为什么我尝试替换字符串中的字符失败？

Question

I have a string (taken from a MySQL database if it makes any difference) which looks normal enough:

Manufacture: <a href="http://www.x.com/">Blah</a>

The problem is that the space between Manufacture: and the <a> tag has a charcode of 194, not 32 as I would expect.

This is causing a preg_match with the following pattern to fail (please ignore the attempts to parse HTML with regex, I know it's not a good idea but this particular dataset is predictable enough to get away with it):

/Manufacture: *(<a[^>]*>([A-Za-z- 0-9]+)<\/a>)/i

If I replace the rogue space with a normal space character in a text editor and try again, the expression matches as expected, but I need to alter it programatically.

I tried str_replace:

$text = str_replace(chr(194), ' ', $text);

But the preg_match still fails. I then tried preg_replace:

$text = preg_replace('/[\xC2]/', ' ', $text);

But that doesn't work either, even though running that same pattern through preg_match does contain the expected match.

Does anyone have any ideas?

Answer 1

Can you please check the structure of the MySQL table where you get the contents of $text from? If the collation is utf8_general_ci or something like that then your string most likely contains a double-byte UNICODE character.

If that is the case then the PHP function iconv should do the trick. Here's the example from the PHP manual. The IGNORE option should remove the UNICODE character from the string.

<?php
$text = "This is the Euro symbol '€'.";

echo 'Original : ', $text, PHP_EOL;
echo 'TRANSLIT : ', iconv("UTF-8", "ISO-8859-1//TRANSLIT", $text), PHP_EOL;
echo 'IGNORE   : ', iconv("UTF-8", "ISO-8859-1//IGNORE", $text), PHP_EOL;
echo 'Plain    : ', iconv("UTF-8", "ISO-8859-1", $text), PHP_EOL;

?>

The above example will output something similar to:

Original : This is the Euro symbol '€'.
TRANSLIT : This is the Euro symbol 'EUR'.
IGNORE   : This is the Euro symbol ''.
Plain    :
Notice: iconv(): Detected an illegal character in input string in .\iconv-example.php on line 7
This is the Euro symbol '