For easier command line using, I've added a new command with symfony/console

bin/minify

@@ -0,0 +1,26 @@
+#!/usr/bin/env php
+<?php
+
+// check if script run in cli environment
+if ('cli' !== php_sapi_name()) {
+    fwrite(STDERR, $argv[1].' must be run in the command line'.PHP_EOL);
+    exit(1);
+}
+
+// command line utility to minify CSS
+if (file_exists(__DIR__.'/../../../autoload.php')) {
+    // if composer install
+    require_once __DIR__.'/../../../autoload.php';
+} else {
+    require __DIR__.'/../vendor/autoload.php';
+}
+
+$minify = new \MatthiasMullie\Minify\Command\MinifyCommand();
+
+array_splice($argv, 1, 0, $minify->getName());
+
+$argInput = new \Symfony\Component\Console\Input\ArgvInput($argv);
+
+$app = new \Symfony\Component\Console\Application();
+$app->add($minify);
+$app->run($argInput);

composer.json

@@ -16,7 +16,8 @@
     "require": {
         "php": ">=5.3.0",
         "ext-pcre": "*",
-        "matthiasmullie/path-converter": "~1.0"
+        "matthiasmullie/path-converter": "~1.0",
+        "symfony/console": ">=2.0"
     },
     "require-dev": {
         "matthiasmullie/scrapbook": "~1.0",
@@ -29,6 +30,7 @@
     },
     "bin": [
         "bin/minifycss",
-        "bin/minifyjs"
+        "bin/minifyjs",
+        "bin/minify"
     ]
 }

src/Command/MinifyCommand.php

@@ -0,0 +1,118 @@
+<?php
+
+namespace MatthiasMullie\Minify\Command;
+
+use MatthiasMullie\Minify\CSS;
+use MatthiasMullie\Minify\JS;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class MinifyCommand extends Command
+{
+    protected function configure()
+    {
+        $this->setName('minify')
+            ->setDescription('Minify js or css')
+            ->addArgument(
+                'from',
+                InputArgument::REQUIRED | InputArgument::IS_ARRAY,
+                'From which files you wanna to minify'
+            )
+            ->addOption(
+                'type',
+                't',
+                InputOption::VALUE_OPTIONAL,
+                'Which type of file you wanna minify? js or css (Default is auto detected according to the extension name.)'
+            )
+            ->addOption(
+                'output',
+                'o',
+                InputOption::VALUE_OPTIONAL,
+                'The output file (Default is STDOUT)'
+            )
+            ->addOption(
+                'append',
+                'a',
+                InputOption::VALUE_OPTIONAL,
+                'Append to the file (Default is overwrite)'
+            );
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output)
+    {
+        $from = $input->getArgument('from');
+        $type = $input->getOption('type');
+        $outputFile = $input->getOption('output');
+        $appendFile = $input->getOption('append');
+
+        if (!is_array($from)) {
+            $from = (array) $from;
+        }
+
+        if (empty($type)) {
+            $autoDetectedType = self::getFileExt($from[0]);
+            foreach ($from as $fromFile) {
+                $fileExt = self::getFileExt($fromFile);
+                if (strcasecmp($fileExt, $autoDetectedType) !== 0) {
+                    $output->writeln('<error>Error: type of input files is not all the same!</error>');
+
+                    return 1;
+                }
+            }
+
+            $type = $autoDetectedType;
+        }
+
+        if (empty($type)) {
+            $output->writeln('<error>Error: cannot find the type of input file!</error>');
+
+            return 1;
+        }
+
+        switch (strtolower($type)) {
+            case 'css':
+                $minifier = new CSS();
+                break;
+            case 'js':
+                $minifier = new JS();
+                break;
+            default:
+                $output->writeln("<error>Error: Unsupported type: $type</error>");
+
+                return 3;
+        }
+
+        foreach ($from as $fromFile) {
+            if (!file_exists($fromFile)) {
+                $output->writeln("<error>Error: File '{$fromFile}' not found!</error>");
+
+                return 2;
+            }
+            $minifier->add($fromFile);
+        }
+
+        $result = $minifier->minify();
+
+        if (empty($outputFile) && empty($appendFile)) {
+            $output->writeln($result, OutputInterface::OUTPUT_RAW);
+        } else {
+            if (!empty($outputFile)) {
+                file_put_contents($outputFile, $result);
+            }
+
+            if (!empty($appendFile)) {
+                file_put_contents($appendFile, $result, FILE_APPEND);
+            }
+        }
+
+        return 0;
+    }
+
+    public static function getFileExt($fileName)
+    {
+        return ltrim(strrchr($fileName, '.'), '.');
+    }
+}