(void) 110 { 111 112 (void)fprintf(stderr, "usage: hostname [-f] [-s | -d] [name-of-host]\n"); 113 exit(1); 114 } 115