Write pidfile when daemonized (GitHub issue #10)

README.markdown

@@ -38,7 +38,7 @@ curl -d "GET/hello" http://127.0.0.1:7379/
 * Cross-origin requests, usable with XMLHttpRequest2 (Cross-Origin Resource Sharing - CORS).
 * File upload with PUT.
 * With the JSON output, the return value of INFO is parsed and transformed into an object.
-* Optional daemonize.
+* Optional daemonize: set `"daemonize": true` and `"pidfile": "/var/run/webdis.pid"` in webdis.json.
 * Default root object: Add `"default_root": "/GET/index.html"` in webdis.json to substitute the request to `/` with a Redis request.
 * HTTP request limit with `http_max_request_size` (in bytes, set to 128MB by default).
 * Database selection in the URL, using e.g. `/7/GET/key` to run the command on DB 7.

conf.c

@@ -37,6 +37,7 @@ conf_read(const char *filename) {
 	conf->logfile = "webdis.log";
 	conf->verbosity = WEBDIS_NOTICE;
 	conf->daemonize = 0;
+	conf->pidfile = "webdis.pid";
 	conf->database = 0;
 	conf->pool_size_per_thread = 2;
 
@@ -86,6 +87,8 @@ conf_read(const char *filename) {
 			else conf->verbosity = (log_level)tmp;
 		} else if(strcmp(json_object_iter_key(kv), "daemonize") == 0 && json_typeof(jtmp) == JSON_TRUE) {
 			conf->daemonize = 1;
+		} else if(strcmp(json_object_iter_key(kv),"pidfile") == 0 && json_typeof(jtmp) == JSON_STRING){
+			conf->pidfile = strdup(json_string_value(jtmp));
 		} else if(strcmp(json_object_iter_key(kv), "websockets") == 0 && json_typeof(jtmp) == JSON_TRUE) {
 			conf->websockets = 1;
 		} else if(strcmp(json_object_iter_key(kv), "database") == 0 && json_typeof(jtmp) == JSON_INTEGER) {

conf.h

@@ -22,6 +22,7 @@ struct conf {
 
 	/* daemonize process, off by default */
 	int daemonize;
+	char *pidfile;
 
 	/* WebSocket support, off by default */
 	int websockets;

server.c

@@ -130,7 +130,7 @@ server_can_accept(int fd, short event, void *ptr) {
  * (taken from Redis)
  */
 static void
-server_daemonize(void) {
+server_daemonize(const char *pidfile) {
 	int fd;
 
 	if (fork() != 0) exit(0); /* parent exits */
@@ -143,8 +143,16 @@ server_daemonize(void) {
 		dup2(fd, STDERR_FILENO);
 		if (fd > STDERR_FILENO) close(fd);
 	}
-}
 
+	/* write pidfile */
+	if (pidfile) {
+		FILE *f = fopen(pidfile, "w");
+		if (f) {
+			fprintf(f, "%d\n", (int)getpid());
+			fclose(f);
+		}
+	}
+}
 
 int
 server_start(struct server *s) {
@@ -155,7 +163,7 @@ server_start(struct server *s) {
 	s->base = event_base_new();
 
 	if(s->cfg->daemonize) {
-		server_daemonize();
+		server_daemonize(s->cfg->pidfile);
 
 		/* sometimes event mech gets lost on fork */
 		if(event_reinit(s->base) != 0) {