Git 進階使用

使用 rev-parse

# Getting the top-level directory
git rev-parse --show-toplevel

# Find your way home
git rev-parse --show-cdup

## Current location
# 判斷是否在專案目錄 <git-repo>/.git 底下 
git rev-parse --is-inside-git-dir
# 判斷是否在專案目錄 <git-repo> 底下 (不包含 .git 目錄下)
git rev-parse --is-inside-work-tree

合併發生衝突

• How to Fix Merge Conflicts in Git

Git credential cache

This command caches credentials for use by future Git programs. The stored credentials are kept in memory of the cache-daemon process (instead of being written to a file) and are forgotten after a configurable timeout.

git config credential.helper cache
git config credential.helper 'cache --timeout=3600'

Shallow Clone (淺複製)

何時使用 shallow clone:

• You don’t need the full commit history
• You want faster setup for CI/CD pipelines
• You’re working with large repositories

# Shallow clone
# Limit the clone to 100 commits before the current repository HEAD.
git clone --depth=100 <Repository_URL>

# Shallow Cloning Only a Single Branch
git clone --depth 100 <repository_URL> --single-branch --branch=<branch-name>

# Clone commits since a specific date
git clone --shallow-since="2024-01-01" <repository_URL>

# Skip large file downloads
git clone --filter=blob:none <Repository_URL>

# Unshallow a shallow clone
git fetch --unshallow

Common issues with shallow clones

• git merge-base
• git rebase
• git bisect

Fix: Run git fetch --unshallow or avoid shallow clone in those contexts.

Efficient Fetching Strategies for Shallow Clones

# Fetch with Limited Depth
git fetch origin --depth=5

# Fetch by Date
git fetch origin --shallow-since="2024-01-01"

# Fetch by Excluding Old Commits
git fetch origin --shallow-exclude=a1b2c3d

# Fetch Specific Branches/Tags
git fetch origin main --depth=10
git fetch origin refs/tags/v2.1.0 --depth=1