Using iconv() to check for invalid UTF-8 characters: Detected an illegal character in input string

3
votes

I am using iconv() to check if a string contains non-valid UTF-8 characters.

$valid = $string == iconv('UTF-8', 'UTF-8//IGNORE', $string);

However, this still throws the error: "iconv(): Detected an illegal character in input string"

To the best of my knowledge this should not be possible using the //IGNORE flag?

I'm using PHP 5.5.9-1ubuntu4.6 on Ubuntu 14.04.1 LTS

1
phputf-8character-encoding
Possible duplicate of iconv UTF-8//IGNORE still produces "illegal character" error – HPierce

1 Answers

4
votes

Another answer provides a better answer for why iconv() is throwing an error:

The output character set (the second parameter) should be different from the input character set (first param). If they are the same, then if there are illegal UTF-8 characters in the string, iconv will reject them as being illegal according to the input character set.

Taken from a comment in the PHP manual, you can detect if a string is encoded in UTF-8 with this function:

 $valid = mb_detect_encoding($str, 'UTF-8', true); // returns boolean.

More info on mb_detect_encoding();