Chess program which supports several variants
Documentation for sjeng is available in /usr/share/doc/sjeng/README. It is strongly recommended that you use sjeng in combination with some interface like xboard or eboard. Please read the documentation of xboard and eboard to find out how to enable variants.
There are no command line options for sjeng, but sjeng uses a configuration file, by default /etc/sjeng.rc. If present, the file ~/.sjeng/sjeng.rc in the user's home directory will be read instead of the system default. A well-documented example configuration can be found in /usr/share/doc/sjeng/examples/.
This manual page was written for the Debian distribution because the original program does not have a manual page.