zish

A fast shell for Linux. Runs your bash scripts, and can sandbox what it runs.

Install

paru -S zish                                    # Arch
nix profile install github:rotkonetworks/zish   # Nix
sudo apt install ./zish_*_amd64.deb             # Debian, Ubuntu, Proxmox

The .deb and plain binaries are on the releases page.

Use

zish                # start it
zish -c 'echo hi'   # run one command
man zish            # everything else

Bash syntax works: pipes, $(…), $((…)), [[ ]], arrays, functions, job control.

Interactive extras:

• vim and emacs keys together (Esc for vim)
• syntax highlighting and a git prompt
• grey suggestions from history (Right to accept)

Missing: associative arrays, zsh-only syntax.

Speed

About 1.2 to 1.8x faster than bash. Check it yourself with ./bench.sh.

Feats

Small built-in tools, so you don't reach for Python:

calc '2^0.5'                 # 1.4142135623730951
cnt file.txt                 # line count
pk -t 5 build.log            # last 5 lines
ls *.log | para grep ERROR {}   # run in parallel

feat list shows what you have. gf install <name> adds more. A feat never replaces a real command with the same name.

Sandbox

zish --profile readonly -c 'make test'   # can't write anything
zish --profile workdir  -c 'make build'  # can only write in this directory

The kernel enforces it (Landlock + seccomp), so child programs can't get around it. It doesn't stop reads or network access. See docs/security.md and, for running AI agents inside it, docs/agents.md.

Contributing

./tests/regress.sh   # must stay green

Add a test for whatever you fix.

MIT licensed.