includes/shell/Shell.php

   1 <?php
   2 /**
   3  * Class used for executing shell commands
   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  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 namespace MediaWiki\Shell;
  24
  25 use MediaWiki\MediaWikiServices;
  26
  27 /**
  28  * Executes shell commands
  29  *
  30  * @since 1.30
  31  *
  32  * Use call chaining with this class for expressiveness:
  33  *  $result = Shell::command( 'some command' )
  34  *       ->environment( [ 'ENVIRONMENT_VARIABLE' => 'VALUE' ] )
  35  *       ->limits( [ 'time' => 300 ] )
  36  *       ->execute();
  37  *
  38  *  ... = $result->getExitCode();
  39  *  ... = $result->getStdout();
  40  *  ... = $result->getStderr();
  41  */
  42 class Shell {
  43
  44         /**
  45          * Returns a new instance of Command class
  46          *
  47          * @param string|string[] $command String or array of strings representing the command to
  48          * be executed, each value will be escaped.
  49          *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
  50          * @return Command
  51          */
  52         public static function command( $command ) {
  53                 $args = func_get_args();
  54                 if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
  55                         // If only one argument has been passed, and that argument is an array,
  56                         // treat it as a list of arguments
  57                         $args = reset( $args );
  58                 }
  59                 $command = MediaWikiServices::getInstance()
  60                         ->getShellCommandFactory()
  61                         ->create();
  62
  63                 return $command->params( $args );
  64         }
  65
  66         /**
  67          * Check if this class is effectively disabled via php.ini config
  68          *
  69          * @return bool
  70          */
  71         public static function isDisabled() {
  72                 static $disabled = null;
  73
  74                 if ( is_null( $disabled ) ) {
  75                         if ( !function_exists( 'proc_open' ) ) {
  76                                 wfDebug( "proc_open() is disabled\n" );
  77                                 $disabled = true;
  78                         } else {
  79                                 $disabled = false;
  80                         }
  81                 }
  82
  83                 return $disabled;
  84         }
  85
  86         /**
  87          * Version of escapeshellarg() that works better on Windows.
  88          *
  89          * Originally, this fixed the incorrect use of single quotes on Windows
  90          * (https://bugs.php.net/bug.php?id=26285) and the locale problems on Linux in
  91          * PHP 5.2.6+ (bug backported to earlier distro releases of PHP).
  92          *
  93          * @param string $args,... strings to escape and glue together, or a single array of
  94          *     strings parameter
  95          * @return string
  96          */
  97         public static function escape( /* ... */ ) {
  98                 $args = func_get_args();
  99                 if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
 100                         // If only one argument has been passed, and that argument is an array,
 101                         // treat it as a list of arguments
 102                         $args = reset( $args );
 103                 }
 104
 105                 $first = true;
 106                 $retVal = '';
 107                 foreach ( $args as $arg ) {
 108                         if ( !$first ) {
 109                                 $retVal .= ' ';
 110                         } else {
 111                                 $first = false;
 112                         }
 113
 114                         if ( wfIsWindows() ) {
 115                                 // Escaping for an MSVC-style command line parser and CMD.EXE
 116                                 // Refs:
 117                                 //  * https://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
 118                                 //  * https://technet.microsoft.com/en-us/library/cc723564.aspx
 119                                 //  * T15518
 120                                 //  * CR r63214
 121                                 // Double the backslashes before any double quotes. Escape the double quotes.
 122                                 $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
 123                                 $arg = '';
 124                                 $iteration = 0;
 125                                 foreach ( $tokens as $token ) {
 126                                         if ( $iteration % 2 == 1 ) {
 127                                                 // Delimiter, a double quote preceded by zero or more slashes
 128                                                 $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
 129                                         } elseif ( $iteration % 4 == 2 ) {
 130                                                 // ^ in $token will be outside quotes, need to be escaped
 131                                                 $arg .= str_replace( '^', '^^', $token );
 132                                         } else { // $iteration % 4 == 0
 133                                                 // ^ in $token will appear inside double quotes, so leave as is
 134                                                 $arg .= $token;
 135                                         }
 136                                         $iteration++;
 137                                 }
 138                                 // Double the backslashes before the end of the string, because
 139                                 // we will soon add a quote
 140                                 $m = [];
 141                                 if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
 142                                         $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
 143                                 }
 144
 145                                 // Add surrounding quotes
 146                                 $retVal .= '"' . $arg . '"';
 147                         } else {
 148                                 $retVal .= escapeshellarg( $arg );
 149                         }
 150                 }
 151                 return $retVal;
 152         }
 153 }