This is available for PHP 3, PHP 4, & PHP 5.

strtoupper -- Make a string uppercase

Description
string strtoupper ( string )

Returns string with all alphabetic characters converted to uppercase.

Note that 'alphabetic' is determined by the current locale. For instance, in the default "C" locale characters such as umlaut-a (รค) will not be converted.

Example 1. strtoupper() example

PLAIN TEXT
CODE:
  1. <?php
  2. $string = "This is a test of the Emergency Broadcasting system...";
  3. $string = strtoupper($string);
  4. echo $string;  // echos - THIS IS A TEST OF THE EMERGENCY BROADCASTING SYSTEM...

Note: This function is binary-safe.