btfmt

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A formatter for bpftrace scripts with VS Code integration.

Features

• Format bpftrace scripts with consistent indentation, spacing, and structure
• VS Code extension with bundled binary - install and use immediately
• Language Server Protocol (LSP) support for editor integration
• Configurable formatting rules via JSON configuration file
• Preserves comments and shebangs

Installation

VS Code Extension (Recommended)

Install the btfmt-lsp extension from the Releases page:

1. Download the .vsix file for your platform (e.g., btfmt-lsp-0.0.2@linux-x64.vsix)
2. In VS Code, press Ctrl+Shift+P and run "Extensions: Install from VSIX..."
3. Select the downloaded file

The extension includes the btfmt binary - no additional installation required.

CLI Binary

Download the pre-built binary from Releases:

Platform	File
Linux x64	btfmt-linux-amd64.tar.gz
Linux ARM64	btfmt-linux-arm64.tar.gz
macOS x64	btfmt-darwin-amd64.tar.gz
macOS ARM64	btfmt-darwin-arm64.tar.gz
Windows x64	btfmt-windows-amd64.zip
Windows ARM64	btfmt-windows-arm64.zip

Extract and add to your PATH:

tar -xzf btfmt-linux-amd64.tar.gz
sudo mv btfmt /usr/local/bin/

Build from Source

go install github.com/fanyang89/bpftrace-formatter/cmd/btfmt@latest

Or clone and build:

git clone https://github.com/fanyang89/bpftrace-formatter.git
cd bpftrace-formatter
go build ./cmd/btfmt

Usage

Format a file

btfmt script.bt          # Print formatted output to stdout
btfmt -w script.bt       # Write result back to file
btfmt -w *.bt            # Format multiple files

Example

Before:

#!/usr/bin/env bpftrace
tracepoint:syscalls:sys_enter_openat{printf("openat: %s\n",str(args.filename));}
tracepoint:syscalls:sys_enter_openat/pid==1234/{@opens[pid]=count();}

After:

#!/usr/bin/env bpftrace

tracepoint:syscalls:sys_enter_openat
{
    printf("openat: %s\n", str(args.filename));
}

tracepoint:syscalls:sys_enter_openat /pid == 1234/
{
    @opens[pid] = count();
}

CLI Options

btfmt [options] <file.bt> [file2.bt ...]

Options:
  -w                     Write result to source file
  -i                     Edit files in place (same as -w)
  -c, -config <file>     Path to configuration file
  -v, -verbose           Enable verbose output
  -generate-config       Generate default configuration file
  -version               Show version information
  -help                  Show help message

Configuration

btfmt looks for configuration in this order:

1. File specified with -config flag
2. .btfmt.json in current directory or parent directories
3. ~/.btfmt.json in home directory
4. Built-in defaults

Generate a default configuration file:

btfmt -generate-config

Example .btfmt.json:

{
  "indent": {
    "size": 4,
    "use_spaces": true
  },
  "spacing": {
    "around_operators": true,
    "around_commas": true
  },
  "line_breaks": {
    "empty_lines_between_probes": 1
  },
  "blocks": {
    "brace_style": "next_line"
  }
}

Configuration Options

Section	Option	Default	Description
indent	size	4	Spaces/tabs per indent level
indent	use_spaces	true	Use spaces instead of tabs
spacing	around_operators	true	Space around =, +, -, etc.
spacing	around_commas	true	Space after commas
spacing	before_block_start	true	Space before {
spacing	after_keywords	true	Space after if, while, etc.
line_breaks	empty_lines_between_probes	1	Empty lines between probe blocks
line_breaks	empty_lines_after_shebang	1	Empty lines after shebang
blocks	brace_style	"next_line"	"same_line", "next_line", or "gnu"

VS Code Extension

The VS Code extension provides:

• Syntax highlighting for .bt files
• Format on save (enable in VS Code settings)
• Format document command (Shift+Alt+F)

Extension Settings

Setting	Default	Description
btfmt.serverPath	btfmt	Path to btfmt binary (uses bundled binary by default)
btfmt.configPath	""	Path to .btfmt.json configuration file

License

Unlicense (Public Domain)