Subsystems can be defined in the sshd2_config file using the following syntax.

subsystem-<name>      argument

The argument is the command which will be executed when the subsystem is requested.

$ sshg3 user@remote -s <name>

The argument can be a list of commands separated with a semicolon (;), or it can, for example, refer to a script.

One example of a subsystem is sftp.

subsystem-sftp      /opt/tectia/libexec/sft-server-g3