Just Programmer's Manual

Positional Arguments

If positional-arguments is true, recipe arguments will be passed as positional arguments to commands. For shell recipes, argument $0 will be the name of the recipe.

For example, running this recipe:

set positional-arguments

@foo bar:
  echo $0
  echo $1

Will produce the following output:

$ just foo hello
foo
hello

When using an sh-compatible shell, such as bash or zsh, $@ expands to the positional arguments given to the recipe, starting from one. When used within double quotes as "$@", arguments including whitespace will be passed on as if they were double-quoted. That is, "$@" is equivalent to "$1" "$2"… When there are no positional parameters, "$@" and $@ expand to nothing (i.e., they are removed).

This example recipe will print arguments one by one on separate lines:

set positional-arguments

@test *args='':
  bash -c 'while (( "$#" )); do echo - $1; shift; done' -- "$@"

Running it with two arguments:

$ just test foo "bar baz"
- foo
- bar baz

Positional arguments may also be turned on a per-recipe basis with the [positional-arguments] attribute^1.29.0:

[positional-arguments]
@foo bar:
  echo $0
  echo $1

Note that PowerShell does not handle positional arguments in the same way as other shells, so turning on positional arguments will likely break recipes that use PowerShell.

If using PowerShell 7.4 or better, the -CommandWithArgs flag will make positional arguments work as expected:

set shell := ['pwsh.exe', '-CommandWithArgs']
set positional-arguments

print-args a b c:
  Write-Output @($args[1..($args.Count - 1)])