Shell Aliases

PiG runs every shell command in a new, non-interactive Bash process. Non-interactive Bash does not expand aliases, and it does not read the startup files that your interactive terminal reads. An alias that works in your terminal therefore fails inside PiG until you load it.

Two settings control this. shellPath chooses the Bash executable. shellCommandPrefix runs setup before every command.

Which shell runs a command

Command source	Shell
The model calls the built-in `bash` tool	The Bash executable that PiG resolves
You type `!command` or `!!command` in the editor	The same Bash executable
An RPC client sends the `bash` command	The same Bash executable
The model calls the `powershell` tool on Windows	PowerShell
An extension provides or replaces a shell tool	Whatever that extension runs

PiG starts Bash as bash -c "<command>". It resolves the executable in this order:

shellPath from settings, if you set it. PiG reports Custom shell path not found when the file does not exist.
On Linux and macOS: /bin/bash, then bash on your PATH, then sh.
On Windows: Git Bash under Program Files, then bash.exe on your PATH. See Windows setup.

PiG does not use your $SHELL. The tools send Bash syntax, so a zsh or fish login shell is not a substitute.

Choose a Bash executable

Set shellPath in ~/.pig/agent/settings.json to use a specific Bash:

{
  "shellPath": "~/.local/bin/bash"
}

PiG expands a leading ~/. On Windows, write backslashes twice or use forward slashes:

{
  "shellPath": "C:\\cygwin64\\bin\\bash.exe"
}

Run /reload after you change the setting.

Run setup before every command

Set shellCommandPrefix to run shell code before each command. PiG applies it to the bash tool, to ! and !! commands, and to RPC bash commands:

{
  "shellCommandPrefix": "export CI=1"
}

PiG joins the prefix and the command with a newline. The prefix runs again for every command, so keep it fast and make sure it never waits for input.

PiG still reads commandPrefix, the former name of this setting.

Enable aliases

Keep the aliases that PiG needs in a small Bash file instead of loading your whole interactive configuration. Create ~/.bash_aliases:

alias ll='ls -la'
alias gs='git status --short'

Turn on alias expansion and load the file:

{
  "shellCommandPrefix": "shopt -s expand_aliases\nsource ~/.bash_aliases"
}

Run /reload, then test an alias from the editor:

!ll

The output matches ls -la.

Write aliases in Bash syntax. Do not load ~/.zshrc into Bash. Zsh options, functions and plugins often fail to parse in Bash, or they behave differently there.

Troubleshooting

The prefix works for `!` but not for an extension's tool

shellCommandPrefix applies to PiG's built-in Bash execution only. An extension that replaces the bash tool, or that runs its own shell, sets up its own environment. Read that extension's documentation.

`shopt: command not found`

PiG fell back to sh, or shellPath points to a shell that is not Bash. Install Bash, or set shellPath to a Bash executable.

Every command hangs

A command in shellCommandPrefix waits for input. Remove interactive commands from the prefix.

An alias works in the terminal but not in PiG

Check that shellCommandPrefix turns on expand_aliases before it loads the alias file. Bash reads each alias definition before it runs the next line, so the alias must be defined on a line before the command that uses it. PiG puts the prefix on its own lines before the command, which meets this rule.

Settings lists shellPath and shellCommandPrefix.
Windows setup covers the Windows shell defaults.

PiG Documentation