diff options
Diffstat (limited to 'hostname.c')
| -rw-r--r-- | hostname.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/hostname.c b/hostname.c new file mode 100644 index 0000000..27f2800 --- /dev/null +++ b/hostname.c @@ -0,0 +1,126 @@ +/* + * $Id: hostname.c,v 1.1 1999/12/07 23:14:59 andersen Exp $ + * Mini hostname implementation for busybox + * + * Copyright (C) 1999 by Randolph Chung <tausq@debian.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include "internal.h" +#include <errno.h> +#include <getopt.h> +#include <arpa/inet.h> +#include <netdb.h> +#include <unistd.h> +#include <stdio.h> + +static const char* hostname_usage = "hostname [OPTION] {hostname | -F file}\n\n" +"Options:\n" +"\t-s, --short\t\tshort\n" +"\t-i, --ip-address\t\taddresses for the hostname\n" +"\t-d, --domain\t\tDNS domain name\n" +"If a hostname is given, or a file is given with the -F parameter, the host\n" +"name will be set\n"; + +static char short_opts[] = "sidF:"; +static const struct option long_opts[] = { + { "short", no_argument, NULL, 's' }, + { "ip-address", no_argument, NULL, 'i' }, + { "domain", no_argument, NULL, 'd' }, + { NULL, 0, NULL, 0 } +}; + +void do_sethostname(char *s, int isfile) +{ + FILE *f; + char buf[255]; + + if (!s) return; + if (!isfile) { + if (sethostname(s, strlen(s)) < 0) { + if (errno == EPERM) + fprintf(stderr, "hostname: you must be root to change the hostname\n"); + else + perror("sethostname"); + exit(1); + } + } else { + if ((f = fopen(s, "r")) == NULL) { + perror(s); + exit(1); + } else { + fgets(buf, 255, f); + fclose(f); + if (buf[strlen(buf)-1] == '\n') buf[strlen(buf)-1] = 0; + if (sethostname(buf, strlen(buf)) < 0) { + perror("sethostname"); + exit(1); + } + } + } +} + +int hostname_main(int argc, char **argv) +{ + int c; + int opt_short = 0; + int opt_domain = 0; + int opt_ip = 0; + int opt_file = 0; + struct hostent *h; + char *filename = NULL; + char buf[255]; + char *s = NULL; + + if (argc < 1) usage(hostname_usage); + + while ((c = getopt_long(argc, argv, short_opts, long_opts, NULL)) != -1) { + switch (c) { + case 's': opt_short = 1; break; + case 'i': opt_ip = 1; break; + case 'd': opt_domain = 1; break; + case 'F': opt_file = 1; filename = optarg; break; + default: usage(hostname_usage); + } + } + + if (optind < argc) { + do_sethostname(argv[optind], 0); + } else if (opt_file) { + do_sethostname(filename, 1); + } else { + gethostname(buf, 255); + if (opt_short) { + s = strchr(buf, '.'); + if (!s) s = buf; *s = 0; + printf("%s\n", buf); + } else if (opt_domain) { + s = strchr(buf, '.'); + printf("%s\n", (s ? s+1 : "")); + } else if (opt_ip) { + h = gethostbyname(buf); + if (!h) { + printf("Host not found\n"); + exit(1); + } + printf("%s\n", inet_ntoa(*(struct in_addr *)(h->h_addr))); + } else { + printf("%s\n", buf); + } + } + return 0; +} + |