ProcessUtils.php

The ProcessUtils.php file in the Illuminate\Support namespace is a bunch of utility methods, originally copied from Symfony 3. It provides a class called ProcessUtils which contains two methods: escapeArgument and isSurroundedBy.

Methods

escapeArgument

This method takes a string argument and escapes it for use as a shell argument. It addresses two PHP bugs related to escapeshellarg not working correctly on Windows and removing % from the given string. The method replaces invalid characters and wraps the argument in quotes if necessary.

isSurroundedBy

This method takes two string arguments and checks if the first string is surrounded by the second character. It returns true if the string is surrounded, and false otherwise.

<?php

namespace Illuminate\Support;

/**
 * ProcessUtils is a bunch of utility methods.
 *
 * This class was originally copied from Symfony 3.
 */
class ProcessUtils
{
    /**
     * Escapes a string to be used as a shell argument.
     *
     * @param  string  $argument
     * @return string
     */
    public static function escapeArgument($argument)
    {
        // Fix for PHP bug #43784 escapeshellarg removes % from given string
        // Fix for PHP bug #49446 escapeshellarg doesn't work on Windows
        // @see https://bugs.php.net/bug.php?id=43784
        // @see https://bugs.php.net/bug.php?id=49446
        if ('\\' === DIRECTORY_SEPARATOR) {
            if ($argument === '') {
                return '""';
            }

            $escapedArgument = '';
            $quote = false;

            foreach (preg_split('/(")/', $argument, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE) as $part) {
                if ($part === '"') {
                    $escapedArgument .= '\\"';
                } elseif (self::isSurroundedBy($part, '%')) {
                    // Avoid environment variable expansion
                    $escapedArgument .= '^%"'.substr($part, 1, -1).'"^%';
                } else {
                    // escape trailing backslash
                    if (str_ends_with($part, '\\')) {
                        $part .= '\\';
                    }
                    $quote = true;
                    $escapedArgument .= $part;
                }
            }

            if ($quote) {
                $escapedArgument = '"'.$escapedArgument.'"';
            }

            return $escapedArgument;
        }

        return "'".str_replace("'", "'\\''", $argument)."'";
    }

    /**
     * Is the given string surrounded by the given character?
     *
     * @param  string  $arg
     * @param  string  $char
     * @return bool
     */
    protected static function isSurroundedBy($arg, $char)
    {
        return strlen($arg) > 2 && $char === $arg[0] && $char === $arg[strlen($arg) - 1];
    }
}