vix fmt

vix fmt formats C++ source files using clang-format.

Use it when you want consistent formatting across your project.

Usage

vix fmt [options] [files...]

What it does

vix fmt scans files or directories and applies clang-format. It can format one file, multiple files, or directories, and check formatting without changing files.

Basic usage

# Format the default project folders
vix fmt

# Format specific folders
vix fmt src include

# Format one file
vix fmt main.cpp

# Check whether a file is formatted
vix fmt main.cpp --check

# Ignore a path
vix fmt src --ignore=build --ignore=vendor

Default behavior

If no files or directories are provided, vix fmt scans src/ and include/. A normal project can usually be formatted with:

vix fmt

Check mode

Use --check when you only want to verify formatting:

vix fmt --check
vix fmt src include --check
vix fmt main.cpp --check

This is useful before committing or in CI.

Ignore paths

vix fmt src include --ignore=build
vix fmt src include --ignore=build --ignore=vendor

Common ignored folders: build, vendor, third_party, .vix, dist

Project formatting file

If a .clang-format file exists, clang-format uses it automatically. Then vix fmt uses the formatting rules from .clang-format.

Options

Option	Description
--check	Check if files are formatted without modifying them.
--ignore <path>	Ignore a file or path pattern. Repeatable.
-q, --quiet	Suppress non-essential output.
-h, --help	Show command help.

Common workflows

# Format the current project
vix fmt

# Check formatting before commit
vix fmt --check

# Format source and headers
vix fmt src include

# Format one file
vix fmt src/main.cpp

# Format while ignoring build outputs
vix fmt src include --ignore=build --ignore=.vix

CI usage

In CI, use check mode:

vix fmt --check
vix check --tests

Common mistakes

Forgetting --check in CI

This modifies files:

vix fmt

In CI, prefer:

vix fmt --check

Formatting generated or vendor files

vix fmt src include --ignore=vendor --ignore=build --ignore=.vix

Recommended project task

{
  "tasks": {
    "fmt": "vix fmt",
    "fmt:check": "vix fmt --check"
  }
}

Related commands

Command	Purpose
vix make	Generate C++ files
vix check	Validate build, tests, runtime, and sanitizers
vix tests	Run tests
vix task	Run reusable project tasks
vix build	Compile the project

Next step

Continue with project cleanup.

Open the vix clean guide