busybox/networking/hostname.c
2006-07-11 11:32:31 +00:00

121 lines
2.4 KiB
C

/* vi: set sw=4 ts=4: */
/*
* $Id: hostname.c,v 1.36 2003/07/14 21:21:01 andersen Exp $
* Mini hostname implementation for busybox
*
* Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
*
* adjusted by Erik Andersen <andersen@codepoet.org> to remove
* use of long options and GNU getopt. Improved the usage info.
*
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include <errno.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include "busybox.h"
extern char *optarg; /* in unistd.h */
extern int optind, opterr, optopt; /* in unistd.h */
static 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)
bb_error_msg_and_die("you must be root to change the hostname");
else
bb_perror_msg_and_die("sethostname");
}
} else {
f = bb_xfopen(s, "r");
while (fgets(buf, 255, f) != NULL) {
if (buf[0] =='#') {
continue;
}
chomp(buf);
do_sethostname(buf, 0);
}
#ifdef CONFIG_FEATURE_CLEAN_UP
fclose(f);
#endif
}
}
int hostname_main(int argc, char **argv)
{
int opt;
int type = 0;
struct hostent *hp;
char *filename = NULL;
char buf[255];
char *p = NULL;
if (argc < 1)
bb_show_usage();
while ((opt = getopt(argc, argv, "dfisF:")) > 0) {
switch (opt) {
case 'd':
case 'f':
case 'i':
case 's':
type = opt;
break;
case 'F':
filename = optarg;
break;
default:
bb_show_usage();
}
}
/* Output in desired format */
if (type != 0) {
gethostname(buf, 255);
hp = xgethostbyname(buf);
p = strchr(hp->h_name, '.');
if (type == 'f') {
puts(hp->h_name);
} else if (type == 's') {
if (p != NULL) {
*p = 0;
}
puts(hp->h_name);
} else if (type == 'd') {
if (p) puts(p + 1);
} else if (type == 'i') {
while (hp->h_addr_list[0]) {
printf("%s ", inet_ntoa(*(struct in_addr *) (*hp->h_addr_list++)));
}
printf("\n");
}
}
/* Set the hostname */
else if (filename != NULL) {
do_sethostname(filename, 1);
} else if (optind < argc) {
do_sethostname(argv[optind], 0);
}
/* Or if all else fails,
* just print the current hostname */
else {
gethostname(buf, 255);
puts(buf);
}
return(0);
}