Created
January 10, 2015 10:04
-
-
Save mklooss/7a468887e777f7342ed7 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#!/usr/bin/perl | |
use strict ; | |
use warnings ; | |
use constant DEBUG => 0 ; | |
my $adjtimex = q{/sbin/adjtimex} ; | |
open my $cmdpipe, "$adjtimex --print |" ; | |
if (not defined $cmdpipe) { | |
die "Hell, cannot read from $adjtimex pipe" ; | |
} | |
my $status ; | |
while (my $line = <$cmdpipe>) { | |
my ($keyword,$value) = ($line =~ m/^\s*(.+): (.+)$/) ; | |
next unless $keyword eq q{status} ; | |
$status = $value ; | |
last ; | |
} | |
if (not defined $status) { | |
die "Cannot read status from $adjtimex" ; | |
} | |
# We try to detect if a leap second is inserted (16) or deleted (32) | |
# We AND the status string with 48 (32+16) and we expect $leap to be | |
# either 0 (those bits are down), or 16 (leap second inserted), or | |
# 32 (leap second removed). Theoretically, we could also get 48, but | |
# that would mean that we are both inserting and removing a leap second | |
# at the same time, which is illogical. | |
my $leap = $status & 48 ; | |
if ($leap == 0) { | |
# No leap set, we "fail" out | |
exit 1 ; | |
} | |
if ($leap == 16 or $leap == 32) { | |
# Leap second inserted (16) or deleted (32): we must reset that bit | |
$status -= $leap ; | |
system($adjtimex,'--status',$status) ; | |
exit 0 ; | |
} | |
die "Leap bits are set to $leap, which is illogical" ; |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment