# documentation:2.0:customfunctions
Keywords: documentation,2.0,customfunctions

# Custom functions

Custom functions allow one to extend LL::NG, they can be used in headers, rules or form replay data.

## Write custom functions library

Create your Perl module with custom functions. You can name your module as you want, for example `SSOExtensions.pm`:

    vi /root/SSOExtensions.pm

    package SSOExtensions;

    sub function1 {
      my (@args) = @_;

      # Your nice code here
      return $result;
    }

    1;

## Import custom functions in LemonLDAP::NG

### Declare module in handler server

#### Apache

Your module has to be loaded by Apache (for example after Handler load):

    # Perl environment
    PerlRequire Lemonldap::NG::Handler
    PerlRequire /root/SSOExtensions.pm
    PerlOptions +GlobalRequest

#### FastCGI server (Nginx)

You've just to incicate to LLNG FastCGI server the file to read using either `-f` option or `CUSTOM_FUNCTIONS_FILE` environment variable. Using packages, you just have to modify your `/etc/default/llng-fastcgi-server` (or `/etc/default/lemonldap-ng-fastcgi-server`) file:

    # Number of process (default: 7)
    #NPROC = 7

    # Unix socket to listen to
    SOCKET=/var/run/llng-fastcgi-server/llng-fastcgi.sock

    # Pid file
    PID=/var/run/llng-fastcgi-server/llng-fastcgi-server.pid

    # User and GROUP
    USER=www-data
    GROUP=www-data

    # Custom functions file
    CUSTOM_FUNCTIONS_FILE=/root/SSOExtensions.pm

### Declare custom functions

Go in Manager, `General Parameters` » `Advanced Parameters` » `Custom functions` and set:

    SSOExtensions::function1

If your function is not compliant with Safe jail, you will need to disable the jail.

## Use it

You can now use your function in a macro, an header or an access rule, for example:

    Custom-Header => function1( $uid, $ENV{REMOTE_ADDR} )