array ( 0 => 'index.php', 1 => 'PHP Manual', ), 'head' => array ( 0 => 'UTF-8', 1 => 'en', ), 'this' => array ( 0 => 'function.ctype-cntrl.php', 1 => 'ctype_cntrl', ), 'up' => array ( 0 => 'ref.ctype.php', 1 => 'Ctype Functions', ), 'prev' => array ( 0 => 'function.ctype-alpha.php', 1 => 'ctype_alpha', ), 'next' => array ( 0 => 'function.ctype-digit.php', 1 => 'ctype_digit', ), 'alternatives' => array ( ), 'source' => array ( 'lang' => 'en', 'path' => 'reference/ctype/functions/ctype-cntrl.xml', ), ); $setup["toc"] = $TOC; $setup["toc_deprecated"] = $TOC_DEPRECATED; $setup["parents"] = $PARENTS; manual_setup($setup); ?>
(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)
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.
text
The tested string.
Note:
If an int between -128 and 255 inclusive is provided, it is interpreted as the ASCII value of a single character (negative values have 256 added in order to allow characters in the Extended ASCII range). Any other integer is interpreted as a string containing the decimal digits of the integer.
Returns true
if every character in text
is
a control character from the current locale, false
otherwise.
When called with an empty string the result will always be false
.
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 consist of all control characters.