Daemon: Added a new daemon-control utility

diff --git a/ucw/daemon.h b/ucw/daemon.h
index 288a05c269cf073d7986a93f84ba0037dbd363a8..c99f8e0849f5f525efbdfe7b632421ed9327edfa 100644 (file)
--- 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 3227bb0a7401a302a33d63ed77c6f784aa14aab8..20de4727e26852960d2d9647efc52084a354ebda 100644 (file)
--- 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 (file)
index 0000000..85fb450
--- /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;
+}