Recipe 24.12. Program: Web Server Directory Listing


The web-ls.php program shown in Example 24-28 (later in this recipe) provides a view of the files inside your web server's document root, formatted like the output of the Unix command ls. Filenames are linked so that you can download each file, and directory names are linked so that you can browse in each directory, as shown in Figure 24-1.

Web listing


Most lines in Example 24-28 are devoted to building an easy-to-read representation of the file's permissions, but the guts of the program are in the foreach loop at the end. The DirectoryIterator yields an element for each entry in the directory. Then, various methods on the element's object provide information about that file, and printf( ) prints out the formatted information about that file.

The mode_string( ) functions and the constants it uses turn the octal representation of a file's mode (e.g., 35316) into an easier-to-read string (e.g., -rwsrw-r--).

web-ls.php

<?php /* Bit masks for determining file permissions and type. The names and values  * listed below are POSIX-compliant; individual systems may have their own  * extensions.  */ define('S_IFMT',0170000);   // mask for all types define('S_IFSOCK',0140000); // type: socket define('S_IFLNK',0120000);  // type: symbolic link define('S_IFREG',0100000);  // type: regular file define('S_IFBLK',0060000);  // type: block device define('S_IFDIR',0040000);  // type: directory define('S_IFCHR',0020000);  // type: character device define('S_IFIFO',0010000);  // type: fifo define('S_ISUID',0004000);  // set-uid bit define('S_ISGID',0002000);  // set-gid bit define('S_ISVTX',0001000);  // sticky bit define('S_IRWXU',00700);    // mask for owner permissions define('S_IRUSR',00400);    // owner: read permission define('S_IWUSR',00200);    // owner: write permission define('S_IXUSR',00100);    // owner: execute permission define('S_IRWXG',00070);    // mask for group permissions define('S_IRGRP',00040);    // group: read permission define('S_IWGRP',00020);    // group: write permission define('S_IXGRP',00010);    // group: execute permission define('S_IRWXO',00007);    // mask for others permissions define('S_IROTH',00004);    // others: read permission define('S_IWOTH',00002);    // others: write permission define('S_IXOTH',00001);    // others: execute permission /* mode_string() is a helper function that takes an octal mode and returns  * a 10-character string representing the file type and permissions that  * correspond to the octal mode. This is a PHP version of the mode_string()  * function in the GNU fileutils package.  */ $mode_type_map = array(S_IFBLK => 'b', S_IFCHR => 'c',                        S_IFDIR => 'd', S_IFREG => '-',                        S_IFIFO => 'p', S_IFLNK => 'l',                        S_IFSOCK => 's'); function mode_string($mode) {     global $mode_type_map;     $s = '';     $mode_type = $mode & S_IFMT;     // Add the type character     $s .= isset($mode_type_map[$mode_type]) ?           $mode_type_map[$mode_type] : '?';   // set user permissions   $s .= $mode & S_IRUSR ? 'r' : '-';   $s .= $mode & S_IWUSR ? 'w' : '-';   $s .= $mode & S_IXUSR ? 'x' : '-';   // set group permissions   $s .= $mode & S_IRGRP ? 'r' : '-';   $s .= $mode & S_IWGRP ? 'w' : '-';   $s .= $mode & S_IXGRP ? 'x' : '-';   // set other permissions   $s .= $mode & S_IROTH ? 'r' : '-';   $s .= $mode & S_IWOTH ? 'w' : '-';   $s .= $mode & S_IXOTH ? 'x' : '-';   // adjust execute letters for set-uid, set-gid, and sticky   if ($mode & S_ISUID) {       // 'S' for set-uid but not executable by owner       $s[3] = ($s[3] == 'x') ? 's' : 'S';   }   if ($mode & S_ISGID) {       // 'S' for set-gid but not executable by group       $s[6] = ($s[6] == 'x') ? 's' : 'S';   }   if ($mode & S_ISVTX) {       // 'T' for sticky but not executable by others       $s[9] = ($s[9] == 'x') ? 't' : 'T';   }   return $s; } // start at the document root if not specified $dir = isset($_GET['dir']) ? $_GET['dir'] : ''; // locate $dir in the filesystem $real_dir = realpath($_SERVER['DOCUMENT_ROOT'].$dir); // Passing document root through realpath resolves any // forward-slash vs. backslash issues $real_docroot = realpath($_SERVER['DOCUMENT_ROOT']); // make sure $real_dir is inside document root if (! (($real_dir == $real_docroot) ||        ((strlen($real_dir) > strlen($real_docroot)) &&         (strncasecmp($real_dir,$real_docroot.DIRECTORY_SEPARATOR,         strlen($real_docroot.DIRECTORY_SEPARATOR)) == 0)))) {     die("$dir is not inside the document root"); } // canonicalize $dir by removing the document root from its beginning $dir = substr($real_dir,strlen($real_docroot)+1); // are we opening a directory? if (! is_dir($real_dir)) {     die("$real_dir is not a directory"); } print '<pre><table>'; // read each entry in the directory foreach (new DirectoryIterator($real_dir) as $file) {     // translate uid into user name     if (function_exists('posix_getpwuid')) {         $user_info = posix_getpwuid($file->getOwner());     } else {         $user_info = $file->getOwner();     }     // translate gid into group name     if (function_exists('posix_getgrid')) {         $group_info = $file->getGroup();     } else {         $group_info = $file->getGroup();     }     // format the date for readability     $date = date('M d H:i',$file->getMTime());     // translate the octal mode into a readable string     $mode = mode_string($file->getPerms());     $mode_type = substr($mode,0,1);     if (($mode_type == 'c') || ($mode_type == 'b')) {         /* if it's a block or character device, print out the major and          * minor device type instead of the file size */         $statInfo = lstat($file->getPathname());         $major = ($statInfo['rdev'] >> 8) & 0xff;         $minor = $statInfo['rdev'] & 0xff;         $size = sprintf('%3u, %3u',$major,$minor);     } else {         $size = $file->getSize();     }     // format the <a href=""> around the filename     // no link for the current directory     if ('.' == $file->getFilename()) {         $href = $file->getFilename();     } else {         // don't include the ".." in the parent directory link         if ('..' == $file->getFilename()) {             $href = urlencode(dirname($dir));         } else {             $href = urlencode($dir) . '/' . urlencode($file);         }         /* everything but "/" should be urlencoded */         $href = str_replace('%2F','/',$href);         // browse other directories with web-ls         if ($file->isDir()) {             $href = sprintf('<a href="%s?dir=/%s">%s</a>',                             $_SERVER['PHP_SELF'],$href,$file);         } else {             // link to files to download them             $href= sprintf('<a href="%s">%s</a>',$href,$file);         }         // if it's a link, show the link target, too         if ('l' == $mode_type) {             $href .= ' -&gt; ' . readlink($file->getPathname());         }     }     // print out the appropriate info for this file     printf('<tr><td>%s</td><td align="right">%s</td>             <td align="right">%s</td><td align="right">%s</td>             <td align="right">%s</td><td>%s</td></tr>',            $mode,                // formatted mode string            $user_info['name'],   // owner's user name            $group_info['name'],  // group name            $size,                // file size (or device numbers)            $date,                // last modified date and time            $href);               // link to browse or download } print '</table></pre>'; ?>




PHP Cookbook, 2nd Edition
PHP Cookbook: Solutions and Examples for PHP Programmers
ISBN: 0596101015
EAN: 2147483647
Year: 2006
Pages: 445

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