olegwtf · November 11, 2016 10:42
diff --git a/gistfile1.pm b/gistfile1.pm
 package ScriptLock;

 use strict;
 use FindBin;
 use Fcntl ':flock';

 my $fh;

 sub import {
    return if $fh;
    
    open $fh, '<', "$FindBin::Bin/$FindBin::Script"
        or die "open: $!";
    flock $fh, LOCK_EX|LOCK_NB
        or die "flock: $!";
 }

 1;
	package ScriptLock;

	use strict;
	use FindBin;
	use Fcntl ':flock';

	my $fh;

	sub import {
	return if $fh;

	open $fh, '<', "$FindBin::Bin/$FindBin::Script"
	or die "open: $!";
	flock $fh, LOCK_EX\|LOCK_NB
	or die "flock: $!";
	}

	1;