git(1) — The Stupid Content Tracker

Reference, not a lesson — condensed from the official Git manual page git(1). The numbered course pages teach the model; this records what the manual says. Checked against Git 2.48.1: nothing on this page depends on a newer release.

The primary manual page for the Git suite (git). Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.

High-level tutorials and references:

Synopsis

git [-v | --version] [-h | --help] [-C <path>] [-c <name>=<value>]
    [--config-env=<name>=<envvar>] [--exec-path[=<path>]] [--html-path]
    [--man-path] [--info-path] [-p | --paginate | -P | --no-pager]
    [--no-replace-objects] [--no-lazy-fetch] [--no-optional-locks]
    [--no-advice] [--bare] [--git-dir=<path>] [--work-tree=<path>]
    [--namespace=<name>] [--attr-source=<tree-ish>] <command> [<args>]

Options & Flags

  • -v, --version: Print the Git suite version and exit.
  • -h, --help: Print synopsis and common commands. If -a or --all is specified, list all available commands. If a command name is given, open its manual page.
  • -C <path>: Run as if Git was started in <path> instead of current working directory. Multiple -C options evaluate sequentially.
  • -c <name>=<value>: Pass a configuration parameter overriding configuration file settings. Omitting =value sets the boolean to true. Setting name= sets it to false/empty.
  • --config-env=<name>=<envvar>: Pass configuration variable populated from the specified environment variable (avoids exposing sensitive credentials in process listings).
  • --exec-path[=<path>]: Path to Git core executable binaries. Unset parameter prints current default path and exits.
  • --html-path / --man-path / --info-path: Print paths to Git’s HTML, man, or info documentation files and exit.
  • -p, --paginate: Pipe output into less (or $PAGER) if stdout is a TTY.
  • -P, --no-pager: Do not pipe Git output into a pager.
  • --git-dir=<path>: Set path to repository (.git directory). Disables automatic top-level repository discovery.
  • --work-tree=<path>: Set path to the root of the working tree.
  • --namespace=<name>: Set the Git namespace (equivalent to GIT_NAMESPACE).
  • --bare: Treat repository as a bare repository (sets GIT_DIR to current directory if not already set).
  • --no-replace-objects: Ignore replacement refs (equivalent to GIT_NO_REPLACE_OBJECTS).
  • --no-lazy-fetch: Disable on-demand object fetching from promisor remotes in partial clones (GIT_NO_LAZY_FETCH=1).
  • --no-optional-locks: Skip optional background operations requiring file locks (GIT_OPTIONAL_LOCKS=0).
  • --no-advice: Disable advice/hint messages printed by commands.
  • --literal-pathspecs: Treat pathspecs literally without globbing (GIT_LITERAL_PATHSPECS=1).
  • --glob-pathspecs / --noglob-pathspecs: Force enabling or disabling wildcards/globbing on pathspecs.
  • --icase-pathspecs: Treat pathspecs as case-insensitive (GIT_ICASE_PATHSPECS=1).
  • --list-cmds=<group>[,<group>...]: List internal commands by group (e.g., builtins, main, others, alias, config).
  • --attr-source=<tree-ish>: Read .gitattributes from <tree-ish> instead of the working tree.

Command Classifications

Git commands are divided into High-level (Porcelain) commands designed for user workflows and Low-level (Plumbing) commands designed for scripting and tool creation.

High-Level Commands (Porcelain)

