libraries/string.lib.php

   1 <?php
   2 /* vim: set expandtab sw=4 ts=4 sts=4: */
   3 /**
   4  * Specialized String Functions for phpMyAdmin
   5  *
   6  * Copyright 2002 Robin Johnson <robbat2@users.sourceforge.net>
   7  * http://www.orbis-terrarum.net/?l=people.robbat2
   8  *
   9  * Defines a set of function callbacks that have a pure C version available if
  10  * the "ctype" extension is available, but otherwise have PHP versions to use
  11  * (that are slower).
  12  *
  13  * The SQL Parser code relies heavily on these functions.
  14  *
  15  * @version $Id$
  16  * @uses    extension_loaded()
  17  * @uses    substr()
  18  * @uses    function_exists()
  19  * @uses    mb_internal_encoding()
  20  * @uses    defined()
  21  * @todo a .lib filename should not have code in main(), split or rename file
  22  * @package phpMyAdmin
  23  */
  24 if (! defined('PHPMYADMIN')) {
  25     exit;
  26 }
  27
  28 $GLOBALS['PMA_allow_mbstr'] = @function_exists('mb_strlen');
  29 $GLOBALS['PMA_allow_ctype'] = @extension_loaded('ctype');
  30
  31 if ($GLOBALS['PMA_allow_mbstr']) {
  32     mb_internal_encoding($GLOBALS['charset']);
  33 }
  34
  35 /**
  36  * Load proper code for handling input.
  37  */
  38 if (defined('PMA_MULTIBYTE_ENCODING') || $GLOBALS['PMA_allow_mbstr']) {
  39     $GLOBALS['PMA_strpos']      = 'mb_strpos';
  40     $GLOBALS['PMA_substr']      = 'mb_substr';
  41     require './libraries/string_mb.lib.php';
  42 } else {
  43     $GLOBALS['PMA_strpos']      = 'strpos';
  44     $GLOBALS['PMA_substr']      = 'substr';
  45     require './libraries/string_native.lib.php';
  46 }
  47
  48 /**
  49  * Load ctype handler.
  50  */
  51 if ($GLOBALS['PMA_allow_ctype']) {
  52     $GLOBALS['PMA_STR_isAlnum'] = 'ctype_alnum';
  53     $GLOBALS['PMA_STR_isDigit'] = 'ctype_digit';
  54     $GLOBALS['PMA_STR_isSpace'] = 'ctype_space';
  55     require './libraries/string_type_ctype.lib.php';
  56 } else {
  57     $GLOBALS['PMA_STR_isAlnum'] = 'PMA_STR_isAlnum';
  58     $GLOBALS['PMA_STR_isDigit'] = 'PMA_STR_isDigit';
  59     $GLOBALS['PMA_STR_isSpace'] = 'PMA_STR_isSpace';
  60     require './libraries/string_type_native.lib.php';
  61 }
  62
  63 /**
  64  * Checks if a given character position in the string is escaped or not
  65  *
  66  * @uses    PMA_strlen()
  67  * @uses    PMA_substr()
  68  * @uses    max()
  69  * @uses    intval()
  70  * @param   string   string to check for
  71  * @param   integer  the character to check for
  72  * @param   integer  starting position in the string
  73  * @return  boolean  whether the character is escaped or not
  74  */
  75 function PMA_STR_charIsEscaped($string, $pos, $start = 0)
  76 {
  77     $pos = max(intval($pos), 0);
  78     $start = max(intval($start), 0);
  79     $len = PMA_strlen($string);
  80     // Base case:
  81     // Check for string length or invalid input or special case of input
  82     // (pos == $start)
  83     if ($pos <= $start || $len <= max($pos, $start)) {
  84         return false;
  85     }
  86
  87     $pos--;
  88     $escaped     = false;
  89     while ($pos >= $start && PMA_substr($string, $pos, 1) == '\\') {
  90         $escaped = !$escaped;
  91         $pos--;
  92     } // end while
  93
  94     return $escaped;
  95 } // end of the "PMA_STR_charIsEscaped()" function
  96
  97
  98 /**
  99  * Checks if a number is in a range
 100  *
 101  * @param   integer  number to check for
 102  * @param   integer  lower bound
 103  * @param   integer  upper bound
 104  * @return  boolean  whether the number is in the range or not
 105  */
 106 function PMA_STR_numberInRangeInclusive($num, $lower, $upper)
 107 {
 108     return ($num >= $lower && $num <= $upper);
 109 } // end of the "PMA_STR_numberInRangeInclusive()" function
 110
 111 /**
 112  * Checks if a character is an SQL identifier
 113  *
 114  * @uses    PMA_STR_isAlnum()
 115  * @param   string   character to check for
 116  * @param   boolean  whether the dot character is valid or not
 117  * @return  boolean  whether the character is an SQL identifier or not
 118  */
 119 function PMA_STR_isSqlIdentifier($c, $dot_is_valid = false)
 120 {
 121     return ($GLOBALS['PMA_STR_isAlnum']($c)
 122         || ($ord_c = ord($c)) && $ord_c >= 192 && $ord_c != 215 && $ord_c != 249
 123         || $c == '_'
 124         || $c == '$'
 125         || ($dot_is_valid != false && $c == '.'));
 126 } // end of the "PMA_STR_isSqlIdentifier()" function
 127
 128
 129 /**
 130  * Binary search of a value in a sorted array
 131  *
 132  * $arr MUST be sorted, due to binary search
 133  *
 134  * @param   string   string to search for
 135  * @param   array    sorted array to search into
 136  * @param   integer  size of sorted array to search into
 137  *
 138  * @return  boolean  whether the string has been found or not
 139  */
 140 function PMA_STR_binarySearchInArr($str, $arr, $arrsize)
 141 {
 142     $top    = $arrsize - 1;
 143     $bottom = 0;
 144     $found  = false;
 145
 146     while ($top >= $bottom && $found == false) {
 147         $mid        = intval(($top + $bottom) / 2);
 148         $res        = strcmp($str, $arr[$mid]);
 149         if ($res == 0) {
 150             $found  = true;
 151         } elseif ($res < 0) {
 152             $top    = $mid - 1;
 153         } else {
 154             $bottom = $mid + 1;
 155         }
 156     } // end while
 157
 158     return $found;
 159 } // end of the "PMA_STR_binarySearchInArr()" function
 160
 161 ?>