use Data::Dumper;

sub file_read_firstline {
    my ($filename) = @_;

    my $fh = IO::File->new ($filename, "r");
    return undef if !$fh;
    my $res = <$fh>;
    chomp $res if $res;
    $fh->close;
    return $res;
}

sub read_proc_pid_stat {
    my $pid = shift;

    my $statstr = file_read_firstline("/proc/$pid/stat");

    if ($statstr && $statstr =~ m/^$pid \(.*\) (\S) (-?\d+) -?\d+ -?\d+ -?\d+ -?\d+ \d+ \d+ \d+ \d+ \d+ (\d+) (\d+) (-?\d+) (-?\d+) -?\d+ -?\d+ -?\d+ 0 (\d+) (\d+) (-?\d+) \d+ \d+ \d+ \d+ \d+ \d+ \d+ \d+ \d+ \d+ \d+ \d+ \d+ -?\d+ -?\d+ \d+ \d+ \d+/) {
	print "$statstr\n";
	print "$7\n";
	print ref \$7, "\n";
	return {
	    status => $1,
	    ppid => $2,
	    utime => $3,
	    stime => $4,
	    starttime => $7,
	    vsize => $8,
	    rss => $9 * 4096,
	};
    }

    return undef;
}

sub test {
	my %res = read_proc_pid_stat(1);
	print "$res->{starttime}";
	while (my ($k,$v)=each %res){print "$k $v\n"};
	print "@{[$res]}\n";
	foreach my $key ( keys %res ) { 
		print $key, " => ", $res->{$key},"\n";
	}
}

test()