Git: Gitのクローン作成とセキュリティ更新に関する詳細ガイド

# Get updates from all remote repositories
git fetch

# Output：
# remote: Enumerating objects: 8, done.
# remote: Counting objects: 100% (8/8), done.
# remote: Compressing objects: 100% (5/5), done.
# remote: Total 5 (delta 3), reused 0 (delta 0), pack-reused 0
# Unpacking objects: 100% (5/5), 1.23 KiB | 1.23 MiB/s, done.
# From https://github.com/user/repo
#    a1b2c3d..d4e5f6g  main        -> origin/main
#  * [new branch]      feature     -> origin/feature
#  * [new tag]         v1.0.0      -> v1.0.0

# GetoriginUpdates
git fetch origin

# GetupstreamUpdates
git fetch upstream

# Get all remote repositories
git fetch --all

# Output：
# Fetching origin
# Fetching upstream
# Fetching backup

# Get a Specific Branch
git fetch origin main

# Retrieve Multiple Branches
git fetch origin main develop

# Fetch a remote branch with a different name locally
git fetch origin main:local-main

# Retrieve and Create a Local Branch
git fetch origin feature:feature

# Get Updates
git fetch origin

# View Remote Branches
git branch -r

# Output：
#   origin/HEAD -> origin/main
#   origin/main
#   origin/develop
#   origin/feature

# View All Branches
git branch -a

# Output：
# * main
#   develop
#   remotes/origin/HEAD -> origin/main
#   remotes/origin/main
#   remotes/origin/develop
#   remotes/origin/feature

# View the latest commit on a remote branch
git log origin/main

# Output：
# commit d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0u1v2
# Author: Zhang San <zhangsan@example.com>
# Date:   Mon Jan 1 10:00:00 2026 +0800
#
#     feat: Add a New Feature

# View new commits on the remote repository（Not available locally）
git log main..origin/main

# Output：
# d4e5f6g (origin/main) feat: Add a New Feature
# h7i8j9k fix: FixBug

# View commits that exist locally but not remotely
git log origin/main..main

# View Bidirectional Differences
git log main...origin/main

# Compare the differences between local and remote
git diff main origin/main

# View Difference Statistics
git diff --stat main origin/main

# Output：
#  src/auth.js  | 10 ++++++++++
#  src/user.js  |  5 ++---
#  2 files changed, 12 insertions(+), 3 deletions(-)

# View the list of modified files
git diff --name-only main origin/main

# Output：
# src/auth.js
# src/user.js

# View detailed file status
git diff --name-status main origin/main

# Output：
# M  src/auth.js
# M  src/user.js

# Get Updates
git fetch origin

# View Updates
git log main..origin/main

# Merge Remote Updates
git merge origin/main

# Output：
# Updating a1b2c3d..d4e5f6g
# Fast-forward
#  src/auth.js | 10 ++++++++++
#  1 file changed, 10 insertions(+)

# Get Updates
git fetch origin

# UsagerebaseMerge
git rebase origin/main

# Output：
# First, rewinding head to replay your work on top of it...
# Fast-forwarded main to d4e5f6g.

# If there is a conflict
# CONFLICT (content): Merge conflict in file.js
# After Resolving the Conflict
git add file.js
git rebase --continue

# Get Updates
git fetch origin

# View new commits on the remote repository
git log main..origin/main --oneline

# Output：
# d4e5f6g feat: Add FeatureC
# h7i8j9k fix: FixBug
# k9l0m1n feat: Add FeatureB

# Merge only a specific commit
git cherry-pick h7i8j9k

# Or merge multiple commits
git cherry-pick k9l0m1n d4e5f6g

# Get Updates（Including tags）
git fetch origin

# Output：
#  * [new tag]         v1.0.0      -> v1.0.0
#  * [new tag]         v1.1.0      -> v1.1.0

# View All Tags
git tag

# Output：
# v1.0.0
# v1.1.0

# View tag details
git show v1.0.0

# Get a specific tag
git fetch origin refs/tags/v1.0.0:refs/tags/v1.0.0

# Get all tags
git fetch --tags

# Delete Local Tags（Remotely Deleted）
git fetch --prune-tags

# Or
git fetch -p --prune-tags

# Clean up expired remote branch references
git fetch -p

# Output：
# From https://github.com/user/repo
#  x [deleted]         (none)     -> origin/old-feature

# Delete Expired Tags
git fetch --prune-tags

# Simulated Acquisition
git fetch --dry-run

# Detailed Output
git fetch --verbose

# Gain Insight（Shallow Cloning）
git fetch --depth=1

# Get a single branch
git fetch --single-branch

# View the branches that need to be cleaned up
git remote prune origin --dry-run

# Output：
# * origin/deleted-branch would be pruned

# Perform Cleanup
git remote prune origin

# Or usefetch -p
git fetch -p

# Output：
# From https://github.com/user/repo
#  x [deleted]         (none)     -> origin/deleted-branch

# Scene1：Check for Updates Before Starting Work
git fetch origin
git log main..origin/main --oneline

# Output：
# d4e5f6g feat: New Features
# h7i8j9k fix: BugFix

# View Specific Changes
git diff main origin/main

# Decide whether to merge
git merge origin/main

# Scene2：There is unsubmitted work，Get it first, then decide
git fetch origin
git status

# Output：
# On branch main
# Your branch is behind 'origin/main' by 2 commits.

# View Updates
git log HEAD..origin/main

# Save the current work
git stash

# Merge Updates
git merge origin/main

# Return to Work
git stash pop

# Scene3：ForkWorkflow
git fetch upstream
git log main..upstream/main
git merge upstream/main
git push origin main

#!/bin/bash
# sync.sh - Regularly Synchronize Remote Updates

# Get all remote updates
git fetch --all

# Check the status of each branch
for branch in $(git branch --format='%(refname:short)'); do
    upstream=$(git rev-parse --abbrev-ref $branch@{upstream} 2>/dev/null)
    if [ -n "$upstream" ]; then
        behind=$(git rev-list --count $branch..$upstream 2>/dev/null)
        ahead=$(git rev-list --count $upstream..$branch 2>/dev/null)
        if [ "$behind" -gt 0 ] || [ "$ahead" -gt 0 ]; then
            echo "$branch: behind $behind, ahead $ahead"
        fi
    fi
done

# Ask if it's synced
read -p "Sync main branch? (y/n) " -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]; then
    git checkout main
    git merge origin/main
fi