freebsd-nq/bin/hostname/hostname.c
Kyle Evans 33c1e7271a hostname: avoid strcpy() overlap in -d flag handling
We don't need the strcpy() anyways, just use a pointer to the hostname
buffer and move it forward for `hostname -d`.

Sponsored by:	Klara, Inc.
2021-09-25 00:03:50 -05:00

117 lines
3.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if 0
#ifndef lint
static char const copyright[] =
"@(#) Copyright (c) 1988, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)hostname.c 8.1 (Berkeley) 5/31/93";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
static void usage(void) __dead2;
int
main(int argc, char *argv[])
{
int ch, sflag, dflag;
char hostname[MAXHOSTNAMELEN], *hostp, *p;
sflag = 0;
dflag = 0;
while ((ch = getopt(argc, argv, "fsd")) != -1)
switch (ch) {
case 'f':
/*
* On Linux, "hostname -f" prints FQDN.
* BSD "hostname" always prints FQDN by
* default, so we accept but ignore -f.
*/
break;
case 's':
sflag = 1;
break;
case 'd':
dflag = 1;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (argc > 1 || (sflag && dflag))
usage();
if (*argv) {
if (sethostname(*argv, (int)strlen(*argv)))
err(1, "sethostname");
} else {
hostp = hostname;
if (gethostname(hostname, (int)sizeof(hostname)))
err(1, "gethostname");
if (sflag) {
p = strchr(hostname, '.');
if (p != NULL)
*p = '\0';
} else if (dflag) {
p = strchr(hostname, '.');
if (p != NULL)
hostp = p + 1;
}
(void)printf("%s\n", hostp);
}
exit(0);
}
static void
usage(void)
{
(void)fprintf(stderr, "usage: hostname [-f] [-s | -d] [name-of-host]\n");
exit(1);
}