1.4.1 The REPL

If poke is invoked with an interactive TTY connected to the standard input, it greets you with a welcome message, licensing information and such, and finally a prompt that looks like:

(poke)

At this point, the program is ready to be commanded. You are expected to introduce a line and press enter. At that point poke will examine the command, notify you if there is some error condition, process the line and maybe displaying something in the terminal.

Repeatedly typing complex commands can be tiresome. To help you, poke uses the readline library See GNU Readline Library. This provides shortcuts and simple keystrokes to repeat previous commands with or without modification, fast selection of file names and entries from other multiple choice contexts, and navigation within a command and among previous commands. When the REPL starts, the history of your previous sessions are loaded from the file .poke_history located in your home directory (if it exists).

There are several kinds of lines that can be provided in the REPL:

• A dot-command invocation, that starts with a dot character (.).
• A command invocation.
• A Poke statement.
• A Poke expression.

These are explained in the following sections.