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#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
void *xmalloc(size_t size)
{
void *p = malloc(size);
if (p == NULL)
err(EXIT_FAILURE, "malloc");
return p;
}
static int ping(const char *host)
{
char cmd[280];
snprintf(cmd, sizeof(cmd), "ping -c 1 -q %s", host);
return system(cmd);
}
void usage(int retcode)
{
fprintf(stderr, "usage:\n");
exit(retcode);
}
void ping_loop(char *hosts[], int offline[], int count, int interval)
{
int i;
while (1) {
for (i = 0; i < count; i++) {
int status = (ping(hosts[i]) != 0);
if (status != offline[i]) {
offline[i] = status;
printf("status changed for %s to %i\n",
hosts[i], status);
}
}
sleep(interval);
}
}
int main(int argc, char *argv[])
{
int c;
char **hosts;
int *offline;
int hosts_count;
int interval = 30;
const char *script = NULL;
while ((c = getopt(argc, argv, "i:s:")) != -1) {
switch (c) {
case 's':
script = optarg;
break;
case 'i':
interval = atoi(optarg);
break;
}
}
argc -= optind;
argv += optind;
if (argc == 0)
usage(EXIT_FAILURE);
offline = xmalloc(sizeof(int) * argc);
memset(offline, 0, sizeof(int) * argc);
ping_loop(argv, offline, argc, interval);
free(hosts);
return 0;
}
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