lxc_monitor.c revision 96f3e4ebd4c232776e35ae85a88f25b206e280af
/*
* lxc: linux Container library
*
* (C) Copyright IBM Corp. 2007, 2008
*
* Authors:
* Daniel Lezcano <dlezcano at fr.ibm.com>
*
* This library 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.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <libgen.h>
#include <lxc/lxc.h>
void usage(char *cmd)
{
fprintf(stderr, "%s <command>\n", basename(cmd));
fprintf(stderr, "\t -n <name> : name of the container\n");
_exit(1);
}
int main(int argc, char *argv[])
{
char opt;
char *name = NULL;
int fds[2];
pid_t pid;
while ((opt = getopt(argc, argv, "n:")) != -1) {
switch (opt) {
case 'n':
name = optarg;
break;
}
}
if (!name)
usage(argv[0]);
if (pipe(fds)) {
perror("pipe");
return 1;
}
pid = fork();
if (pid < 0) {
perror("fork");
return 1;
}
if (!pid) {
close(fds[0]);
if (lxc_monitor(name, fds[1])) {
fprintf(stderr, "failed to monitor %s\n", name);
return 1;
}
return 0;
}
close(fds[1]);
for (;;) {
int err, state;
err = read(fds[0], &state, sizeof(state));
if (err < 0) {
perror("read");
return 1;
}
if (!err) {
printf("container has been destroyed\n");
return 0;
}
printf("container has changed the state to %d - %s\n",
state, lxc_state2str(state));
}
return 0;
}