Here's an improved version.
- The old version always waited for at least the timeout period, even if the command completed early.
This one returns as soon as the external command terminates.
- The old version returned nothing if the process timed out.
This version will return as much as was available before the process was killed.
- It also addresses a potential "Uninitialised" warning if the system is heavily loaded and the thread takes a while to start.
If the thread or process was slow starting due to system load or other factors, the old version could try to use $pid before it was set. This corrects that error.
#! perl -slw
our $N ||= 11;
my $TIMEOUT = 10;
my $extApp = q[ perl -lwe"$|++; print $_ and sleep 1 for 1 .. $ARGV
my @results :shared;
my $pid :shared;
$pid = open my $fh, "$extApp $N |" or die "$!, $^E";
push @results, $_ while <$fh>;
sleep 1 until $pid;
sleep 1 while kill 0, $pid and $TIMEOUT--;
kill 3, $pid and warn 'Command timed out' if $TIMEOUT;
print "command return \n'@results'";
Command timed out at C:\test\timeoutcmd.pl line 21.
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