Gqrx is a Software-defined radio receiver software for Linux and Mac.

Remote control over TCP

Gqrx has a setting called Remote control that allows an external program to connect to it and issue commands.

By default, the port is 7356, and only connections from are allowed. This is a sensible default for giving local applications control without allowing external commands.

The protocol is a human-readable, line-delimited ASCII protocol. Commands and their arguments are delimited by a space character. The responses are also sent as lines.

Read the current frequency

  • Send line f.
  • Read a line from the socket. Convert to an integer. The integer is the center frequency in Hz.

Set the frequency

  • Send line F freq where freq is the frequency in Hz.
  • Read a response line from the socket, and discard it.