Increase the version of the latest tag on the current git branch and push the tag.

tagger.php

<?php
/***********************************************************
Hacky script to increase the version of the latest tag
on the current branch and push the tag. Assumes a simple
SemVer tag of the format vx.x.x
************************************************************/

$usage = 'Usage: php tag.php [major|minor|patch]' . PHP_EOL;

if (count($argv) != 2) {
	die($usage);
}

$latestTag = exec('git describe --tags --abbrev=0');

$parts = explode('.', $latestTag);

$valid = substr($parts[0],0,1) == 'v' && count($parts) == 3 && is_numeric(substr($parts[0], 1)) && is_numeric($parts[1]) && is_numeric($parts[2]);

if (!$valid) {
	die('Expecting latest tag to be of format: vx.x.x' . PHP_EOL);
}

switch ($argv[1]) {
	case 'major' :
	    $part0 = (substr($parts[0], 1)+1);
	    $newTag = 'v' . $part0 . '.0.0';
	    break;
	case 'minor' :
	    $newTag = $parts[0] . '.' . ($parts[1]+1) . '.0';
	    break;
	case 'patch' :
	    $newTag = $parts[0] . '.' . $parts[1] . '.' . ($parts[2]+1);
            break;
	case 'default' :
	    die($usage);
}

echo 'Creating new tag ' . $newTag . PHP_EOL;
exec('git tag ' . $newTag);
echo 'Pushing new tag...' . PHP_EOL;
exec('git push --tags');