Overview
This library is a PHP wrapper around the Git command line tool. 
, (*1)
Its purpose is to provide a readable API that abstracts some of the challenges
of executing Git commands from within a PHP process. Specifically, this library
builds upon the Symfony framework's Process component to execute the Git command
in a way that works across platforms and uses the best-in-breed techniques
available to PHP. This library also provides an SSH wrapper script and API
method for developers to easily specify a private key other than one of the
defaults by using the technique in this thread on StackOverflow.
Finally, various commands are expected to be executed in the directory
containing the working copy. Although this a fairly simple challenge to
overcome, the library handles this transparently so the developer doesn't have
to think about it., (*2)
Usage
use GitWrapper\GitWrapper;
// Initialize the library. If the path to the Git binary is not passed as
// the first argument when instantiating GitWrapper, it is auto-discovered.
require_once 'vendor/autoload.php';
$wrapper = new GitWrapper();
// Optionally specify a private key other than one of the defaults.
$wrapper->setPrivateKey('/path/to/private/key');
// Get a working copy object, clone a repo into `./path/to/working/copy`.
$git = $wrapper->workingCopy('./path/to/working/copy');
$git->clone('git://github.com/cpliakas/git-wrapper.git');
// Create a file in the working copy.
touch('./path/to/working/copy/text.txt');
// Add it, commit it, and push the change.
$git
->add('test.txt')
->commit('Added the test.txt file as per the examples.')
->push();
// Render the output.
print $git->getOutput();
// Execute an arbitrary git command.
// The following is synonymous with `git config -l`
print $wrapper->git('config -l');
All command methods adhere to the following paradigm:, (*3)
$git->command($arg1, $arg2, ..., $options);
Replace command with the Git command being executed, e.g. checkout, push,
etc. The $arg* parameters are a variable number of arguments as they would be
passed to the Git command line tool. $options is an optional array of command
line options in the following format:, (*4)
$options = array(
'verbose' => true, // Passes the "--verbose" flag.
't' => 'my-branch', // Passes the "-t my-branch" option.
);
Installation
To install the required libraries, execute the following commands in the
directory where this library is extracted., (*5)
curl -s https://getcomposer.org/installer | php
php composer.phar install
If curl is not available, replace the first command with the one below:, (*6)
php -r "eval('?>'.file_get_contents('https://getcomposer.org/installer'));"
Please refer to the Composer tool's
installation documentation
for more information., (*7)
Gotchas
There are a few "gotchas" that are out of scope for this library to solve but
might prevent a successful implementation of running Git via PHP. The following
is an incomplete list of challenges that are often encountered when executing
Git from PHP., (*8)
Missing HOME Environment Variable
Sometimes the HOME environment variable is not set in the Git process that is
spawned by PHP. This will cause many Git operations to fail. It is advisable to
set the HOME environment variable to a path outside of the document root that
the web server has write access to. Note that this environment variable is only
set for the process running Git and NOT the PHP process that is spawns it., (*9)
$wrapper->setEnvVar('HOME', '/path/to/a/private/writable/dir');
It is important that the storage is persistent as the ~/.gitconfig file will be
written to this location. See the following "gotcha" for why this is important., (*10)
Missing Identity And Configurations
Many repositories require that a name and email address are specified. This data
is set by running git config [name] [value] on the command line, and the
configurations are usually stored in the ~/.gitconfig file. When executing Git
via PHP, however, the process might have a different home directory than the
user who normally runs git via the command line. Therefore no identity is sent
to the repository, and it will likely throw an error., (*11)
// Set configuration options globally.
$wrapper->git('config --global user.name "User name"');
$wrapper->git('config --global user.email user@example.com');
// Set configuration options per repository.
$git
->config('user.name', 'User name')
->config('user.email', 'user@example.com');
Commits To Repositories With No Changes
Running git commit on a repository with no changes returns no output but exits
with a status of 1. Therefore the library will throw a GitException since it
correctly detected an error. It is advisable to check whether a working copy has
any changes prior to running the commit operation in order to prevent unwanted
exceptions., (*12)
if ($git->hasChanges()) {
$git->commit('Committed the changes.');
}
Permissions Of The GIT_SSH Wrapper Script
On checkout, the bin/git-ssh-wrapper.sh script should be executable. If it is
not, git commands with fail if a non-default private key is specified., (*13)
$> chmod 0755 ./bin/git-ssh-wrapper.sh
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