1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
#!/usr/bin/env perl
use strict;
use warnings FATAL => 'all';
use Time::HiRes qw(sleep time);
if ( !@ARGV || @ARGV < 2 ) {
print STDERR "Usage: wait-to-exec WAIT EXEC [RUNTIME [INTERVAL]]\n",
"When the WAIT script exits 0, execute the EXEC script.\n";
exit 1;
}
my ($wait, $exec, $runtime, $interval) = @ARGV;
$runtime ||= 1.0;
$interval ||= 0.1;
#warn "wait: $wait\n";
#warn "exec: $exec\n";
my $t_start = time;
while ( time - $t_start < $runtime ) {
if ( exit_status($wait) ) {
sleep $interval;
}
else {
# exec does not return; this script becomes the exec process.
exec($exec);
}
}
warn "Never observed wait condition";
exit 1;
sub exit_status {
my ($wait) = @_;
system($wait);
# Like grep, exit status 0 means "match found", so stop waiting.
my $exit_status = $? >> 8;
return $exit_status;
}
|
