iconv_strlen
(PHP 5)
iconv_strlen — Returns the character count of string
Description
int iconv_strlen
( string
$str
[, string $charset = ini_get("iconv.internal_encoding")
] )
In contrast to strlen(),
iconv_strlen() counts the occurrences of characters
in the given byte sequence str on the basis of
the specified character set, the result of which is not necessarily
identical to the length of the string in byte.
Parameters
-
str -
The string.
-
charset -
If
charsetparameter is omitted,stris assumed to be encoded in iconv.internal_encoding.
Return Values
Returns the character count of str, as an integer.
Коментарии
If iconv_strlen is passed a UTF-8 string containing badly formed sequences, it will return FALSE. This is in contrast to mb_strlen of the behaviour of utf8_decode, which strip out any bad sequences;
<?php
# UTF-8 string containing bad sequence: \xe9
$str = "I?t?rn?ti?n\xe9?liz?ti?n";
print "mb_strlen: ".mb_strlen($str,'UTF-8')."\n";
print "strlen/utf8_decode: ".strlen(utf8_decode($str))."\n";
print "iconv_strlen: ".iconv_strlen($str,'UTF-8')."\n";
?>
Displays;
mb_strlen: 20
strlen/utf8_decode: 20
iconv_strlen:
(PHP 5.0.5)
As such it is being "stricter" than mb_strlen and it may mean you need to check for invalid sequences first. A quick way to check is to exploit the behaviour of the PCRE extension (see notes on pattern modifiers);
<?php
if (preg_match('/^.{1}/us',$str,$ar) != 1) {
die("string contains invalid UTF-8");
}
?>
A slower but stricter check (regex) can be found at: http://www.w3.org/International/questions/qa-forms-utf-8
Similiar applies to iconv_substr, iconv_strpos and iconv_strrpos
Notice there is a disconnect:
>If charset`parameter is omitted, str is assumed to be encoded in iconv.internal_encoding.
But clicking on the iconv.internal_encoding link (https://www.php.net/manual/en/iconv.configuration.php), the docs indicate that iconv.internal_encoding is deprecated since 5.6.