ctype_print

    (PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)

    ctype_print — Check for printable character(s)

    Description

    ctype_print(mixed $text): bool

    Checks if all of the characters in the provided string, text, are printable.

    Parameters

    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.

    Warning

    As of PHP 8.1.0, passing a non-string argument is deprecated. In the future, the argument will be interpreted as a string instead of an ASCII codepoint. Depending on the intended behavior, the argument should either be cast to string or an explicit call to chr() should be made.

    Return Values

    Returns true if every character in text will actually create output (including blanks). Returns false if text contains control characters or characters that do not have any output or control function at all. When called with an empty string the result will always be false.

    Examples

    Example #1 A ctype_print() example

    <?php
    $strings     = array('string1' => "asdf\n\r\t", 'string2' => 'arf12', 'string3' => 'LKA#@%.54');
    foreach (    $strings as $name => $testcase) {
    if (    ctype_print($testcase)) {
    echo     "The string '$name' consists of all printable characters.\n";
    } else {
    echo     "The string '$name' does not consist of all printable characters.\n";
    }
    }
    ?>

    The above example will output:

    The string 'string1' does not consist of all printable characters.
The string 'string2' consists of all printable characters.
The string 'string3' consists of all printable characters.

    See Also

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    User Contributed Notes 4 notes

    up
    4
    ClayDragon
    5 years ago
    As mentioned above, only ASCII characters from 32 to 126 are considered printable, all others, including UTF-8 encoded characters are always considered unprintable, no matter what your locale settings are. Therefore, e.g. German "ä", the Euro sign "€" or the British pound symbol "£" will never be printable. If you need to check any characters for "printability" beyond the standard ASCII range, use a regular expression or write a specific function yourself.

    See also this discussion: https://grokbase.com/t/php/php-i18n/102tkqe6rk/ctype-print-returns-false-for-british-pound-symbol-and-non-ascii-symbols
    up
    3
    Anonymous
    12 years ago
    Only ascii 32 thru 126 (inclusive) are considered printable. Tab (ascii 7), carriage return (ascii 13), linefeed (ascii 10) etc may produce output but are not considered printable.
    up
    2
    harry at upmind dot com
    2 years ago
    You can use this function to detect if a string is "binary".

    <?php
    /**
    * Determine whether the given value is a binary string by checking to see if it contains only printable characters.
    *
    * @param string $value
    *
    * @return bool
    */
    function isBinary($value): bool
    {
    // remove "unprintable" whitespace characters (tabs, newlines etc)
    $string = preg_replace('/\s/', '', (string)$value);

    return !empty(    $string) && !ctype_print($string);
    }
    ?>
    up
    0
    Kalahiri
    1 year ago
    To check whether a string consists only of ASCII characters, use mb_detect_encoding( $string, 'ASCII', true );
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