Add interval timer snippet

Signed-off-by: Florian Pritz <bluewind@xinu.at>

1 files changed, 22 insertions, 0 deletions

diff --git a/interval-timer.pl b/interval-timer.pl
new file mode 100644
index 0000000..f7bb247
--- /dev/null
+++ b/interval-timer.pl
@@ -0,0 +1,22 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+
+use Time::HiRes qw(sleep time gettimeofday);
+use POSIX qw(fmod);
+
+my $interval = 1;
+
+# enable autoflush
+$| = 1;
+
+while (1) {
+	my ($time, $usec) = gettimeofday();
+	# this also works, but fmod below is more readable
+	#my $sleep_time = ($interval - ($time % $interval + 1)) + (1000_000 - $usec) / 1000_000;
+	my $sleep_time = $interval - fmod(time(), $interval);
+	printf "current time = %s (%s, %s), sleeping for %s\n", time(), $time, $usec, $sleep_time;
+	my $slept = sleep($sleep_time);
+	printf "new time = %s after sleeping for %s\n", time(), $slept;
+	printf "%s\n", time();
+}