Gitignore Builder

Build and merge .gitignore files using templates from github/gitignore with smart project detection.

When to Use

Invoke this skill when:

•User explicitly requests /gitignore or asks to create/update a .gitignore
•Detecting git init or a newly cloned repo without .gitignore
•User mentions ignoring files, not wanting to track certain files
•Observing git status output with files that should typically be ignored (e.g., node_modules/, .env, __pycache__/, *.log)

Workflow

Step 1: Determine Target Location

•Find the nearest .git directory to determine repo root
•If no .git found, ask user if they want to create a global gitignore at ~

Location Rules:

Situation	Action
Inside a repo, project-level requested	Use repo root (where `.git` is)
Inside a repo, global requested	Warn: "Global gitignore is recommended at `~/.gitignore`. You're currently inside a repo. Proceed here anyway?"
Not in a repo	Suggest creating global gitignore at `~/.gitignore`

Step 2: Detect Project Type

For project-level gitignore (basic detection):

Indicator File	Template
`package.json`	Node.gitignore
`requirements.txt`, `pyproject.toml`, `setup.py`, `Pipfile`	Python.gitignore
`Cargo.toml`	Rust.gitignore
`go.mod`	Go.gitignore
`composer.json`	Composer.gitignore
`Gemfile`	Ruby.gitignore
`pom.xml`	Maven.gitignore
`build.gradle`, `build.gradle.kts`	Gradle.gitignore
`*.swift`, `Package.swift`	Swift.gitignore
`.csproj`, `.sln`	VisualStudio.gitignore
`CMakeLists.txt`	CMake.gitignore
`Makefile` with C/C++ files	C.gitignore or C++.gitignore

For global gitignore (environment-aware detection):

Detection Method	Template (from Global/)
`uname` = Darwin	macOS.gitignore
`uname` = Linux	Linux.gitignore
Windows environment	Windows.gitignore
`.vscode/` exists or `code` command available	VisualStudioCode.gitignore
`.idea/` exists	JetBrains.gitignore
`vim` or `nvim` available	Vim.gitignore
`emacs` available	Emacs.gitignore

Step 3: Present Recommendations

Show detected templates and ask for confirmation:

code

Detected project root: /path/to/repo
Found indicators: package.json, .vscode/

Recommended templates:
- Node.gitignore
- VisualStudioCode.gitignore (for global)

Proceed with these templates? [Y/n/edit]

Allow user to:

•Confirm (Y)
•Cancel (n)
•Edit the list (add/remove templates)

Step 4: Fetch and Merge

Use the merge-gitignore.sh script located at ${CLAUDE_PLUGIN_ROOT}/scripts/merge-gitignore.sh:

bash

"${CLAUDE_PLUGIN_ROOT}/scripts/merge-gitignore.sh" Node Python macOS

Merge Order (later entries have higher priority in gitignore):

•Templates section - github/gitignore templates with START/END markers (easiest to replace/update)
•Local files section - Project-specific ignores
•Overrides section - Custom overrides with highest priority (last wins in gitignore)

Step 5: Handle EOL Conflicts

If the script detects mixed line endings:

code

⚠️ EOL inconsistency detected:
  - Node.gitignore: LF
  - VisualStudio.gitignore: CRLF
  - Existing .gitignore: LF

Choose unified format:
1. LF (Unix/macOS) - recommended
2. CRLF (Windows)
3. Keep as-is (no conversion)

Wait for user confirmation before proceeding.

Step 6: Show Diff Preview

If target .gitignore already exists, show a diff:

diff

📄 Will write to: /path/to/repo/.gitignore

--- Existing content
+++ Merged content

@@ -1,5 +1,60 @@
+# ╔═══════════════════════════════════════════════════════════════════════╗
+# ║ START - github/gitignore templates                                    ║
+# ╚═══════════════════════════════════════════════════════════════════════╝
+
+# --------------------------------------------
+# Source: Node.gitignore
+# --------------------------------------------
+node_modules/
+...
+
+# ╔═══════════════════════════════════════════════════════════════════════╗
+# ║ END - github/gitignore templates                                      ║
+# ╚═══════════════════════════════════════════════════════════════════════╝
+
+# ============================================
+# Local files (project-specific ignores)
+# ============================================
+
+# ============================================
+# Overrides (highest priority - last wins)
+# ============================================
+
 # User custom rules
 my-custom-file.txt

Confirm write? [Y/n]

Step 7: Write File

After user confirms, write the file and report success:

code

✅ Created /path/to/repo/.gitignore (150 lines, 3 templates merged)

Important Notes

Always Recommend *.local Pattern

At the end of every gitignore generation, suggest:

code

💡 Tip: Consider adding these patterns for local configuration files:
   *.local
   *.local.*

These patterns prevent accidentally committing local overrides.

Gitignore Syntax Reminders

When discussing or modifying gitignore:

•Negation: The exclamation mark prefix negates a pattern, re-including previously excluded files. Order is important: the negation must come after the exclusion. Example: !important.log re-includes important.log.
•Order matters: Later patterns override earlier ones.
•Comments: Lines starting with # are comments.
•Directory: Trailing / matches only directories (e.g., build/).
•Wildcards: * matches anything except /, ** matches everything including /.

Source Attribution & Structure

Templates section must be wrapped with START/END markers:

gitignore

# ╔═══════════════════════════════════════════════════════════════════════╗
# ║                    github/gitignore templates                         ║
# ║           https://github.com/github/gitignore                         ║
# ╠═══════════════════════════════════════════════════════════════════════╣
# ║ START - Do not edit this section manually                             ║
# ╚═══════════════════════════════════════════════════════════════════════╝

# --------------------------------------------
# Source: Node.gitignore
# --------------------------------------------
node_modules/
...

# ╔═══════════════════════════════════════════════════════════════════════╗
# ║ END - github/gitignore templates                                      ║
# ╚═══════════════════════════════════════════════════════════════════════╝

This makes it easy to:

•Identify template content for updates (replace between START/END)
•Understand where each rule comes from
•Avoid accidental edits to generated content

Preserve User Content

If merging with an existing .gitignore, preserve user-added content in the appropriate section:

gitignore

# ╔═══════════════════════════════════════════════════════════════════════╗
# ║ START - github/gitignore templates                                    ║
# ╚═══════════════════════════════════════════════════════════════════════╝

# --------------------------------------------
# Source: Node.gitignore
# --------------------------------------------
node_modules/
...

# ╔═══════════════════════════════════════════════════════════════════════╗
# ║ END - github/gitignore templates                                      ║
# ╚═══════════════════════════════════════════════════════════════════════╝

# ============================================
# Local files (project-specific ignores)
# ============================================

secret-folder/
local-config.json

# ============================================
# Overrides (highest priority - last wins)
# ============================================

# User custom rules (preserved from original)
my-custom-rule.txt
!important.log

Reference Files

•examples.md - Detailed workflow examples for various scenarios

Script Reference

The merge-gitignore.sh script handles:

•Fetching templates from github/gitignore via raw.githubusercontent.com
•Detecting and reporting EOL inconsistencies
•Concatenating templates with source attribution
•Outputting to stdout for preview/confirmation workflow

Usage:

bash

# Fetch and merge templates
"${CLAUDE_PLUGIN_ROOT}/scripts/merge-gitignore.sh" <template1> [template2] ...

# Templates can be:
# - Top-level: Node, Python, Rust, Go, etc.
# - Global: Global/macOS, Global/VisualStudioCode, etc.

Exit Codes:

Code	Meaning
0	Success
1	Network error (failed to fetch)
2	EOL conflict detected (info in stderr)