This depends mostly on how you are running the server on a tcp port. When you run it from the command line you are getting the locale specified in your shell initialization file (.profile, .bashrc, etc depending which shell you are using). If you are running the server from inittab or from inetd or something similar, then you are getting the environment of whatever system user started the super-daemon. The easiest way to resolve it would be to add the appropriate environment variable to the top of the script (probably something like $ENV{LANG} = "fr_FR.UTF-8";)