hostname-setup.c revision 958b66ea16deddd794b3a52643bd44633e165ead
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include "macro.h"
#include "util.h"
#include "log.h"
#include "fileio.h"
#include "hostname-util.h"
#include "hostname-setup.h"
static int read_and_strip_hostname(const char *path, char **hn) {
char *s;
int r;
assert(path);
assert(hn);
r = read_one_line_file(path, &s);
if (r < 0)
return r;
hostname_cleanup(s, false);
if (isempty(s)) {
free(s);
return -ENOENT;
}
*hn = s;
return 0;
}
int hostname_setup(void) {
int r;
_cleanup_free_ char *b = NULL;
const char *hn;
bool enoent = false;
r = read_and_strip_hostname("/etc/hostname", &b);
if (r < 0) {
if (r == -ENOENT)
enoent = true;
else
log_warning_errno(r, "Failed to read configured hostname: %m");
hn = NULL;
} else
hn = b;
if (isempty(hn)) {
/* Don't override the hostname if it is already set
* and not explicitly configured */
if (hostname_is_set())
return 0;
if (enoent)
log_info("No hostname configured.");
hn = "localhost";
}
if (sethostname_idempotent(hn) < 0)
return log_warning_errno(errno, "Failed to set hostname to <%s>: %m", hn);
log_info("Set hostname to <%s>.", hn);
return 0;
}