Download and install the PERL script to /usr/local/sbin (or any path location in env). Name as : vodasms. o2sms ... etc
Install required PERL modules with the following commands.
pkg_add -r p5-LWP-Authen-Wsse pkg_add -r p5-Net-SSLeay pkg_add -r p5-IO-Socket-SSL pkg_add -r p5-Crypt-SSLeay pkg_add -r p5-Net-SSLeay pkg_add -r p5-HTML-Parser pkg_add -r p5-URI pkg_add -r p5-Lingua-EN-Squeeze