(PHP 4 >= 4.0.4, PHP 5)
ctype_cntrl — Check for control character(s)
Checks if all of the characters in the provided string, text , are control characters. Control characters are e.g. line feed, tab, escape.
The tested string.
Returns TRUE if every character in text is a control character from the current locale, FALSE otherwise.
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";
}
}
?>
上例将输出：
The string 'string1' consists of all control characters. The string 'string2' does not consist of all control characters.