phpmyadmin/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  * Defines a set of function callbacks that have a pure C version available if
   7  * the "ctype" extension is available, but otherwise have PHP versions to use
   8  * (that are slower).
   9  *
  10  * The SQL Parser code relies heavily on these functions.
  11  *
  12  * @todo a .lib filename should not have code in main(), split or rename file
  13  * @package PhpMyAdmin-String
  14  */
  15 if (! defined('PHPMYADMIN')) {
  16     exit;
  17 }
  18
  19 /**
  20  * Load proper code for handling input.
  21  */
  22 if (@function_exists('mb_strlen')) {
  23     mb_internal_encoding('utf-8');
  24     include './libraries/string_mb.lib.php';
  25 } else {
  26     include './libraries/string_native.lib.php';
  27 }
  28
  29 /**
  30  * Load ctype handler.
  31  */
  32 if (@extension_loaded('ctype')) {
  33     include './libraries/string_type_ctype.lib.php';
  34 } else {
  35     include './libraries/string_type_native.lib.php';
  36 }
  37
  38 /**
  39  * Checks if a given character position in the string is escaped or not
  40  *
  41  * @param string  $string string to check for
  42  * @param integer $pos    the character to check for
  43  * @param integer $start  starting position in the string
  44  *
  45  * @return boolean  whether the character is escaped or not
  46  */
  47 function PMA_STR_charIsEscaped($string, $pos, $start = 0)
  48 {
  49     $pos = max(intval($pos), 0);
  50     $start = max(intval($start), 0);
  51     $len = PMA_strlen($string);
  52     // Base case:
  53     // Check for string length or invalid input or special case of input
  54     // (pos == $start)
  55     if ($pos <= $start || $len <= max($pos, $start)) {
  56         return false;
  57     }
  58
  59     $pos--;
  60     $escaped     = false;
  61     while ($pos >= $start && PMA_substr($string, $pos, 1) == '\\') {
  62         $escaped = !$escaped;
  63         $pos--;
  64     } // end while
  65
  66     return $escaped;
  67 } // end of the "PMA_STR_charIsEscaped()" function
  68
  69
  70 /**
  71  * Checks if a number is in a range
  72  *
  73  * @param integer $num   number to check for
  74  * @param integer $lower lower bound
  75  * @param integer $upper upper bound
  76  *
  77  * @return boolean  whether the number is in the range or not
  78  */
  79 function PMA_STR_numberInRangeInclusive($num, $lower, $upper)
  80 {
  81     return ($num >= $lower && $num <= $upper);
  82 } // end of the "PMA_STR_numberInRangeInclusive()" function
  83
  84 /**
  85  * Checks if a character is an SQL identifier
  86  *
  87  * @param string  $c            character to check for
  88  * @param boolean $dot_is_valid whether the dot character is valid or not
  89  *
  90  * @return boolean  whether the character is an SQL identifier or not
  91  */
  92 function PMA_STR_isSqlIdentifier($c, $dot_is_valid = false)
  93 {
  94     return (PMA_STR_isAlnum($c)
  95         || ($ord_c = ord($c)) && $ord_c >= 192 && $ord_c != 215 && $ord_c != 249
  96         || $c == '_'
  97         || $c == '$'
  98         || ($dot_is_valid != false && $c == '.'));
  99 } // end of the "PMA_STR_isSqlIdentifier()" function
 100
 101 ?>