strcspn

(PHP 4, PHP 5)

strcspn — マスクにマッチしない最初のセグメントの長さを返す

説明

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

str1 において str2 の文字がどれも含まれていない最初のセグメントの長さを返します。

パラメータ

str1: 最初の文字列。
str2: 2 番目の文字列。
start: 調べ始める位置。
length: 調べる文字列の長さ。

返り値

セグメントの長さを返します。

変更履歴

バージョン	説明
4.3.0	`start` および `length` が追加されました。

注意

注意: この関数はバイナリデータに対応しています。

参考

strspn() - 指定したマスク内に含まれる文字からなる文字列の最初のセグメントの長さを探す

strip_tags

strcoll

Last updated: Fri, 06 Nov 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, 06 Nov 2009