From e8f163976f4697cf68114fdc84092d8cad8c5bf4 Mon Sep 17 00:00:00 2001
From: Bent Bisballe Nyeng <deva@aasimon.org>
Date: Thu, 24 Aug 2023 20:21:42 +0200
Subject: Add option to fork to background and store pid in file.

---
 src/muniad.cc | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/src/muniad.cc b/src/muniad.cc
index 7e260be..e225760 100644
--- a/src/muniad.cc
+++ b/src/muniad.cc
@@ -32,6 +32,8 @@
 #include <string.h>
 #include <sys/time.h>
 #include <list>
+#include <string>
+#include <fstream>
 
 #include <libwebsockets.h>
 
@@ -50,6 +52,8 @@ static struct lws_protocols protocols[] =
 
 static struct option options[] = {
 	{ "help", no_argument, nullptr, 'h' },
+	{ "background", no_argument, nullptr, 'b' },
+	{ "pidfile", required_argument, nullptr, 'P' },
 	{ "port", required_argument, nullptr, 'p' },
 	{ "file", required_argument, nullptr, 'f' },
 	{ "ssl", no_argument, nullptr, 's' },
@@ -68,6 +72,8 @@ int main(int argc, char **argv)
 	const char *key_path =
 		LOCAL_RESOURCE_PATH"/libwebsockets-test-server.key.pem";
 
+	std::string pidfile;
+	bool background{false};
 	int port = 7681;
 	int use_ssl = 0;
 	struct lws_context *context;
@@ -87,7 +93,7 @@ int main(int argc, char **argv)
 
 	while(n >= 0)
 	{
-		n = getopt_long(argc, argv, "ci:khsp:f:", options, nullptr);
+		n = getopt_long(argc, argv, "ci:khsp:f:P:b", options, nullptr);
 		if(n < 0)
 		{
 			continue;
@@ -106,6 +112,12 @@ int main(int argc, char **argv)
 		case 'p':
 			port = atoi(optarg);
 			break;
+		case 'P':
+			pidfile = optarg;
+			break;
+		case 'b':
+			background = true;
+			break;
 		case 'f':
 			db_filename = strdup(optarg);
 			break;
@@ -115,12 +127,25 @@ int main(int argc, char **argv)
 			interface = interface_name;
 			break;
 		case 'h':
-			fprintf(stderr, "Usage: muniad [--port=<p>] [--ssl] [--file=<f>]\n");
+			fprintf(stderr, "Usage: muniad [--port=<p>] [--ssl] [--file=<f>] [--background] [--pidfile=<f>]\n");
 			exit(1);
 		}
 	}
 
 	//_parse("+all");
+	if(background)
+	{
+		// Fork, chdir to / and redirect stdout and stderr to /dev/null
+		daemon(0, 0);
+		// Create a new session, make the current process process group leader.
+		setsid();
+	}
+
+	if(!pidfile.empty())
+	{
+		std::ofstream fs(pidfile);
+		fs << getpid() << '\n';
+	}
 
 	node_manager.init(db_filename);
 
-- 
cgit v1.2.3