From 3adee5dcb970c88d6eac6de72e5fc19965f341d9 Mon Sep 17 00:00:00 2001 From: Natanael Copa Date: Fri, 23 Mar 2012 15:42:32 +0100 Subject: pingu: avoid running in foreground if already forked --- pingu.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/pingu.c b/pingu.c index 40f278f..badd735 100644 --- a/pingu.c +++ b/pingu.c @@ -3,6 +3,7 @@ #include #include +#include #include #include #include @@ -120,6 +121,22 @@ static void sigint_cb(struct ev_loop *loop, ev_signal *w, int revents) ev_break(loop, EVBREAK_ALL); } +static pid_t get_running_pid(void) { + size_t n; + int fd; + char buf[32] = "/proc/"; + fd = open(pid_file, O_RDONLY); + if (fd < 0) + return 0; + n = read(fd, &buf[6], sizeof(buf)-7); + close(fd); + if (n < sizeof(buf)-6) + buf[5+n] = '\0'; /* chomp newline */ + if (access(buf, R_OK) == 0) + return atoi(&buf[6]); + return 0; +} + int main(int argc, char *argv[]) { int c; @@ -128,6 +145,7 @@ int main(int argc, char *argv[]) int verbose = 0; static struct ev_loop *loop; static struct ev_signal signal_watcher; + pid_t pid; while ((c = getopt(argc, argv, "a:c:dhp:Vv")) != -1) { switch (c) { @@ -158,6 +176,11 @@ int main(int argc, char *argv[]) argv += optind; log_init("pingu", verbose); + + pid = get_running_pid(); + if (pid) + errx(1, "appears to be running already (pid %i)", pid); + loop = ev_default_loop(0); if (pingu_conf_parse(config_file) < 0) -- cgit v1.2.3