NAME¶

SVN::Web::DiffParser - Parse patch files containing unified and standard diffs

NOTE¶

This is Text::Diff::Parser, plus some local bug fixes that were exposed by use with SVN::Web. For more details about Text::Diff::Parser please see CPAN.

SYNOPSIS¶

    use SVN::Web::DiffParser;
    # create the object
    my $parser = SVN::Web::DiffParser->new();
    # With options
    $parser = SVN::Web::DiffParser->new( Simplify=>1, # simplify the diff
                                       Strip=>2 );  # strip 2 directories
    # Create object.  Parse $file
    $parser = SVN::Web::DiffParser->new( $file );
    $parser = SVN::Web::DiffParser->new( File=>$file );
    # Create object.  Parse text
    my $parser = SVN::Web::DiffParser->new( $text );
    $parser = SVN::Web::DiffParser->new( Diff=>$text );
    # parse a file
    $parser->parse_file( $filename );
    # parse a string
    $parser->parse( $text );
    
    # Remove no-change lines.  Combine line substitutions
    $parser->simplify;
    # Find results
    foreach my $change ( $parser->changes ) {
        print "File1: ", $change->filename1;
        print "Line1: ", $change->line1;
        print "File2: ", $change->filename2;
        print "Line2: ", $change->line2;
        print "Type: ", $change->type;
        my $size = $change->size;
        foreach my $line ( 0..($size-1) ) {
            print "Line: ", $change->line( $size );
        }
    }
    # In scalar context, returns the number of changes
    my $n = $parser->changes;
    print "There are $n changes", 
    # Get the changes to a given file
    my @changes = $parser->changes( 'Makefile.PL' );
    # Get list of files changed by the diff
    my @files = $parser->files;

DESCRIPTION¶

"SVN::Web::DiffParser" parses diff files and patches. It allows you to access the changes to a file in a standardized way, even if multiple patch formats are used.

A diff may be viewed a series of operations on a file, either adding, removing or modifying lines of one file (the "from-file") to produce another file (the "to-file"). Diffs are generally produced either by hand with diff, or by your version control system ("cvs diff", "svn diff", ...). Some diff formats, notably unified diffs, also contain null operations, that is lines that

"SVN::Web::DiffParser" currently parses unified diff format and standard diff format.

Unified diffs look like the following.

    --- Filename1 2006-04-12 18:47:22.000000000 -0400
    +++ Filename2 2006-04-12 19:21:16.000000000 -0400
    @@ -1,4 +1,6 @@
     ONE
     TWO
    -THREE
    +honk
     FOUR
    +honk
    +honk

Standard diffs look like the following.

    diff something something.4
    3c3
    < THREE
    ---
    > honk
    4a5,6
    > honk
    > honk

The diff line isn't in fact part of the format but is necessary to find which files the chunks deal with. It is output by "cvs diff" and "svn diff" so that isn't a problem.

METHODS¶

    $parser = SVN::Web::DiffParser->new;
    $parser = SVN::Web::DiffParser->new( $file );
    $parser = SVN::Web::DiffParser->new( $handle );
    $parser = SVN::Web::DiffParser->new( %params );
    $parser = SVN::Web::DiffParser->new( \%params );

    $parser->parse_file( $file );
    $parser->parse_file( $handle );

    $parser->parse( $string );

    %files = $parser->files;

    @changes = $parser->changes;
    $n = $parser->changes;
    @changes = $parser->changes( $file );
    $n = $parser->changes( $file );

CHANGE METHODS¶

The "changes" method returns an array of objects that describe each operation. You may use the following methods to find out details of the operation.

    @lines = $ch->text;
    $line  = $ch->text( $N );

BUGS¶

I'm not 100% sure of standard diff handling.

Missing support for context diffs.

SEE ALSO¶

Text::Diff, Arch, diff.

AUTHOR¶

Philip Gwyn, <gwyn-at-cpan.org>

COPYRIGHT AND LICENSE¶

Copyright (C) 2006 by Philip Gwyn

Copyright (C) 2012 by Dean Hamstead

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.8 or, at your option, any later version of Perl 5 you may have available.