my $timeout = 5;
 eval {
        local $SIG{ALRM} = sub { die "alarm\n" }; 
        alarm $timeout;
        my @file_list = `ls user/test/`;       
        my $file;
        my @file_list;
        foreach $file(@file_list){
        print "$file\n";
         }
        alarm 0;
    };
    if ($@) {
        die unless $@ eq "alarm\n";   # propagate unexpected errors
        # timed out
    }
    else {
        # didn't
    }