[xeeZ]

https://github.com/Zeex/samp-rcon

It's a console app like the original rcon.exe but also compiles and runs on Linux (thanks to Boost). It can work in two modes: interactive and not. In interactive mode you run the program once and send multiple commands by typing them in and pressing Enter after each one. In non-interactive mode it sends the specified command (the -c or --command option), displays its output and exits.

Code:

Usage: rcon [options]

Available options:
  -h [ --help ]                  show this message and exit
  -s [ --host ] arg (=localhost) set server IP address or hostname
  -p [ --port ] arg (=7777)      set server port
  -w [ --password ] arg          set RCON password
  -c [ --command ] arg           set command to be executed
  -t [ --timeout ] arg (=150)    set response timeout (in milliseconds)
  -i [ --interactive ]           run in interactive mode

Download binaries here.