rtcwake: add --dry-run option

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/rtcwake.8 b/sys-utils/rtcwake.8
index 999b678632fc6380ce400c3d9ddd162ca1c0a296..16c05719d889231a245a28deaa678f0b46b1f65a 100644 (file)
--- a/sys-utils/rtcwake.8
+++ b/sys-utils/rtcwake.8
@@ -21,7 +21,7 @@
 rtcwake - enter a system sleep state until specified wakeup time
 .SH SYNOPSIS
 .B rtcwake
-.RB [ \-hvVlua ]
+.RB [ \-hvVluan ]
 .RB [ \-d
 .IR device ]
 .RB [ \-m
@@ -52,11 +52,15 @@ Display a short help message that shows how to use the program.
 \fB-V\fP | \fB--version\fP
 Displays version information and exists.
 .TP
+\fB-n\fP | \fB--dry-run\fP
+This option does everything but actually setup alarm, suspend system or wait 
+for the alarm.
+.TP
 \fB-a\fP | \fB--auto\fP
 Reads the clock mode (whether the hardware clock is set to UTC or local time)
 from \fI/etc/adjtime\fP. That's the location where the
 .BR hwclock (8)
-stores that information.
+stores that information. This is the default.
 .TP
 \fB-l\fP | \fB--local\fP
 Assumes that the hardware clock is set to local time, regardless of the

diff --git a/sys-utils/rtcwake.c b/sys-utils/rtcwake.c
index 344fed76ba721e46873be08183c9e43b76e71d3c..83a5d10ec302cac98c1b87d2fcff366e16f54d9f 100644 (file)
--- a/sys-utils/rtcwake.c
+++ b/sys-utils/rtcwake.c
@@ -62,10 +62,12 @@ enum ClockMode {
 };
 
 static unsigned                verbose;
+static unsigned                dryrun;
 enum ClockMode         clock_mode = CM_AUTO;
 
 static struct option long_options[] = {
        {"auto",        no_argument,            0, 'a'},
+       {"dry-run",     no_argument,            0, 'n'},
        {"local",       no_argument,            0, 'l'},
        {"utc",         no_argument,            0, 'u'},
        {"verbose",     no_argument,            0, 'v'},
@@ -82,6 +84,7 @@ static void usage(int retval)
 {
        printf(_("usage: %s [options]\n"
                "    -d | --device <device>    select rtc device (rtc0|rtc1|...)\n"
+               "    -n | --dry-run            does everything, but suspend\n"
                "    -l | --local              RTC uses local timezone\n"
                "    -m | --mode               standby|mem|... sleep mode\n"
                "    -s | --seconds <seconds>  seconds to sleep\n"
@@ -214,8 +217,9 @@ static int setup_alarm(int fd, time_t *wakeup)
        wake.time.tm_isdst = -1;
 
        wake.enabled = 1;
+
        /* First try the preferred RTC_WKALM_SET */
-       if (ioctl(fd, RTC_WKALM_SET, &wake) < 0) {
+       if (!dryrun && ioctl(fd, RTC_WKALM_SET, &wake) < 0) {
                wake.enabled = 0;
                /* Fall back on the non-preferred way of setting wakeups; only
                * works for alarms < 24 hours from now */
@@ -246,8 +250,10 @@ static void suspend_system(const char *suspend)
                return;
        }
 
-       fprintf(f, "%s\n", suspend);
-       fflush(f);
+       if (!dryrun) {
+               fprintf(f, "%s\n", suspend);
+               fflush(f);
+       }
 
        /* this executes after wake from suspend */
        fclose(f);
@@ -308,7 +314,7 @@ int main(int argc, char **argv)
 
        progname = basename(argv[0]);
 
-       while ((t = getopt_long(argc, argv, "ahd:lm:s:t:uVv",
+       while ((t = getopt_long(argc, argv, "ahd:lm:ns:t:uVv",
                                        long_options, NULL)) != EOF) {
                switch (t) {
                case 'a':
@@ -347,6 +353,10 @@ int main(int argc, char **argv)
                                progname, optarg);
                        usage(EXIT_FAILURE);
 
+               case 'n':
+                       dryrun = 1;
+                       break;
+
                        /* alarm time, seconds-to-sleep (relative) */
                case 's':
                        t = atoi(optarg);
@@ -486,11 +496,13 @@ int main(int argc, char **argv)
                arg[i++] = "now";
                arg[i]   = NULL;
 
-               execv(arg[0], arg);
+               if (!dryrun) {
+                       execv(arg[0], arg);
 
-               fprintf(stderr, _("%s: unable to execute %s: %s\n"),
+                       fprintf(stderr, _("%s: unable to execute %s: %s\n"),
                                progname, _PATH_SHUTDOWN, strerror(errno));
-               rc = EXIT_FAILURE;
+                       rc = EXIT_FAILURE;
+               }
 
        } else if (strcmp(suspend, "on") == 0) {
                unsigned long data;
@@ -498,15 +510,17 @@ int main(int argc, char **argv)
                if (verbose)
                        printf(_("suspend mode: on; reading rtc\n"));
 
-               do {
-                       t = read(fd, &data, sizeof data);
-                       if (t < 0) {
-                               perror(_("rtc read"));
-                               break;
-                       }
-                       if (verbose)
-                               printf("... %s: %03lx\n", devname, data);
-               } while (!(data & RTC_AF));
+               if (!dryrun) {
+                       do {
+                               t = read(fd, &data, sizeof data);
+                               if (t < 0) {
+                                       perror(_("rtc read"));
+                                       break;
+                               }
+                               if (verbose)
+                                       printf("... %s: %03lx\n", devname, data);
+                       } while (!(data & RTC_AF));
+               }
 
        } else {
                if (verbose)
@@ -515,7 +529,7 @@ int main(int argc, char **argv)
                suspend_system(suspend);
        }
 
-       if (ioctl(fd, RTC_AIE_OFF, 0) < 0)
+       if (!dryrun && ioctl(fd, RTC_AIE_OFF, 0) < 0)
                perror(_("disable rtc alarm interrupt"));
 
        close(fd);