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