1 files changed, 115 insertions, 0 deletions
diff --git a/www/wiki/includes/utils/ExecutableFinder.php b/www/wiki/includes/utils/ExecutableFinder.php
new file mode 100644
index 00000000..78b3f8e2
--- /dev/null
+++ b/www/wiki/includes/utils/ExecutableFinder.php
@@ -0,0 +1,115 @@
+<?php
+/**
+ * Copyright (C) 2017 Kunal Mehta <legoktm@member.fsf.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+use MediaWiki\Shell\Shell;
+
+/**
+ * Utility class to find executables in likely places
+ *
+ * @since 1.31
+ */
+class ExecutableFinder {
+
+	/**
+	 * Get an array of likely places we can find executables. Check a bunch
+	 * of known Unix-like defaults, as well as the PATH environment variable
+	 * (which should maybe make it work for Windows?)
+	 *
+	 * @return array
+	 */
+	protected static function getPossibleBinPaths() {
+		return array_unique( array_merge(
+			[ '/usr/bin', '/bin', '/usr/local/bin', '/opt/csw/bin',
+				'/usr/gnu/bin', '/usr/sfw/bin', '/sw/bin', '/opt/local/bin' ],
+			explode( PATH_SEPARATOR, getenv( 'PATH' ) )
+		) );
+	}
+
+	/**
+	 * Search a path for any of the given executable names. Returns the
+	 * executable name if found. Also checks the version string returned
+	 * by each executable.
+	 *
+	 * Used only by environment checks.
+	 *
+	 * @param string $path Path to search
+	 * @param string $name Executable name to look for
+	 * @param array|bool $versionInfo False or array with two members:
+	 *   0 => Parameter to pass to binary for version check (e.g. --version)
+	 *   1 => String to compare the output with
+	 *
+	 * If $versionInfo is not false, only executables with a version
+	 * matching $versionInfo[1] will be returned.
+	 * @return bool|string
+	 */
+	protected static function findExecutable( $path, $name, $versionInfo = false ) {
+		$command = $path . DIRECTORY_SEPARATOR . $name;
+
+		Wikimedia\suppressWarnings();
+		$file_exists = is_executable( $command );
+		Wikimedia\restoreWarnings();
+
+		if ( $file_exists ) {
+			if ( !$versionInfo ) {
+				return $command;
+			}
+
+			$output = Shell::command( $command, $versionInfo[0] )
+				->includeStderr()->execute()->getStdout();
+			if ( strstr( $output, $versionInfo[1] ) !== false ) {
+				return $command;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Same as locateExecutable(), but checks in getPossibleBinPaths() by default
+	 * @see locateExecutable()
+	 * @param string|string[] $names Array of possible names.
+	 * @param array|bool $versionInfo Default: false or array with two members:
+	 *   0 => Parameter to run for version check, e.g. '--version'
+	 *   1 => String to compare the output with
+	 *
+	 * If $versionInfo is not false, only executables with a version
+	 * matching $versionInfo[1] will be returned.
+	 * @return bool|string
+	 */
+	public static function findInDefaultPaths( $names, $versionInfo = false ) {
+		if ( Shell::isDisabled() ) {
+			// If we can't shell out, there's no point looking for executables
+			return false;
+		}
+
+		$paths = self::getPossibleBinPaths();
+		foreach ( (array)$names as $name ) {
+			foreach ( $paths as $path ) {
+				$exe = self::findExecutable( $path, $name, $versionInfo );
+				if ( $exe !== false ) {
+					return $exe;
+				}
+			}
+		}
+
+		return false;
+	}
+
+}