strcspn

(PHP 4, PHP 5)

strcspn — Ermittelt die Anzahl der nicht übereinstimmenden Zeichen

Beschreibung

int strcspn ( string $str1 , string $str2 [, int $start [, int $length ]] )

Gibt die Länge von str1 zurück, bis zu der kein Zeichen aus str2 vorkommt.

Parameter-Liste

str1: Die erste Zeichenkette.
str2: Die zweite Zeichenkette.
start: Die Anfangsposition der zu untersuchenden Zeichenkette.
length: Die Länge der zu untersuchenden Zeichenkette.

Rückgabewerte

Gibt die Länge des gefundenen Segments als Integerwert zurück.

Changelog

Version	Beschreibung
4.3.0	Die Parameter `start` und `length` wurden eingeführt.

Anmerkungen

Hinweis: Diese Funktion ist binary safe.

Siehe auch

strspn() - Ermittelt die Länge der am Anfang übereinstimmenden Zeichen

strip_tags

strcoll

Last updated: Fri, 30 Oct 2009

add a note User Contributed Notes
strcspn

Anonymous
16-Oct-2009 05:55


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');

?>

Dmitry Mazur
04-Mar-2009 06:17


The second parameter simply is the set of the "stop"-characters.

In other words, this function will return the index (starting from 0) of a first occurence of the stop-character.

PHP at NospamImmortalSoFar dot com
08-Oct-2006 01:31


Also useful for breaking down expressions - for example parsing SQL: values ('this', fn("that,)()", 4))



$sep = strcspn ($list, "'\"`");     //    Start of quoted string

$list = substr ($list, $sep);

$find = substr ($list, 0, 1);

while (($sep = strpos ($list, $find, $sep+1)) > 0 && substr ($list, $sep-1, 1) == '\\')

    {}

//  $sep now spans the entire string, regardless of embedded quotes



Once the strings have been removed, an expression can then be parsed for commas and brackets without worrying about them:



while ($out != '')

{

    $sep = strcspn ($list, "(),");      //  Next seperator

...

}

AT-HE (at_he AT hotmai1 DOT com)
27-Dec-2005 10:07


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";

}

?>

maskedcoder at hotmail dot com
10-Oct-2005 11:13


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.

add a note

strip_tags

strcoll

Last updated: Fri, 30 Oct 2009