Cicada Unix Shell

Cicada is a simple, semi-toy Unix shell written in Rust. And I use it as my default login shell.

Documents

• Environment Variables
• Built-in Commands
• Completion
• RC File
• History

Features

run programs and pipelines

$ ls | head -n3
Desktop
Documents
Downloads

$ echo foo bar | awk -F " " '{print $2, $1}'
bar foo

with redirections

$ ls file-not-exist 2>&1 | wc > e.txt
$ cat e.txt
       1       7      46

command substitution

$ ls -l `which sh`
-r-xr-xr-x  1 root  wheel  630464 Mar 23 07:57 /bin/sh

run multiple commands (with logical)

$ echo foo; echo bar
foo
bar

$ echo foo && echo bar
foo
bar

$ echo foo || echo bar
foo

shell expansions

$ echo sp{el,il,al}l
spell spill spall

$ echo $SHELL
/usr/local/bin/cicada

$ echo *
Cargo.lock Cargo.toml LICENSE Makefile README.md src target

do math arithmetic directly in the shell!

$ 1 + 2 * 3 - 4
3
$ (1 + 2) * (3 - 4) / 8.0
-0.375

Install Cicada

Note: Rust environment is needed for installation.

You can try cicada out without installing it by checking out the repository and run cargo run in its root directory.

$ git clone https://github.com/mitnk/cicada
$ cd cicada
$ cargo run

install from code repository

If you've checked out the cicada repository, you can do this:

$ make install

This will install cicada under your /usr/local/bin. Use sudo if needed.

install via cargo crates

$ cargo install -f cicada

This will install cicada into ~/.cargo/bin/.

Set cicada as your login shell

Appending /usr/local/bin/cicada into your /etc/shells, then run

$ chsh -s /usr/local/bin/cicada

To do list

• job controls (Ctrl-Z, fg, bg etc)
• and less...

Won't do list

• functions
• Windows support
• and more...