nullshell ========= **do nothing but print keep alive characters, can be used for login shell** This is a minimal program that does nothing but print some characters (namely version information and time&date string) every now and then. It is intended to be used for login shell with accounts accessible via secure shell that are used for secure tunneling but should not allow to execute commands. Requirements ------------ To compile and run `nullshell` you need: * nothing (this is plain C) * [markdown](https://daringfireball.net/projects/markdown/) (HTML documentation) Additionally it is expected to have `make` and a C compiler around to successfully compile. Build and install ----------------- Building and installing is very easy. Just run: > make followed by: > make install This will place an executable at `/usr/bin/nullshell`. Usage ----- To create a new user `user` with `nullshell` as login shell just run: > useradd -s /usr/bin/nullshell user Or to make `nullshell` the login shell for an existing user `user`: > usermod -s /usr/bin/nullshell user Make sure `/usr/bin/nullshell` is listed in `/etc/shells` if your system expects this. License and warranty -------------------- This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the [GNU General Public License](COPYING.md) for more details. ### Upstream URL: [GitHub.com](https://github.com/eworm-de/nullshell#nullshell) Mirror: [eworm.de](https://git.eworm.de/cgit.cgi/nullshell/) [GitLab.com](https://gitlab.com/eworm-de/nullshell#nullshell)