Checks if all of the characters in the provided string,
text, are control characters.
Control characters are e.g. line feed, tab, esc.
Parameters
text
The tested string.
Return Values
Returns TRUE if every character in text is
a letter from the current locale, FALSE otherwise.
Examples
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"; } } ?>
The above example will output:
The string 'string1' consists of all control characters.
The string 'string2' does not consists of all control characters.
