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¶
new¶
$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 );
Object constructor.
- Diff
- String that contains a diff. This diff will be parse before
"new" returns.
- File
- File name or file handle that is parsed before "new"
returns.
- Simplify
- Simplifying a patch involves dropping all null-operations and converting
and remove operation followed by an add operation (or an add followed by a
remove) of the same size on the same lines into a modify operation.
- Strip
- Strip N leading directories from all filenames. Less then useful for
standard diffs produced by "cvs diff", because they don't
contain directory information.
- Verbose
- If true, print copious details of what is going on.
parse_file¶
$parser->parse_file( $file );
$parser->parse_file( $handle );
Read and parse the file or file handle specified. Will "die" if it
fails, returns true on success. Contents of the file may then be accessed with
"changes" and "files".
parse¶
$parser->parse( $string );
Parses the diff present in $string. Will "die" if it fails, returns
true on success. Contents of the file may then be accessed with
"changes" and "files".
files¶
%files = $parser->files;
Fetch a list of all the files that were referenced in the patch. The keys are
original files ("from-file") and the values are the modified files
("to-file").
changes¶
@changes = $parser->changes;
$n = $parser->changes;
@changes = $parser->changes( $file );
$n = $parser->changes( $file );
Return all the operations (array context) or the number of operations in the
patch file. If $file is specified, only returns changes to that file
("from-file" or "to-file").
Elements of the returned array are change objects, as described in "CHANGE
METHODS" below.
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.
type¶
Returns the type of operation, either 'ADD', 'REMOVE', 'MODIFY' or '' (null
operation).
filename1¶
Filename of the "from-file".
filename2¶
Filename of the "to-file".
line1¶
Line in the "from-file" the operation starts at.
line2¶
Line in the "to-file" the operation starts at.
size¶
Number of lines affected by this operation.
text¶
@lines = $ch->text;
$line = $ch->text( $N );
Fetch the text of the line $N if present or all lines of affected by this
operation. For '' (null) and 'REMOVE' operations, these are the lines present
before the operation was done ('from-file'. For 'ADD' and 'MODIFY' operations,
these are the lines present after the operation was done ('to-file'.
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.