watch: support fractional -n SEC

function                                             old     new   delta
watch_main                                           212     232     +20

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

2 files changed, 14 insertions, 5 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 3366df30f..7a1e13875 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1040,9 +1040,11 @@ uint16_t xatou16(const char *numstr) FAST_FUNC;
 #if ENABLE_FLOAT_DURATION
 typedef double duration_t;
 void sleep_for_duration(duration_t duration) FAST_FUNC;
+#define DURATION_FMT "f"
 #else
 typedef unsigned duration_t;
 #define sleep_for_duration(duration) sleep(duration)
+#define DURATION_FMT "u"
 #endif
 duration_t parse_duration_str(char *str) FAST_FUNC;
 
diff --git a/procps/watch.c b/procps/watch.c
index dbe427aad..059eb1dda 100644
--- a/procps/watch.c
+++ b/procps/watch.c
@@ -22,7 +22,7 @@
 //usage:       "[-n SEC] [-t] PROG ARGS"
 //usage:#define watch_full_usage "\n\n"
 //usage:       "Run PROG periodically\n"
-//usage:     "\n        -n      Loop period in seconds (default 2)"
+//usage:     "\n        -n SEC  Loop period (default 2)"
 //usage:     "\n        -t      Don't print header"
 //usage:
 //usage:#define watch_example_usage
@@ -51,8 +51,9 @@
 int watch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int watch_main(int argc UNUSED_PARAM, char **argv)
 {
+        duration_t period;
+        char *period_str = (char*) "2";
         unsigned opt;
-        unsigned period = 2;
         unsigned width, new_width;
         char *header;
         char *cmd;
@@ -65,7 +66,7 @@ int watch_main(int argc UNUSED_PARAM, char **argv)
 
         // "+": stop at first non-option (procps 3.x only); -n NUM
         // at least one param
-        opt = getopt32(argv, "^+" "dtn:+" "\0" "-1", &period);
+        opt = getopt32(argv, "^+" "dtn:" "\0" "-1", &period_str);
         argv += optind;
 
         // watch from both procps 2.x and 3.x does concatenation. Example:
@@ -74,6 +75,7 @@ int watch_main(int argc UNUSED_PARAM, char **argv)
         while (*++argv)
                 cmd = xasprintf("%s %s", cmd, *argv); // leaks cmd
 
+        period = parse_duration_str(period_str);
         width = (unsigned)-1; // make sure first time new_width != width
         header = NULL;
         while (1) {
@@ -88,7 +90,12 @@ int watch_main(int argc UNUSED_PARAM, char **argv)
                         if (new_width != width) {
                                 width = new_width;
                                 free(header);
-                                header = xasprintf("Every %us: %-*s", period, (int)width, cmd);
+                                header = xasprintf("Every"
+                                        " %"IF_FLOAT_DURATION(".1")DURATION_FMT"s:"
+                                        " %-*s",
+                                        period,
+                                        (int)width, cmd
+                                );
                         }
                         if (time_len < width) {
                                 strftime_YYYYMMDDHHMMSS(
@@ -106,7 +113,7 @@ int watch_main(int argc UNUSED_PARAM, char **argv)
                 // and does not allow it to overflow the screen
                 // (taking into account linewrap!)
                 system(cmd);
-                sleep(period);
+                sleep_for_duration(period);
         }
         return 0; // gcc thinks we can reach this :)
 }