ctype_cntrl

Description

Returns TRUE if every character in text has a special control function, FALSE otherwise. Control characters are e.g. line feed, tab, esc.

Example 1. A ctype_cntrl() example <?php $strings = array('string1' => "\n\r\t", 'string2' => 'arf12'); foreach ($strings as $name => $testcase) {     if (ctype_cntrl($testcase)) {         echo "The string '$name' consists of all control characters.\n";     } else {         echo "The string '$name' does not consist of all control characters.\n";     } } ?> This example will output : The string 'string1' consists of all control characters. The string 'string2' does not consists of all control characters.