Introduction

Patcher is a tool for quick creation of patches against a project source tree. Patcher functionality resembles a lightweight version control system. It has no repository, and only controls differences between a pristine version and a working copy.

Why

The idea for developing patcher happened during the development of Conectiva Linux. More specifically, when we had to fix some of the packages to compile with GCC 3.2. Fixing a package which is not compiling due to some issue in the environment is a commonly-occuring task in a Linux distribution's development. At the same time, the source code of projects must be kept intact, forcing developers to work with individual patches to change some behavior in the project. Patcher makes it very easy to work in such environments.

Using patcher

Here's a very simple succession of commands, with explanations.

Unpack the project:

$ tar xzf project-1.0.tar.gz 
$ cd project-1.0 

Create patcher structures for the project:

$ ptr start 

Change the project somehow:

$ cd src 
$ vi project.c 

Check what changes have been made so far:

$ ptr status 
?   project.o 
M   project.c 
$ ptr diff project.c 
... 

Extract a patch for these changes:

$ cd ../.. 
$ ptr diff project-1.0 > project-1.0-changes.patch 

Remove patcher structures from the project:

$ ptr stop project-1.0 

Using patcher with large trees

When using patcher with a large source tree you can choose to include files under patcher control on demand. To do that, first run the start command with the -n parameter:

$ tar xzf project-1.0.tar.gz 
$ cd project-1.0 
$ ptr start -n 

Then, whenever you want to edit a file, add it to patcher control first:

$ cd src 
$ ptr add project.c 
A    project.c 
$ vi project.c 

When you're done, extract a patch for these changes as usual:

$ cd ../.. 
$ ptr diff project-1.0 > project-1.0-changes.patch 

Screenshot

This is command-line interface (CLI) software, so there's no real screenshot. Here is the output of ptr --help to get a feeling of it.

Usage: ptr COMMAND [COMMAND ARGUMENTS] 
 
Available commands: 
    start     Create patcher structures 
    stop      Remove patcher structures 
    diff      Run diff between working copies and pristine versions 
    status    Check entries status 
    revert    Revert working copy to pristine version 
    ignore    Ignore given entries when doing certain operations 
    unignore  Revert effect of ignore command 
    add       Add given entries to patcher control 
    remove    Remove given entries from patcher control 
 
Run "ptr COMMAND --help" for more information. 

Download

Available files:

• patcher-0.6.tar.gz

Related work

For a more full-featured "in place" versioning control, check Bazaar.

For working with stacked patches, check quilt

License

Patcher is released under the GPL. Read the LICENSE file for more information.

Author

Gustavo Niemeyer <gustavo@niemeyer.net>

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CategoryProject