This code
print mb_substr(\'éxxx\', 0, 1);
prints an empty space :(
It is supposed to print the first character, é
. This seems
Try passing the encoding parameter to mb_substr, as such:
print mb_substr('éxxx', 0, 1, 'utf-8');
The encoding is never detected automatically.
In practice I've found that, in some systems, multi-byte functions default to ISO-8859-1 for internal encoding. That effectively ruins their ability to handle multi-byte text.
Setting a good default will probably fix this and some other issues:
mb_internal_encoding('UTF-8');