Git: Viewing Git Logs and Tracking History

# View Full History
git log

# Output Format：
# commit a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0
# Author: Zhang San <zhangsan@example.com>
# Date:   Mon Jan 1 10:00:00 2026 +0800
#
#     feat: Add User Login Functionality
#
# commit d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0u1v2
# Author: Li Si <lisi@example.com>
# Date:   Sun Dec 31 15:30:00 2025 +0800
#
#     fix: Fix the login authentication error

# One commit per line
git log --oneline

# Output：
# a1b2c3d feat: Add User Login Functionality
# d4e5f6g fix: Fix the login authentication error
# h7i8j9k docs: UpdateREADME
# l0m1n2o Initial commit

# Abbreviated form
git log --oneline --decorate

# Output：
# a1b2c3d (HEAD -> main) feat: Add User Login Functionality
# d4e5f6g (origin/main) fix: Fix the login authentication error

# Show Recent3Next Submission
git log -3

# Or
git log -n 3

# Simplified Mode: Show Recent 5
git log --oneline -5

# Output：
# a1b2c3d feat: Add User Login Functionality
# d4e5f6g fix: Fix the login authentication error
# h7i8j9k docs: UpdateREADME
# k9l0m1n style: Code Formatting
# n2o3p4q refactor: Optimize Query Logic

# Display File Change Statistics
git log --stat

# Output：
# commit a1b2c3d4e5f6...
# Author: Zhang San <zhangsan@example.com>
# Date:   Mon Jan 1 10:00:00 2026 +0800
#
#     feat: Add User Login Functionality
#
#  src/auth/login.js | 25 +++++++++++++++++++++++++
#  src/auth/index.js  |  3 ++-
#  2 files changed, 26 insertions(+), 2 deletions(-)

# Show the full diff for each commit
git log -p

# Show the differences from the most recent commit
git log -1 -p

# Output：
# commit a1b2c3d4e5f6...
# Author: Zhang San <zhangsan@example.com>
# Date:   Mon Jan 1 10:00:00 2026 +0800
#
#     feat: Add User Login Functionality
#
# diff --git a/src/auth/login.js b/src/auth/login.js
# new file mode 100644
# index 0000000..abc1234
# --- /dev/null
# +++ b/src/auth/login.js
# @@ -0,0 +1,25 @@
# +function login(username, password) {
# +  // Validation Logic
# +}

# Use a preset format
git log --pretty=oneline
git log --pretty=short
git log --pretty=full
git log --pretty=fuller

# Custom Format
git log --pretty=format:"%h - %an, %ar : %s"

# Output：
# a1b2c3d - Zhang San, 2 hours ago : feat: Add User Login Functionality
# d4e5f6g - Li Si, 1 day ago : fix: Fix the login authentication error

# A more detailed format
git log --pretty=format:"%C(yellow)%h%C(reset) - %C(green)%an%C(reset), %C(blue)%ar%C(reset) : %s"

# Table Format
git log --pretty=format:"%h | %an | %ad | %s" --date=short

# Output：
# a1b2c3d | Zhang San | 2026-01-01 | feat: Add User Login Functionality
# d4e5f6g | Li Si | 2025-12-31 | fix: Fix the login authentication error

# After the specified date
git log --since="2026-01-01"

# Before the specified date
git log --until="2026-01-31"

# Relative Time
git log --since="1 week ago"
git log --since="2 months ago"
git log --after="yesterday"

# Time Range
git log --since="2026-01-01" --until="2026-01-31"

# Combined Use
git log --oneline --since="1 week ago" --until="yesterday"

# By Author Name
git log --author="Zhang San"

# By author's email address
git log --author="zhangsan@example.com"

# Fuzzy Matching
git log --author="Zhang"

# Combined Filtration
git log --author="Zhang San" --since="1 week ago"

# Search and Submit Information
git log --grep="fix"

# Multiple conditions（or relationship）
git log --grep="fix" --grep="feat"

# Regular Expressions
git log --grep="feat\|fix"

# Ignore case
git log --grep="FIX" -i

# Combined Filtration
git log --author="Zhang San" --grep="feat"

# View the history of a specific file
git log -- README.md

# View Multiple Files
git log -- file1.js file2.js

# View Catalog History
git log -- src/auth/

# Show File Differences
git log -p -- README.md

# Display File Change Statistics
git log --stat -- README.md

# Show only commits that modified this file
git log --oneline -- README.md

# Output：
# a1b2c3d docs: UpdateREADME
# h7i8j9k docs: Add Installation Instructions
# l0m1n2o Initial commit

# View the history between two commits
git log a1b2c3d..d4e5f6g

# View the history following a specific commit
git log a1b2c3d..

# View the history leading up to a specific commit
git log ..d4e5f6g

# View Branch Differences
git log main..feature

# View the differences between the two branches
git log main...feature

# Start the binary search
git bisect start

# Mark the current commit as problematic
git bisect bad

# Mark a commit as normal
git bisect good v1.0.0

# GitIt will automatically switch to the middle submission
# Marked as good or bad after testing
git bisect good
# Or
git bisect bad

# After finding and submitting a bug
# a1b2c3d is the first bad commit

# End Binary Search
git bisect reset

# View the complete change history for the file
git log --follow -p -- filename

# View the revision history for each line of the file
git blame filename

# Output：
# a1b2c3d (Zhang San 2026-01-01 10:00:00  1) function login() {
# d4e5f6g (Li Si 2025-12-31 15:30:00  2)   // Validation Logic
# h7i8j9k (Zhang San 2025-12-30 09:00:00  3) }

# View the history for a specific row
git log -L 10,20:filename

# View Function History
git log -L :functionName:filename

# ViewHEADMovement History
git reflog

# Output：
# a1b2c3d HEAD@{0}: commit: feat: Add Feature
# d4e5f6g HEAD@{1}: checkout: moving from feature to main
# h7i8j9k HEAD@{2}: commit: Feature work
# l0m1n2o HEAD@{3}: checkout: moving from main to feature

# View the history of a specific citation
git reflog show HEAD
git reflog show main

# Restore to the previous state
git reset HEAD@{5}