在Perl中使用系统cmd时超时

Question

I'm using PSEXEC to run remote process with system($CMD) in perl.

I have a computer (lets call it-#1) that runs system cmd , and another computer (lets call it-#2), which "receives" commands from computer #1.

Sometimes the process in the second computer (#2) gets stuck.

How can I set a timeout to the system cmd in computer #1 that will force-terminate the cmd after several minutes?

---

thanks for the answers, but: i'm tring to do somthing very simple, I have 2 perl files. file#1 that counting seconds 1 to 10. (+print to the screen) file#2-Timeout file that cal file#1 (system command) that should terminate file #1 after 5 sec.

the results...: timeout occurred, but process #1 still running...

file#2

$timeout=5;
eval {
    local $SIG{ALRM} = sub { die "alarm\n" }; # NB: \n required
    alarm $timeout;
    $nread = system('F:\perl1.pl');
    alarm 0;
};
if ($@) {
    die unless $@ eq "alarm\n";   # propagate unexpected errors
    print "process terminated\n";}
else {
    # didn't
}

file#1

$i=0;
while($

    i<10){
    sleep(1);
    $i++;

print "$i\n";
}

CMD window results:

C:\>F:\perl2.pl
1
2
3
4
process terminated

C:\>5
6
7
8
9
10

Answer 1

Let IPC::Run handle that for you.

use IPC::Run qw( run timeout );

run \@cmd, timeout( 120 )
   or die "cat: $?";

Answer 2

You could use alarm in your situation:

If you want to use alarm to time out a system call you need to use an eval / die pair. You can't rely on the alarm causing the system call to fail with $! set to EINTR because Perl sets up signal handlers to restart system calls on some systems. Using eval / die always works, modulo the caveats given in Signals in perlipc .

 eval { local $SIG{ALRM} = sub { die "alarm\\n" }; # NB: \\n required alarm $timeout; $nread = sysread SOCKET, $buffer, $size; alarm 0; }; if ($@) { die unless $@ eq "alarm\\n"; # propagate unexpected errors # timed out } else { # didn't }