VCP::Patch - Apply the (almost) unified diffs used in RevML
use VCP::Patch ; vcp_patch( $source_file_name, $result_file_name, $patch_file_name ) ;
Creates the result file by applying the patch to the source file. Obliterates the result file even if the patch fails.
The patches are in a "unified diff" format, but without the filename headers (these are passed as other data fields in VCP and the actual filenames are just working files and are not important). Some example patches:
For a one line file:
@@ -1 +1 @@ -a/deeply/buried/file, revision 1, char 0x01="<char code="0x01" />" +a/deeply/buried/file, revision 2, char 0x09=" "
For a several line file with multiple changes:
Here are the source and result files side-by-side:
Source Result ====== ====== 1 1 2 2 3 3 4 4 5d 5a 6 6 7 7 8 8 9 9 10 9a 11 10 11d 11 12 12 13 13
The "patch" to transform the source in to the result can be expressed in several ways, depending on the amount of context. VCP requires no context since the result is checked with an MD5 checksum. Context is, however, sometimes used to make the RevML a bit more human readable, though this can vary.
diff -U 0
@@ -5 +5 @@ -5d +5a @@ -9,0 +10 @@ +9a @@ -12 +12,0 @@ -11d
diff -U 1
--- A Sat Aug 25 00:05:26 2001 +++ B Sat Aug 25 00:05:26 2001 @@ -4,3 +4,3 @@ 4 -5d +5a 6 @@ -9,5 +9,5 @@ 9 +9a 10 11 -11d 12
diff -U 3 ...
diff -u ...
--- A Sat Aug 25 00:05:26 2001 +++ B Sat Aug 25 00:05:26 2001 @@ -2,13 +2,13 @@ 2 3 4 -5d +5a 6 7 8 9 +9a 10 11 -11d 12 13
Takes a patch file name, a source file name, and a result file name and performs the patch. Called from VCP::Source::revml to reconstitute revisions given by delta records.
Will die on error, always returns true.
Copyright 2000, Perforce Software, Inc. All Rights Reserved.
This module and the VCP package are licensed according to the terms given in the file LICENSE accompanying this distribution, a copy of which is included in vcp.
Sean McCune <sean@sean-mccune.com>
2 POD Errors
The following errors were encountered while parsing the POD:
'=item' outside of any '=over'
You forgot a '=back' before '=head1'
To install VCP, copy and paste the appropriate command in to your terminal.
cpanm
cpanm VCP
CPAN shell
perl -MCPAN -e shell install VCP
For more information on module installation, please visit the detailed CPAN module installation guide.