includes/utils/ExecutableFinder.php

   1 <?php
   2 /**
   3  * Copyright (C) 2017 Kunal Mehta <legoktm@member.fsf.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  */
  20
  21 use MediaWiki\Shell\Shell;
  22
  23 /**
  24  * Utility class to find executables in likely places
  25  *
  26  * @since 1.31
  27  */
  28 class ExecutableFinder {
  29
  30         /**
  31          * Get an array of likely places we can find executables. Check a bunch
  32          * of known Unix-like defaults, as well as the PATH environment variable
  33          * (which should maybe make it work for Windows?)
  34          *
  35          * @return array
  36          */
  37         protected static function getPossibleBinPaths() {
  38                 return array_unique( array_merge(
  39                         [ '/usr/bin', '/bin', '/usr/local/bin', '/opt/csw/bin',
  40                                 '/usr/gnu/bin', '/usr/sfw/bin', '/sw/bin', '/opt/local/bin' ],
  41                         explode( PATH_SEPARATOR, getenv( 'PATH' ) )
  42                 ) );
  43         }
  44
  45         /**
  46          * Search a path for any of the given executable names. Returns the
  47          * executable name if found. Also checks the version string returned
  48          * by each executable.
  49          *
  50          * Used only by environment checks.
  51          *
  52          * @param string $path Path to search
  53          * @param string $name Executable name to look for
  54          * @param array|bool $versionInfo False or array with two members:
  55          *   0 => Parameter to pass to binary for version check (e.g. --version)
  56          *   1 => String to compare the output with
  57          *
  58          * If $versionInfo is not false, only executables with a version
  59          * matching $versionInfo[1] will be returned.
  60          * @return bool|string
  61          */
  62         protected static function findExecutable( $path, $name, $versionInfo = false ) {
  63                 $command = $path . DIRECTORY_SEPARATOR . $name;
  64
  65                 Wikimedia\suppressWarnings();
  66                 $file_exists = is_executable( $command );
  67                 Wikimedia\restoreWarnings();
  68
  69                 if ( $file_exists ) {
  70                         if ( !$versionInfo ) {
  71                                 return $command;
  72                         }
  73
  74                         $output = Shell::command( $command, $versionInfo[0] )
  75                                 ->includeStderr()->execute()->getStdout();
  76                         if ( strstr( $output, $versionInfo[1] ) !== false ) {
  77                                 return $command;
  78                         }
  79                 }
  80
  81                 return false;
  82         }
  83
  84         /**
  85          * Same as locateExecutable(), but checks in getPossibleBinPaths() by default
  86          * @see locateExecutable()
  87          * @param string|string[] $names Array of possible names.
  88          * @param array|bool $versionInfo Default: false or array with two members:
  89          *   0 => Parameter to run for version check, e.g. '--version'
  90          *   1 => String to compare the output with
  91          *
  92          * If $versionInfo is not false, only executables with a version
  93          * matching $versionInfo[1] will be returned.
  94          * @return bool|string
  95          */
  96         public static function findInDefaultPaths( $names, $versionInfo = false ) {
  97                 $paths = self::getPossibleBinPaths();
  98                 foreach ( (array)$names as $name ) {
  99                         foreach ( $paths as $path ) {
 100                                 $exe = self::findExecutable( $path, $name, $versionInfo );
 101                                 if ( $exe !== false ) {
 102                                         return $exe;
 103                                 }
 104                         }
 105                 }
 106
 107                 return false;
 108         }
 109
 110 }