rl_custom_function

This is a LD_PRELOAD hack to enable you to inject custom functions in to any readline application.

http://web.mit.edu/gnu/doc/html/rlman_2.html#SEC23

Custom functions are usually added to readline at compile-time of the application, but this becomes tricky if you want to add a custom readline function to many readline-enabled applications (python, irb etc) without patching and compiling everything from source yourself.

Building

Run:

cargo build --release

The resulting lib should be at: target/release/librl_custom_function.so

Usage

Custom functions can be loaded via readline init files (e.g. ~/.inputrc, or equivalently rl_parse_bind) using a $include directive like so:

$include function FUNCTION PATH
"\C-g": FUNCTION

where PATH is a path to shared object that exports a function conforming to:

typedef int rl_command_func_t (int, int);

Example

There is a very simple example in example/hello_world.rs.

Compile the function by running:

rustc example/hello_world.rs -o hello_world.so

Then add to your ~/.inputrc:

$include function hello_world /path/to/hello_world.so
"\C-g": hello_world

Run something interactive that uses readline, e.g. python:

LD_PRELOAD=target/release/librl_custom_function.so python

... and press control-g.