metronome

[Jan Stary]

By default, metronome (audio/metronome)
does scroll stdin lines to stdout in sync with the beat.

The problem is, it waits for fgetln(stdin, &len),
so the simple and expected

        $ metronome

issues just one beep and waits for a line to read on stdin.
The next beep happens upon an <enter>. I think it's unexpected behaviour.
It works fine though with 'yes | metronome' or 'metronome < /dev/null'.

Also, the manpage wording is not very clear:

        -F      Display lines from stdin on stdout, one line each beat.
                By default, 1/10th.

1/10 of what? One line per beat is one line per beat.
(Or I am missing something.)

It would IMHO be a better default to ignore stdin, and just keep the beat.
The diff bellow does that (and adds one return-value check while at it).


        Jan



diff -rup ../metronome-1/metronome.6 ./metronome.6
--- ../metronome-1/metronome.6  Sun Aug 19 11:46:16 2012
+++ ./metronome.6       Mon Mar 18 20:48:25 2013
@@ -51,7 +51,7 @@ Make each audio tick a fraction of the total interval 
 .Ar number .
 .It Fl F
 Display lines from stdin on stdout, one line each beat.
-By default, 1/10th.
+By default, stdin is ignored.
 .It Fl s Ar freq
 Set audio output sampling frequency to
 .Ar freq .
diff -rup ../metronome-1/metronome.c ./metronome.c
--- ../metronome-1/metronome.c  Sun Mar 17 14:11:12 2013
+++ ./metronome.c       Mon Mar 18 20:47:01 2013
@@ -123,7 +123,7 @@ main(int argc, char *argv[])
 
        int ch;
 
-       /* parameters, then default values */
+       d.scroll = 0;
        while ((ch = getopt(argc, argv, "b:f:Fs:t:B:T:")) != -1) {
                switch (ch) {
                case 'b':
@@ -190,7 +190,8 @@ main(int argc, char *argv[])
                d.delta = d.increment;
                sio_onmove(io, cb, &d);
        }
-       sio_start(io);
+       if (sio_start(io) == 0)
+               bail("sio_start");
        play(io, &par, bpm, frac, tone, beats, tone2);
        /*NOTREACHED*/
 }