Main Porcelain Commands

  • add: Add file contents to the index (staging area).
  • am: Apply a series of patches from a mailbox.
  • archive: Create an archive of files from a named tree.
  • bisect: Binary search to find the commit that introduced a bug.
  • branch: List, create, or delete branches.
  • bundle: Move objects and refs by single-file archive.
  • checkout: Switch branches or restore working tree files.
  • citool: Graphical alternative to git-commit.
  • clean: Remove untracked files from working tree.
  • clone: Clone a repository into a new directory.
  • commit: Record changes to the repository.
  • describe: Give an object a human-readable name based on closest tag.
  • diff: Show changes between commits, commit and working tree, etc.
  • fetch: Download objects and refs from another repository.
  • format-patch: Prepare patches for e-mail submission.
  • gc: Cleanup unnecessary files and optimize local repository.
  • grep: Print lines matching a pattern.
  • gui: Portable graphical interface to Git.
  • init: Create an empty Git repository or reinitialize an existing one.
  • log: Show commit logs.
  • maintenance: Run tasks to optimize Git repository data.
  • merge: Join two or more development histories together.
  • mv: Move or rename a file, directory, or symlink.
  • notes: Add or inspect object notes.
  • pull: Fetch from and integrate with another repository/branch.
  • push: Update remote refs along with associated objects.
  • range-diff: Compare two commit ranges.
  • rebase: Reapply commits on top of another base tip.
  • reset: Reset current HEAD to a specified state (modifies branch tip/index/working tree).
  • restore: Restore working tree files from index or commit without updating branch.
  • revert: Revert existing commits by creating new inverse commits.
  • rm: Remove files from working tree and index.
  • scalar: Management tool for large Git repositories.
  • shortlog: Summarize git log output.
  • show: Show various types of objects (commits, tags, trees, blobs).
  • sparse-checkout: Reduce working tree to a subset of tracked files.
  • stash: Stash changes in a dirty working directory.
  • status: Show working tree status.
  • submodule: Initialize, update, or inspect submodules.
  • switch: Switch branches cleanly.
  • tag: Create, list, delete, or verify GPG-signed tags.
  • worktree: Manage multiple working trees linked to one repository.
  • gitk: Git repository browser GUI.

Ancillary Commands

  • Manipulators:
    • config: Get and set repository or global options.
    • fast-export: Export repository history.
    • fast-import: Backend for fast Git data importers.
    • filter-branch: Rewrite branches.
    • mergetool: Run merge conflict resolution tools.
    • pack-refs: Pack heads and tags for efficient repository access.
    • prune: Prune unreachable objects.
    • reflog: Manage reflog information.
    • refs: Low-level access to refs.
    • remote: Manage set of tracked repositories.
    • repack: Pack unpacked objects into packfiles.
    • replace: Create, list, or delete refs to replace objects.
  • Interrogators:
    • annotate / blame: Show commit and author information per file line.
    • bugreport: Collect information to file a bug report.
    • count-objects: Count unpacked objects and disk usage.
    • diagnose: Generate a zip archive of diagnostic information.
    • difftool: Show changes using external diff tools.
    • fsck: Verify connectivity and validity of repository objects.
    • help: Display help information.
    • instaweb: Browse repository in web browser via gitweb.
    • merge-tree: Perform merge without touching index/worktree.
    • rerere: Reuse recorded resolution of conflicted merges.
    • show-branch: Show branches and their commits.
    • verify-commit / verify-tag: Check GPG signatures.
    • version: Display version information.
    • whatchanged: Show commit log with diffs.
    • gitweb: Git web frontend interface.

Interacting with Foreign Systems

  • archimport: Import GNU Arch repository.
  • cvsexportcommit: Export single commit to CVS.
  • cvsimport: Import CVS repository.
  • cvsserver: CVS server emulator.
  • imap-send: Send patch collection to IMAP folder.
  • p4: Import/submit to Perforce repositories.
  • quiltimport: Apply quilt patchset onto branch.
  • request-pull: Generate summary of pending changes.
  • send-email: Send patches as emails.
  • svn: Bidirectional operation between Subversion and Git.

