From 468db9e951d59f64a479233df5c8c8ccae477d3a Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Wed, 18 Jul 2012 12:15:58 +0200
Subject: [PATCH] Daemon: Added a new daemon-control utility

---
 ucw/daemon.h               |   1 +
 ucw/utils/Makefile         |   3 +-
 ucw/utils/daemon-control.c | 122 +++++++++++++++++++++++++++++++++++++
 3 files changed, 125 insertions(+), 1 deletion(-)
 create mode 100644 ucw/utils/daemon-control.c

diff --git a/ucw/daemon.h b/ucw/daemon.h
index 288a05c2..c99f8e08 100644
--- a/ucw/daemon.h
+++ b/ucw/daemon.h
@@ -89,6 +89,7 @@ enum daemon_control_action {
  **/
 enum daemon_control_status daemon_control(struct daemon_control_params *dc);
 
+// XXX: Also used as exit codes of the daemon-control utility.
 enum daemon_control_status {
   DAEMON_STATUS_OK = 0,
   DAEMON_STATUS_ALREADY_DONE = 100,
diff --git a/ucw/utils/Makefile b/ucw/utils/Makefile
index 3227bb0a..20de4727 100644
--- a/ucw/utils/Makefile
+++ b/ucw/utils/Makefile
@@ -1,11 +1,12 @@
 # Makefile for the UCW utilities (c) 2008 Michal Vaner <vorner@ucw.cz>
 
-UCW_UTILS=$(addprefix $(o)/ucw/utils/,basecode daemon-helper rotate-log urltool)
+UCW_UTILS=$(addprefix $(o)/ucw/utils/,basecode daemon-helper daemon-control rotate-log urltool)
 PROGS+=$(UCW_UTILS)
 DIRS+=ucw/utils
 
 $(o)/ucw/utils/basecode: $(o)/ucw/utils/basecode.o $(LIBUCW)
 $(o)/ucw/utils/daemon-helper: $(o)/ucw/utils/daemon-helper.o $(LIBUCW)
+$(o)/ucw/utils/daemon-control: $(o)/ucw/utils/daemon-control.o $(LIBUCW)
 $(o)/ucw/utils/urltool: $(o)/ucw/utils/urltool.o $(LIBUCW)
 
 TESTS+=$(o)/ucw/utils/basecode.test
diff --git a/ucw/utils/daemon-control.c b/ucw/utils/daemon-control.c
new file mode 100644
index 00000000..85fb4501
--- /dev/null
+++ b/ucw/utils/daemon-control.c
@@ -0,0 +1,122 @@
+/*
+ *	A Simple Utility for Controlling Daemons
+ *
+ *	(c) 2012 Martin Mares <mj@ucw.cz>
+ *
+ *	For more information, see ucw/doc/daemon.txt.
+ *
+ *	Return codes:
+ *	100	already done
+ *	101	not running
+ *	102	error
+ */
+
+#include <ucw/lib.h>
+#include <ucw/daemon.h>
+#include <ucw/signames.h>
+#include <ucw/string.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <signal.h>
+#include <getopt.h>
+
+static int action;
+
+static struct option options[] = {
+  { "pid-file",		required_argument,	NULL,		'p' },
+  { "guard-file",	required_argument,	NULL,		'g' },
+  { "signal",		required_argument,	NULL,		's' },
+  { "start",		no_argument,		&action,	DAEMON_CONTROL_START },
+  { "stop",		no_argument,		&action,	DAEMON_CONTROL_STOP },
+  { "check",		no_argument,		&action,	DAEMON_CONTROL_CHECK },
+  { "reload",		no_argument,		&action,	DAEMON_CONTROL_SIGNAL },
+  { NULL,		no_argument,		NULL,		0 }
+};
+
+static void NONRET
+usage(void)
+{
+  fputs("\n\
+Usage: daemon-control --start <options> -- <daemon> <args>\n\
+   or: daemon-control --stop <options>\n\
+   or: daemon-control --reload <options>\n\
+   or: daemon-control --check <options>\n\
+\n\
+Options:\n\
+--pid-file <name>	Name of PID file for this daemon (mandatory)\n\
+--guard-file <name>	Name of guard file (default: derived from --pid-file)\n\
+--signal <sig>		Send a signal of a given name or number\n\
+			Default: SIGTERM for --stop, SIGHUP for --reload\n\
+\n\
+Exit codes:\n\
+0			Successfully completed\n\
+1			Invalid arguments\n\
+100			The action was null (e.g., --stop on a stopped daemon)\n\
+101			The daemon was not running (on --reload or --check)\n\
+102			The action has failed (error message was printed to stderr)\n\
+", stderr);
+  exit(1);
+}
+
+int
+main(int argc, char **argv)
+{
+  int c, sig;
+  struct daemon_control_params dc = { };
+
+  while ((c = getopt_long(argc, argv, "", options, NULL)) >= 0)
+    switch (c)
+      {
+      case 0:
+	break;
+      case 'p':
+	dc.pid_file = optarg;
+	break;
+      case 'g':
+	dc.guard_file = optarg;
+	break;
+      case 's':
+	sig = sig_name_to_number(optarg);
+	if (sig < 0)
+	  {
+	    fprintf(stderr, "%s: Unknown signal %s\n", argv[0], optarg);
+	    return 1;
+	  }
+	dc.signal = sig;
+	break;
+      default:
+	usage();
+      }
+  if (!dc.pid_file || !action)
+    usage();
+  dc.action = action;
+
+  if (action == DAEMON_CONTROL_START)
+    {
+      if (optind >= argc)
+	usage();
+      dc.argv = argv + optind;
+    }
+  else if (optind < argc)
+    usage();
+
+  if (!dc.guard_file)
+    {
+      if (!str_has_suffix(dc.pid_file, ".pid"))
+	{
+	  fprintf(stderr, "%s: For automatic choice of --guard-file, the --pid-file must end with `.pid'\n", argv[0]);
+	  return 1;
+	}
+      int len = strlen(dc.pid_file);
+      char *buf = xmalloc(len + 2);
+      sprintf(buf, "%.*s.lock", len-4, dc.pid_file);
+      dc.guard_file = buf;
+    }
+
+  int err = daemon_control(&dc);
+  if (err == DAEMON_STATUS_ERROR)
+    fprintf(stderr, "%s: %s\n", argv[0], dc.error_msg);
+  return err;
+}
-- 
2.39.2