silverstripe-textextraction/code/extractors/TikaTextExtractor.php

<?php

/**
 * Enables text extraction of file content via the Tika CLI
 * 
 * {@link http://tika.apache.org/1.7/gettingstarted.html}
 */
class TikaTextExtractor extends FileTextExtractor
{
    /**
     * Text extraction mode. Defaults to -t (plain text)
     *
     * @var string
     * @config
     */
    private static $output_mode = '-t';

    /**
     * Get the version of tika installed, or 0 if not installed
     *
     * @return float version of tika
     */
    public function getVersion()
    {
        $code = $this->runShell('tika --version', $stdout);

        // Parse output
        if (!$code && preg_match('/Apache Tika (?<version>[\.\d]+)/', $stdout, $matches)) {
            return $matches['version'];
        }

        return 0;
    }

    /**
     * Runs an arbitrary and safely escaped shell command
     *
     * @param string $command Full command including arguments
     * @param string &$stdout Standand output
     * @param string &$stderr Standard error
     * @param string $input Content to pass via standard input
     * @return int Exit code. 0 is success
     */
    protected function runShell($command, &$stdout = '', &$stderr = '', $input = '')
    {
        $descriptorSpecs = array(
            0 => array("pipe", "r"),
            1 => array("pipe", "w"),
            2 => array("pipe", "w")
        );
        // Invoke command
        $pipes = array();
        $proc = proc_open($command, $descriptorSpecs, $pipes);
        if (!is_resource($proc)) {
            return 255;
        }

        // Send content as input
        fwrite($pipes[0], $input);
        fclose($pipes[0]);

        // Get output
        $stdout = stream_get_contents($pipes[1]);
        fclose($pipes[1]);
        $stderr = stream_get_contents($pipes[2]);
        fclose($pipes[2]);

        // Get result
        return proc_close($proc);
    }
    
    public function getContent($path)
    {
        $mode = $this->config()->output_mode;
        $command = sprintf('tika %s %s', $mode, escapeshellarg($path));
        $code = $this->runShell($command, $output);
        if ($code == 0) {
            return $output;
        }
    }

    public function isAvailable()
    {
        return $this->getVersion() > 0;
    }

    public function supportsExtension($extension)
    {
        // Determine support via mime type only
        return false;
    }

    public function supportsMime($mime)
    {
        // Get list of supported mime types
        $code = $this->runShell('tika --list-supported-types', $supportedTypes, $error);
        if ($code) {
            return false;
        } // Error case

        // Check if the mime type is inside the result
        $pattern = sprintf('/\b(%s)\b/', preg_quote($mime, '/'));
        return (bool)preg_match($pattern, $supportedTypes);
    }
}