cmd-timer

commit: ea42a009ba74ddbcc010f5a8549abe686e2622cc
parent 58cf416e23ac8c5adbccd9d8bb20f6df0de59c56
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date:   Wed, 30 Jul 2025 15:15:24 +0200

Add -w option

Diffstat:
M
timer.1
13
+++++++++++++
M
timer.c
32
+++++++++++++++++++++++++-------

2 files changed, 38 insertions(+), 7 deletions(-)
diff --git a/timer.1 b/timer.1
@@ -8,6 +8,7 @@
 .Nd run command at a specific interval
 .Sh SYNOPSIS
 .Nm
+.Op Fl w
 .Ar interval
 .Ar command
 .Op Ar arguments
@@ -31,6 +32,18 @@ If
 exits with a non-zero status,
 .Nm
 exits with the same status, allowing to use service supervision to track failures.
+.Sh OPTIONS
+.Bl -item -width Ds
+.It Fl w
+Wait for
+.Ar interval
+to elapse.
+Otherwise
+.Nm
+immediately runs
+.Ar command
+after starting.
+.El
 .Sh EXIT STATUS
 .Ex -std
 .Sh EXAMPLES
diff --git a/timer.c b/timer.c
@@ -5,15 +5,16 @@
 #include "strtodur.h"
 
 #include <errno.h>
-#include <limits.h>   // UINT_MAX
-#include <signal.h>   // sigaction
-#include <spawn.h>    // posix_spawnp
+#include <limits.h> // UINT_MAX
+#include <signal.h> // sigaction
+#include <spawn.h>  // posix_spawnp
+#include <stdbool.h>
 #include <stdio.h>    // fprintf, fputs
 #include <stdlib.h>   // exit
 #include <string.h>   // strerror
 #include <sys/wait.h> // waitpid
 #include <time.h>     // timer_create
-#include <unistd.h>   // sleep
+#include <unistd.h>   // sleep, getopt
 
 extern char **environ;
 static char **args;
@@ -47,7 +48,7 @@ sig_chld(int sig)
 static void
 bad_usage()
 {
-	fputs("Usage: timer <interval> <command> [arguments...]\n", stderr);
+	fputs("Usage: timer [-w] <interval> <command> [arguments...]\n", stderr);
 	exit(1);
 }
 
@@ -61,8 +62,23 @@ timer_errx(int err, char *msg)
 int
 main(int argc, char *argv[])
 {
-	argc--;
-	argv++;
+	bool opt_w = false;
+
+	for(char c = -1; (c = getopt(argc, argv, ":w")) != -1;)
+	{
+		switch(c)
+		{
+		case 'w':
+			opt_w = true;
+			break;
+		default:
+			fprintf(stderr, "timer: error: Unhandled option -%c\n", optopt);
+			return 1;
+		}
+	}
+
+	argc -= optind;
+	argv += optind;
 
 	if(argc < 2)
 	{
@@ -146,6 +162,8 @@ main(int argc, char *argv[])
 	if(sigdelset(&sigmask, SIGTERM) != 0)
 		timer_errx(1, "Failed adding SIGTERM to sigsuspend sigmask");
 
+	if(!opt_w) sig_timer(0);
+
 	while(sigsuspend(&sigmask))
 		;