Low-Level Commands (Plumbing)

Manipulation Commands

  • apply: Apply patch to files or index.
  • checkout-index: Copy files from index to working tree.
  • commit-graph: Write/verify commit-graph files.
  • commit-tree: Create a new commit object.
  • hash-object: Compute SHA object ID and optionally create object in object store.
  • index-pack: Build pack index file for packed archive.
  • merge-file: Run three-way file merge.
  • merge-index: Run merge for files needing merging.
  • mktag: Create tag object with extra validation.
  • mktree: Build tree object from ls-tree formatted text.
  • multi-pack-index: Write and verify multi-pack-indexes.
  • pack-objects: Create packed archive of objects.
  • prune-packed: Remove extra loose objects present in packs.
  • read-tree: Read tree information into index.
  • replay: Replay commits on new base.
  • symbolic-ref: Read, modify, delete symbolic refs.
  • unpack-objects: Unpack objects from pack archive.
  • update-index: Register working tree contents to index.
  • update-ref: Safely update object name stored in a ref.
  • write-tree: Create tree object from current index.

Interrogation Commands

  • cat-file: Provide contents or details of objects.
  • cherry: Find commits not yet applied upstream.
  • diff-files / diff-index / diff-tree: Low-level diffing utilities.
  • for-each-ref: Output formatted details on refs.
  • for-each-repo: Run command across list of repositories.
  • ls-files: List files in index and working tree.
  • ls-remote: List references in remote repository.
  • ls-tree: List contents of a tree object.
  • merge-base: Find common ancestor for merges.
  • name-rev: Find symbolic names for given revs.
  • rev-list: List commits in reverse chronological order.
  • rev-parse: Pick out and parse parameters/object specs.
  • show-ref: List references in local repository.
  • var: Show Git logical variables.
  • verify-pack: Validate packed Git archive files.

Syncing Repositories & Helpers

  • daemon: Simple server for Git repositories.
  • fetch-pack: Receive missing objects from another repo.
  • http-backend: Server-side HTTP transport implementation.
  • send-pack: Push objects over Git protocol.
  • update-server-info: Update auxiliary info file for dumb servers.
  • Server transfer helpers: http-fetch, http-push, receive-pack, upload-pack, upload-archive, shell.

Internal Helper Commands

  • check-attr: Display gitattributes information.
  • check-ignore: Debug .gitignore rules.
  • check-mailmap: Show canonical names/emails via mailmap.
  • check-ref-format: Validate reference name formats.
  • credential / credential-cache / credential-store: Credential helpers.
  • hook: Execute Git hooks.
  • interpret-trailers: Add or parse structured commit trailers.
  • stripspace: Clean up whitespace.

Configuration Hierarchy & Files

Git uses INI-formatted text files with sections and key-value parameters:

[core]
    filemode = false
[user]
    name = "Tony"
    email = "tony@example.com"

Configuration Resolution Order (Precedence)

  1. Command-line Level: Passed via -c <name>=<value> or --config-env.
  2. Worktree Level: $GIT_DIR/config.worktree (if extensions.worktreeConfig is enabled).
  3. Local (Repository) Level: $GIT_DIR/config.
  4. Global (User) Level: $HOME/.gitconfig or $XDG_CONFIG_HOME/git/config (overridden by GIT_CONFIG_GLOBAL).
  5. System Level: $(prefix)/etc/gitconfig or /etc/gitconfig (overridden by GIT_CONFIG_SYSTEM or skipped via GIT_CONFIG_NOSYSTEM=true).

Repository Layout & Key File Locations

Detailed in gitrepository-layout(5). By default, repository internals reside under .git/ (or $GIT_DIR):

  • $GIT_DIR/index: Staging area cache file.
  • $GIT_DIR/objects/: Content-addressed object database (blobs, trees, commits, tags).
  • $GIT_DIR/refs/: Pointer files (refs/heads/, refs/tags/, refs/remotes/).
  • $GIT_DIR/HEAD: Reference file pointing to active branch or detached commit SHA.
  • $GIT_DIR/config: Per-repository configuration file.
  • $GIT_DIR/hooks/: Execution scripts triggered by Git actions.

Identifier Syntax & Default Values

Terminology Identifiers

  • <object>: Object name (40-char SHA or ref) for any Git object type.
  • <blob> / <tree> / <commit> / <tag>: Object names for specific types.
  • <tree-ish>: Evaluates to a tree object (accepts tree, commit, or tag dereferencing to a tree).
  • <commit-ish>: Evaluates to a commit object (accepts commit or tag dereferencing to a commit).
  • HEAD: Points to current branch tip or active commit.

