esh is a lightweight command shell for embedded applications in C or Rust, small enough to be used for (and intended for) debug UART consoles on microcontrollers.
This readme describes esh and how to try it out. If you think you'd like to use it, see the guides in the source for informations on how to set it up and integrate it into your project: C header, Rust library.
There is a simple demo in the demo subdirectory, which can be compiled and
run on a unix-like system by moving into that directory and issuing the make
command. There are no dependencies other than libc and a compiler. Once built,
execute ./demo and try it out!
The Rust demo is in demo_rust, and can be compiled and run on a unix-like
system by moving into that directory and issuing cargo build and cargo run.
esh supports basic line editing, understanding the backspace key to delete characters, left and right arrow to move the insertion point, and Ctrl-C to ditch the entire line. Ctrl-left/right to move by a word is upcoming.
esh automatically splits a command string into arguments, and understands bash-style quoting. The command handler callback receives a simple argc/argv array of arguments, ready to use. Environment variables are not yet supported, but may be in the future.
If compiled in, esh supports history, allowing the use of the up/down arrow keys to browse previously entered commands and edit/re-issue them. A ring buffer is used to store a fixed number of characters, so more commands can be remembered if they're shorter.