NAME

Launcher::Cascade::FileReader::Seekable - a filereader that memorizes its position between reads.

SYNOPSIS

    use Launcher::Cascade::FileReader::Seekable;

    my $f = new Launcher::Cascade::FileReader -path => ... ;

    my $fh1 = $f->open();
    my $line1 = <$fh1>; # first line
    $f->close();

    # later, in a nearby piece of code

    my $fh2 = $f->open(); # different filehandle
    my $line2 = <$fh2>; # next line

DESCRIPTION

Launcher::Cascade::FileReader::Seekable inherits from Launcher::Cascade::FileReader but keeps in memory the position where it was at when the filehandle is closed. Subsequent calls to open() will perform the necessary operations to resume reading where it last stopped, be it when reading a local file, or a remote file through ssh.

Attributes

position

Methods

close

Stores the filehandle's position in the position() attribute, then closes the filehandle.

open

Opens the file (locally or remotely), seeks to the desired position() and returns a filehandle.

BUGS AND CAVEATS

• perl has to be in a directory mentioned in the PATH environment variable on the remote host, because the seek operation on remote files is performed with a Perl one-liner.

• The memorization of the position is performed only when closing the filehandle through the close() method of Launcher::Cascade::FileReader::Seekable, not when closing the filehandle directly:

      my $fh = $f->open();
      ... # do something with it
  
      $f->close();   # right: position() is updated
      close $fh;     # wrong: position() is *not* updated

SEE ALSO

Launcher::Cascade::FileReader

AUTHOR

Cédric Bouvier <cbouvi@cpan.org>

COPYRIGHT & LICENSE

Copyright (C) 2006 Cédric Bouvier, All Rights Reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.