trace-cmd listen: Add a pid file when in daemon mode
When trace-cmd listen is started in daemon mode, create the file
/var/run/trace-cmd-net.pid that holds the pid of the daemon.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/trace-listen.c b/trace-listen.c
index 420b68d..1e3375f 100644
--- a/trace-listen.c
+++ b/trace-listen.c
@@ -37,6 +37,8 @@
#define MAX_OPTION_SIZE 4096
+#define VAR_RUN_DIR "/var/run"
+
static char *default_output_dir = ".";
static char *output_dir;
static char *default_output_file = "trace";
@@ -50,6 +52,8 @@
static int proto_ver;
+static int do_daemon;
+
#define TEMP_FILE_STR "%s.%s:%s.cpu%d", output_file, host, port, cpu
static char *get_temp_file(const char *host, const char *port, int cpu)
{
@@ -155,6 +159,24 @@
va_end(ap);
}
+static void make_pid_name(int mode, char *buf)
+{
+ snprintf(buf, PATH_MAX, VAR_RUN_DIR "/trace-cmd-net.pid");
+}
+
+static void remove_pid_file(void)
+{
+ char buf[PATH_MAX];
+ int mode = do_daemon;
+
+ if (!do_daemon)
+ return;
+
+ make_pid_name(mode, buf);
+
+ unlink(buf);
+}
+
void pdie(const char *fmt, ...)
{
va_list ap;
@@ -169,6 +191,9 @@
fprintf(logfp, "\n%s\n", str);
else
fprintf(stderr, "\n%s\n", str);
+
+ remove_pid_file();
+
exit(-1);
}
@@ -802,6 +827,28 @@
} while (!done);
}
+static void make_pid_file(void)
+{
+ char buf[PATH_MAX];
+ int mode = do_daemon;
+ int fd;
+
+ if (!do_daemon)
+ return;
+
+ make_pid_name(mode, buf);
+
+ fd = open(buf, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+ if (fd < 0) {
+ perror(buf);
+ return;
+ }
+
+ sprintf(buf, "%d\n", getpid());
+ write(fd, buf, strlen(buf));
+ close(fd);
+}
+
static void do_listen(char *port)
{
struct addrinfo hints;
@@ -811,6 +858,8 @@
if (!debug)
signal_setup(SIGCHLD, clean_up);
+ make_pid_file();
+
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
@@ -843,10 +892,14 @@
do_accept_loop(sfd);
kill_clients();
+
+ remove_pid_file();
}
static void start_daemon(void)
{
+ do_daemon = 1;
+
if (daemon(1, 0) < 0)
die("starting daemon");
}
