ysh

ysh Plugin

Oils for Unix is a single native binary with two shells: osh (bash/POSIX-compatible) and ysh (modern language with typed data and structured pipelines).

Commands

Shell

• ysh shell exec "<code>" — Run YSH code
• ysh osh exec "<code>" — Run bash-compatible code with OSH
• ysh script run <file> — Execute a .ysh script
• ysh self version — Show version
• ysh _ _ — Passthrough to ysh CLI

Usage Examples

• "Run my bash script under a stricter shell"
• "Write a script with real dicts and JSON output"
• "Syntax-check this shell file"

Installation

# tarball: https://www.oils.pub/release/latest/
./configure && _build/oils.sh && sudo ./install
# or: mise use ysh

Examples

ysh -c 'var x = {"k": [1,2]}; json write (x)'
ysh -c 'proc greet(name) { echo "hi $name" }; greet world'
osh -c 'for f in *.sh; do bash -n "$f"; done'   # bash-compatible
ysh -n script.ysh                               # syntax check only

Key Features

• OSH runs most bash scripts unchanged, with better errors (osh -n checks)
• YSH: expressions, Dict/List types, json write/json read pipelines
• Single static C++ binary — no dependencies, fast startup
• Egg expressions, procs vs funcs, honest error messages