Warning: This program is experimental and its interface is subject to change.
Name
nix fmt
- reformat your code in the standard style
Synopsis
nix fmt
[option...] args...
Examples
With nixpkgs-fmt:
# flake.nix
{
outputs = { nixpkgs, self }: {
formatter.x86_64-linux = nixpkgs.legacyPackages.x86_64-linux.nixpkgs-fmt;
};
}
-
Format the current flake:
$ nix fmt
-
Format a specific folder or file:
$ nix fmt ./folder ./file.nix
With nixfmt:
# flake.nix
{
outputs = { nixpkgs, self }: {
formatter.x86_64-linux = nixpkgs.legacyPackages.x86_64-linux.nixfmt;
};
}
- Format specific files:
$ nix fmt ./file1.nix ./file2.nix
With Alejandra:
# flake.nix
{
outputs = { nixpkgs, self }: {
formatter.x86_64-linux = nixpkgs.legacyPackages.x86_64-linux.alejandra;
};
}
-
Format the current flake:
$ nix fmt
-
Format a specific folder or file:
$ nix fmt ./folder ./file.nix
Description
nix fmt
will rewrite all Nix files (*.nix) to a canonical format
using the formatter specified in your flake.
Options
--debugger
start an interactive environment if evaluation fails
Common evaluation options:
-
--arg
name expr
Pass the value expr as the argument name to Nix functions. -
--argstr
name string
Pass the string string as the argument name to Nix functions. -
--eval-store
store-url
The Nix store to use for evaluations. -
--impure
Allow access to mutable paths and repositories. -
--include
/-I
path
Add path to the list of locations used to look up<...>
file names. -
--override-flake
original-ref resolved-ref
Override the flake registries, redirecting original-ref to resolved-ref.
Common flake-related options:
-
--commit-lock-file
Commit changes to the flake's lock file. -
--inputs-from
flake-url
Use the inputs of the specified flake as registry entries. -
--no-registries
Don't allow lookups in the flake registries. This option is deprecated; use--no-use-registries
. -
--no-update-lock-file
Do not allow any updates to the flake's lock file. -
--no-write-lock-file
Do not write the flake's newly generated lock file. -
--override-input
input-path flake-url
Override a specific flake input (e.g.dwarffs/nixpkgs
). This implies--no-write-lock-file
. -
--recreate-lock-file
Recreate the flake's lock file from scratch. -
--update-input
input-path
Update a specific flake input (ignoring its previous entry in the lock file).
Options that change the interpretation of installables:
-
--derivation
Operate on the store derivation rather than its outputs. -
--expr
expr
Interpret installables as attribute paths relative to the Nix expression expr. -
--file
/-f
file
Interpret installables as attribute paths relative to the Nix expression stored in file. If file is the character -, then a Nix expression will be read from standard input. Implies--impure
.