rlwrap: readline Wrapper Program

Page Trail: [[ rlwrap: readline Wrapper Program ]]
2011-12-28 17:56

Dealing with a basic command-line prompt in a loop can be painful, so many programs, such as shells, interactive programming languages and debuggers, provide a more featureful prompt. For example, pressing the up and down arrows in a good prompt will flip through previously entered input lines. Programs will often make use of the GNU readline library for this functionality.

If you need to use a program that only has a basic prompt, you may be able to wrap it with the program rlwrap to get some more advanced features. From the man page:

rlwrap runs the specified command, intercepting user input in order to provide readline's line editing, persistent history and completion.

[...]

There are many options to add (programmable) completion, handle multi-line input, colour and re-write prompts. If you don't need them (and you probably don't), you can skip the rest of this manpage.

For example, I recently used rlwrap with jdb, the Java debugger, and Ikarus, a Scheme compiler.