Issue

In the PHP code, using the mb_strlen method, an error outputs as bellow.

Call to undefined function mb_strlen()

Solution

It needs to enable mbstring.

Linux/Unix

We can configure PHP again or add mbstring extension.

1. Configure PHP

When configure PHP, add --enable-mbstring .

$ ./configure --prefix=/opt/php --enable-mbstring
$ make
$ sudo make install

2. Add mbstring extension

In PHP source folder.

$ cd ext/mbstring
$ ./configure --prefix=/opt/php-5.4.45 --with-php-config=/opt/php-5.4.45/bin/php-config
$ make
$ sudo make install

Edit php.ini, add new line extension=mbstring.so.

extension=mbstring.so

Windows

In php.ini, remove the ; symbol before extension=php_mbstring.dll.

extension=php_mbstring.dll