NAME
            NL::File::Lock - Extended file locking (based on lockfiles)

VERSION
            This documentation refers to NL::File::Lock version 0.2.

INSTALLATION
            To install this module type the following:

            perl Makefile.PL
            make
            make test
            make install

SYNOPSIS
            use NL::File::Lock;

            my $filename = 'test_file.txt';

            # Writing all lockfiles to '/tmp' directory:
            &NL::File::Lock::init('/tmp');
            # If no 'NL::File::Lock::init' called - all lock files
            # will be at the same directorys as files

            # ---
            # Lock for writing (only one process can write)
            # 'timeout' - time to wail lock
            # 'time_sleep' - time to sleep between locking retrys
            if (&NL::File::Lock::lock_write($filename, { 'timeout' => 10, 'time_sleep' => 0.1 } )) {
                    # File locked

                    # ... code ...

                    &NL::File::Lock::unlock($filename);
            }
            else {
                    # Unable to lock file
            }

            # ---
            # Lock for reading (many processes can read)
            # 'timeout' - time to wail lock
            # 'time_sleep' - time to sleep between locking retrys
            if (&NL::File::Lock::lock_read($filename, { 'timeout' => 10, 'time_sleep' => 0.1 } )) {
                    # File locked

                    # ... code ...

                    &NL::File::Lock::unlock($filename);
            }
            else {
                    # Unable to lock file
            }

DESCRIPTION
            This module is used to powerful, easy and portable file locking.

EXAMPLES
            # ---
            # Lock for writing (only one process can write)
            my $filename = 'test_file.txt';
            # 'timeout' - time to wail lock
            # 'time_sleep' - time to sleep between locking retrys
            if (&NL::File::Lock::lock_write($filename, { 'timeout' => 10, 'time_sleep' => 0.1 } )) {
                    print "+Locked EX (write)...\n";
                    sleep(5);
                    &NL::File::Lock::unlock_not_unlink($filename);
                    print "-UnLocked for some time...\n";
                    sleep(5);
                    if (&NL::File::Lock::lock_write($filename, { 'timeout' => 10, 'time_sleep' => 0.1 } )) {
                            print "+Locked EX (write)...\n";
                            sleep(5);
                            &NL::File::Lock::unlock($filename);
                            print "-UnLocked forever...\n";
                            sleep(5);
                    }
                    else { print "Unable to lock EX (write) again...\n"; }
            }
            else { print "Unable to lock EX (write)...\n"; }

            # ---
            # Lock for reading (many processes can read)
            my $filename = 'test_file.txt';
            # 'timeout' - time to wail lock
            # 'time_sleep' - time to sleep between locking retrys
            if (&NL::File::Lock::lock_read($filename, { 'timeout' => 10, 'time_sleep' => 0.1 } )) {
                            print "+Locked SH (read)...\n";
                            sleep(5);
                            &NL::File::Lock::unlock_not_unlink($filename);
                            print "-UnLocked for some time...\n";
                            sleep(5);
                            if (&NL::File::Lock::lock_read($filename, { 'timeout' => 10, 'time_sleep' => 0.1 } )) {
                                    print "+Locked SH (read)...\n";
                                    sleep(5);
                                    &NL::File::Lock::unlock($filename);
                                    print "-UnLocked forever...\n";
                                    sleep(5);
                            }
                            else { print "Unable to lock SH (read) agian...\n"; }
            }
            else { print "Unable to lock SH (read)...\n"; }
 
AUTHOR
            Nickolay Kovalev, http://resume.nickola.ru
            Email: nickola_code@nickola.ru

