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    strcspn

    (PHP 4, PHP 5, PHP 7, PHP 8)

    strcspn — Encontra o tamanho do segmento inicial que não contenha a máscara

    Descrição

    strcspn(
        string $str1,
        string $str2,
        int $start = ?,
        int $length = ?
    ): int

    Retorna o tamanho do segmento inicial de str1 que não contém nenhum dos caracteres em str2.

    Parâmetros

    str1

    A primeira string.

    str2

    A segunda string.

    start

    A posição inicial da string.

    length

    O tamanho da string.

    Valor Retornado

    Retorna o tamanho do segmento como um inteiro.

    Notas

    Nota: Esta função é compatível com dados binários.

    Veja Também

    • strspn() - Encontra o comprimento do segmento inicial combinando com a máscara

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    User Contributed Notes 5 notes

    up
    8
    maskedcoder at hotmail dot com
    17 years ago
    useful for finding beginning of quotes and/or tags in a variable containing html.
    $pos = strcspn($data, '<"\'');
    will find the first occurance of either the beginning of a tag, or a double- or single-quoted string.
    up
    7
    AT-HE (at_he AT hotmai1 DOT com)
    17 years ago
    this function can be used like strspn(), except while that can be used to compare a string with an allowed pattern, this one can be use to compare a string with a FORBIDDEN pattern

    so, to know if any forbidden character has a position inside our string, we can use (not tested with backslashes)...

    <?php
    // LARGE VERSION
    $forbidden="\"\\?*:/@|<>";
    if (    strlen($filename) != strcspn($filename,$forbidden)) {
    echo     "you cant create a file with that name!";
    }

    // SHORT VERSION
    if (strlen($filename) - strcspn($filename,"\"\\?*:/@|<>")) {
    echo     "i told you, you cant create that file";
    }
    ?>
    up
    1
    legacyprog at routinz dot net
    12 years ago
    When you use the third parameter remember that the function will return the number of characters it bypassed, which will *not* be the position in your source string. It's a simple fix to just add your third parameter value to the function result to get the position in the first string where the scan stopped, but I didn't think of it at first.
    up
    0
    nospam at nospam dot com
    7 years ago
    It might not be clear from the example, that

    strcspn('abcdhelloabcd', 'abcd', -9, -5) == 4

    because it's only evaluating 'hell' which doesn't contain any mask, so returns strlen('hell').
    up
    0
    Anonymous
    13 years ago
    strcspn() can also be thought of as analogous to the following regular expression:
    <?php
    // where ... represents the mask of characters
    preg_match('/[^ ...]/', substr($subject, $start, $length) );
    ?>
    By this analogy, strcspn() can be used in place of some regular expressions to match a pattern without the overhead of a regex engine -- for example, ways to verify if an input string represents a binary value:
    <?php
    preg_match    ('/^[01]+$/i', $subject);
    // or...
    !preg_match('/[^01]/i', $subject);

    // ...or using strcspn()
    !strcspn($subject, '01');
    ?>
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