Script Execution

By default, Miso runs all scripts with sh.


# scripts/deploy.sh
 
echo "Deploying..."
pnpm run build

Scripts with a .sh or .bash extension run with sh. Scripts with no recognized extension (e.g. scripts/deploy with no extension) also default to sh.

Changing the Interpreter

You can run scripts with a different interpreter in three ways:

1. Use a Different File Extension

Miso selects the interpreter based on the file extension when no shebang is present:

Extension	Interpreter	Notes
`.sh`, `.bash`	`sh`	POSIX shell (default)
`.zsh`	`zsh`	Z shell
`.js`, `.mjs`	`node`	Node.js
`.ts`	`ts-node`	TypeScript (requires ts-node)
`.py`	`python3`	Python 3
`.rb`	`ruby`	Ruby
`.pl`	`perl`	Perl
`.lua`	`lua`	Lua
`.php`	`php`	PHP

2. Configure the Default Shell in miso.json

For scripts with no recognized extension, you can override the default sh in miso.json:


{
    "shell": "bash"
}

The shell field applies when neither shebang nor extension specifies an interpreter. Leave it unset to use sh.

3. Use a Shebang

If the first line starts with #!, Miso uses the specified interpreter. The shebang takes precedence over extension-based detection:


#!/usr/bin/env node
// Your JavaScript code here
console.log("Running with Node.js");


#!/usr/bin/env python3
# Your Python code here
print("Running with Python")

Interpreter Requirements

Make sure the required interpreter is installed and available in your PATH:


which node
which python3
which ruby

Error Handling

If a script exits with a non-zero status code, Miso will display the error and exit with the same code:


if [ -z "$1" ]; then
  echo "Error: Environment required"
  exit 1
fi

This ensures proper error propagation in CI/CD pipelines and build tools.