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PHP Manual for

ctype_cntrl

(PHP 4 >= 4.0.4)

ctype_cntrl -- Check for control character(s)

Description

bool ctype_cntrl ( string text)

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.