NAME

File::LineEdit - Small utility for editing each line of a file

SYNOPSIS

 # object interface
 my $le = File::LineEdit->new('myfile.txt');
 foreach my $line (@$le)
        {$line =~ s|foo|bar|}
 
 # tied array interface
 my (@le);
 tie @le, 'File::LineEdit::Tie', 'myfile.txt';
 foreach my $line (@le)
        {$line =~ s|foo|bar|}
 untie @le;

INSTALLATION

File::LineEdit can be installed with the usual routine:

        perl Makefile.PL
        make
        make test
        make install

You can also just copy LineEdit.pm into the File/ directory of one of your library trees.

DESCRIPTION

File::LineEdit is just a small utility to simplify modiyfying a file line-by-line. It performs the boring tasks of slurping in the file, chomping each line (if you want it to), and then, after changes are made, writing the data back to the file.

The basic usage is quite simple: instantiate a File::LineEdit object, loop through the object as if it were an array, modifying each line however you want. When the object falls out of scope, it automatically writes the modified lines back to the file. Here's a simple example (actually, the same example used in the synopsis above, this time with a little more documentation):

 # instantiate a File::LineEdit object, passing in 
 # the path to the file as the only required argument.
 my $le = File::LineEdit->new('myfile.txt');
 
 # loop through the lines in the file
 foreach my $line (@$le) {
     
     # change the line in some way
     $line =~ s|foo|bar|;
 
 }
 
 # The data is saved back to the file
 # automatically when the object falls
 # out of scope.  No need for an
 # explicit save.

There are a few variations on this theme.

Explicit save

By default, LineEdit objects save their line data back

If you just somehow don't trust the concept of saving on object destruction, you can tell your LineEdit object to explicitly save:

 $le->save;

If you don't want the object to automatically save on destruction, add the autosave argument to the instantiation params:

 my $le = File::LineEdit->new('myfile.txt', autosave=>0);

Saving to a different file

You might prefer to slurp data in from one file, then save to another. To do so, just add the savepath parameter to the new() call. For example, the following command slurps from source.txt and saves to target.txt:

 my $le = File::LineEdit->new('source.txt', savepath=>'target.txt');

You can also set the save path after object creation by setting the savepath property:

Automatic line chomping

By default, LineEdit automatically chomps the end of each line when it slurps in the data from the file. If you prefer to keep your lines unchomped then add an autochomp argument to the instantiation params:

 my $le = File::LineEdit->new('myfile.txt', autochomp=>0);

TIED ARRAY INTERFACE

You can also use File::LineEdit as a tied array. Just tie your array to File::LineEdit::Tie, passing the file path as the only argument:

 # tied array interface
 my (@le);
 tie @le, 'File::LineEdit::Tie', 'myfile.txt';
 foreach my $line (@le)
        {$line =~ s|foo|bar|}
 untie @le;

SIMILAR MODULES

There are a couple modules on CPAN that provide similar functionality. File::Searcher provides the ability to do regular expression based search and replaces on groups of files. File::Data provides several ways to slurp in, modify, and write files. File::Data also uses regular expressions for searching and replacing. Be sure to look at both of those modules if you are interested in simplified modification of files.

File::LineEdit differs from File::Searcher and File::Data in that File::LineEdit focuses on line-based edits. The object of File::LineEdit is to provide a simplified manner for looking at and modifying files one line at a time.

TERMS AND CONDITIONS

Copyright (c) 2003 by Miko O'Sullivan. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. This software comes with NO WARRANTY of any kind.

AUTHORS

Miko O'Sullivan miko@idocs.com

Useful contribution by Dan Brook.

VERSION

Version 1.00 June 27, 2003

Initial release

Version 1.11 June 30, 2003

Added overloading so that you can reference the LineEdit object itself as if it were a reference to an array. That was Dan Brook's idea. Thanks Dan!

Then I took Dan's idea a step further and added the ability to tie File::LineEdit to an array using File::LineEdit::Tie.

Version 1.12 July 3, 2003

Added ability to set the object to save to a different file than the file the data was slurped from. Also tidied up documentation a little.

cpanm File::LineEdit

perl -MCPAN -e shell
install File::LineEdit