rtcwake: fix incorrect (reversed) rtc/sys adjuestment; code shrink

function                                             old     new   delta
rtcwake_main                                         482     462     -20

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 32 insertions, 23 deletions

diff --git a/util-linux/rtcwake.c b/util-linux/rtcwake.c
index 735a29822..33cdbfad4 100644
--- a/util-linux/rtcwake.c
+++ b/util-linux/rtcwake.c
@@ -51,7 +51,6 @@
 
 #define SYS_RTC_PATH   "/sys/class/rtc/%s/device/power/wakeup"
 #define SYS_POWER_PATH "/sys/power/state"
-#define DEFAULT_MODE   "standby"
 
 static NOINLINE bool may_wakeup(const char *rtcname)
 {
@@ -122,17 +121,16 @@ static NOINLINE void setup_alarm(int fd, time_t *wakeup, time_t rtc_time)
 int rtcwake_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int rtcwake_main(int argc UNUSED_PARAM, char **argv)
 {
-        time_t rtc_time;
-
         unsigned opt;
         const char *rtcname = NULL;
-        const char *suspend;
+        const char *suspend = "standby";
         const char *opt_seconds;
         const char *opt_time;
 
+        time_t rtc_time;
         time_t sys_time;
-        time_t alarm_time = 0;
-        unsigned seconds = 0;
+        time_t alarm_time = alarm_time;
+        unsigned seconds = seconds; /* for compiler */
         int utc = -1;
         int fd;
 
@@ -148,6 +146,8 @@ int rtcwake_main(int argc UNUSED_PARAM, char **argv)
                 ;
         applet_long_options = rtcwake_longopts;
 #endif
+        /* Must have -s or -t, exclusive */
+        opt_complementary = "s:t:s--t:t--s";
         opt = getopt32(argv, "alud:m:s:t:", &rtcname, &suspend, &opt_seconds, &opt_time);
 
         /* this is the default
@@ -156,17 +156,17 @@ int rtcwake_main(int argc UNUSED_PARAM, char **argv)
         */
         if (opt & (RTCWAKE_OPT_UTC | RTCWAKE_OPT_LOCAL))
                 utc = opt & RTCWAKE_OPT_UTC;
-        if (!(opt & RTCWAKE_OPT_SUSPEND_MODE))
-                suspend = DEFAULT_MODE;
-        if (opt & RTCWAKE_OPT_SECONDS)
+        if (opt & RTCWAKE_OPT_SECONDS) {
                 /* alarm time, seconds-to-sleep (relative) */
-                seconds = xatoi(opt_seconds);
-        if (opt & RTCWAKE_OPT_TIME)
+                seconds = xatou(opt_seconds);
+        } else {
+                /* RTCWAKE_OPT_TIME */
                 /* alarm time, time_t (absolute, seconds since 1/1 1970 UTC) */
-                alarm_time = xatol(opt_time);
-
-        if (!alarm_time && !seconds)
-                bb_error_msg_and_die("must provide wake time");
+                if (sizeof(alarm_time) <= sizeof(long))
+                        alarm_time = xatol(opt_time);
+                else
+                        alarm_time = xatoll(opt_time);
+        }
 
         if (utc == -1)
                 utc = rtc_adjtime_is_utc();
@@ -177,8 +177,9 @@ int rtcwake_main(int argc UNUSED_PARAM, char **argv)
         /* this RTC must exist and (if we'll sleep) be wakeup-enabled */
         fd = rtc_xopen(&rtcname, O_RDONLY);
 
-        if (strcmp(suspend, "on") && !may_wakeup(rtcname))
-                bb_error_msg_and_die("%s not enabled for wakeup events", rtcname);
+        if (strcmp(suspend, "on") != 0)
+                if (!may_wakeup(rtcname))
+                        bb_error_msg_and_die("%s not enabled for wakeup events", rtcname);
 
         /* relative or absolute alarm time, normalized to time_t */
         sys_time = time(NULL);
@@ -188,21 +189,29 @@ int rtcwake_main(int argc UNUSED_PARAM, char **argv)
                 rtc_time = rtc_tm2time(&tm_time, utc);
         }
 
-
-        if (alarm_time) {
-                if (alarm_time < sys_time)
+        if (opt & RTCWAKE_OPT_TIME) {
+                /* Correct for RTC<->system clock difference */
+                alarm_time += rtc_time - sys_time;
+                if (alarm_time < rtc_time)
+                        /*
+                         * Compat message text.
+                         * I'd say "RTC time is already ahead of ..." instead.
+                         */
                         bb_error_msg_and_die("time doesn't go backward to %s", ctime(&alarm_time));
-                alarm_time += sys_time - rtc_time;
         } else
                 alarm_time = rtc_time + seconds + 1;
-        setup_alarm(fd, &alarm_time, rtc_time);
 
+        setup_alarm(fd, &alarm_time, rtc_time);
         sync();
+#if 0 /*debug*/
+        printf("sys_time: %s", ctime(&sys_time));
+        printf("rtc_time: %s", ctime(&rtc_time));
+#endif
         printf("wakeup from \"%s\" at %s", suspend, ctime(&alarm_time));
         fflush_all();
         usleep(10 * 1000);
 
-        if (strcmp(suspend, "on"))
+        if (strcmp(suspend, "on") != 0)
                 xopen_xwrite_close(SYS_POWER_PATH, suspend);
         else {
                 /* "fake" suspend ... we'll do the delay ourselves */