(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";
}
}
?>
以上例程会输出：
The string 'string1' consists of all control characters. The string 'string2' does not consist of all control characters.