gitignore-merge

A command-line tool that intelligently merges multiple .gitignore files on a per-section basis.

日本語

Installation

go install github.com/taku-o/gitignore-merge/cmd/gitignore-merge@latest

Or build from source:

git clone <repository-url>
cd gitignore-merge
make build

Usage

gitignore-merge <file1> <file2> [file3...]

• Specify two or more .gitignore file paths as arguments
• The merge result is printed to stdout
• Use redirection to write to a file

gitignore-merge project.gitignore template.gitignore > .gitignore

Merge Rules

Section Matching

Comment lines starting with # are recognized as section headers. Section names are compared by stripping all leading # characters and spaces from the first line of the header.

The following are all treated as the same section name "Node":

# Node
## Node
#Node

Merge Priority

The first file serves as the base, and subsequent files are merged into it in order.

• Same-name sections: Patterns from subsequent files are added to the matching section in the base
• New sections: Sections not present in the base are appended to the end

Deduplication

Exactly matching patterns within the same section are deduplicated.

Conflict Resolution

When a pattern and its negation conflict (e.g., path and !path), the base file (first file) takes priority.

Examples:

• If the base has *.log, a subsequent !*.log is ignored
• If the base has !*.log, a subsequent *.log is ignored

Example

Input

file1.gitignore (base):

# Node
node_modules/
dist/

# Logs
*.log
!important.log

# OS
.DS_Store
Thumbs.db

file2.gitignore:

# Node
node_modules/
build/

# Logs
*.log
!debug.log

# IDE
.vscode/
.idea/

Run

gitignore-merge file1.gitignore file2.gitignore

Output

# Node
node_modules/
dist/

build/

# Logs
*.log
!important.log

!debug.log

# OS
.DS_Store
Thumbs.db

# IDE
.vscode/
.idea/

In this output:

• # Node section: node_modules/ was deduplicated, build/ was added
• # Logs section: *.log was deduplicated, !debug.log was added
• # OS section: exists only in the base, kept as-is
• # IDE section: exists only in file2, appended to the end