Key Default Settings

  • Object Hash Format: sha1 (configurable via GIT_DEFAULT_HASH or --object-format).
  • Ref Storage Backend: files (configurable via GIT_DEFAULT_REF_FORMAT or reftable).
  • Index Version: Version 2 or 3.
  • GIT_PROGRESS_DELAY: 1 second.
  • GIT_OPTIONAL_LOCKS: 1 (enabled).
  • GIT_REF_PARANOIA: 1 (enabled).

Environment Variables

Repository Structure & Paths

  • GIT_DIR: Path to .git directory.
  • GIT_WORK_TREE: Path to root of working tree.
  • GIT_INDEX_FILE: Alternate index location (default $GIT_DIR/index).
  • GIT_INDEX_VERSION: Specifies index format version on write.
  • GIT_OBJECT_DIRECTORY: Alternate directory for primary object store (default $GIT_DIR/objects).
  • GIT_ALTERNATE_OBJECT_DIRECTORIES: Colon-separated (semicolon on Windows) list of read-only shared object stores.
  • GIT_CEILING_DIRECTORIES: List of absolute paths Git should not traverse up when searching for a repository.
  • GIT_DISCOVERY_ACROSS_FILESYSTEM: Boolean flag allowing Git to cross filesystem boundaries when discovering .git.
  • GIT_COMMON_DIR: Common directory for multi-worktree repository objects/refs.
  • GIT_NAMESPACE: Sets Git namespace.
  • GIT_DEFAULT_HASH: Default object hashing algorithm (sha1 or sha256).
  • GIT_DEFAULT_REF_FORMAT: Default reference backend format (files or reftable).

Commit & Author Identity

  • GIT_AUTHOR_NAME / GIT_AUTHOR_EMAIL / GIT_AUTHOR_DATE: Author metadata override.
  • GIT_COMMITTER_NAME / GIT_COMMITTER_EMAIL / GIT_COMMITTER_DATE: Committer metadata override.
  • EMAIL: Fallback user email address.

Execution, Pagers & Editors

  • GIT_PAGER: Pager binary override (overrides PAGER).
  • GIT_EDITOR / GIT_SEQUENCE_EDITOR: Text editor binary overrides (for commit messages and interactive rebase).
  • GIT_SSH / GIT_SSH_COMMAND / GIT_SSH_VARIANT: Custom SSH binary or invocation command.
  • GIT_SSL_NO_VERIFY: Disables HTTPS SSL certificate verification when true.
  • GIT_ASKPASS: Binary executable for non-interactive credential prompting.
  • GIT_TERMINAL_PROMPT: Set to 0/false to disable terminal password prompts.

Diffs & Merges

  • GIT_DIFF_OPTS: Override default diff context options.
  • GIT_EXTERNAL_DIFF: Invokes external command for diff evaluation.
  • GIT_EXTERNAL_DIFF_TRUST_EXIT_CODE: If true, respects exit code 0 (equal) vs 1 (different).
  • GIT_MERGE_VERBOSITY: Numeric controls for merge log output details.

Tracing & Debugging

  • GIT_TRACE: General trace messages (stdout, file descriptor, or log path).
  • GIT_TRACE_FSMONITOR: Trace filesystem monitor calls.
  • GIT_TRACE_PACK_ACCESS: Log pack accesses and offsets.
  • GIT_TRACE_PACKET / GIT_TRACE_PACKFILE: Network wire packet and packfile logging.
  • GIT_TRACE_PERFORMANCE: Trace command timing and performance metrics.
  • GIT_TRACE_SETUP: Log internal repository setup details.
  • GIT_TRACE_CURL: Verbose transport HTTP/cURL log.
  • GIT_TRACE2 / GIT_TRACE2_EVENT / GIT_TRACE2_PERF: Structured Trace2 logging engine.
  • GIT_TRACE_REDACT: Set to false to prevent redaction of authorization headers and cookies in trace logs.

Behavior & Safety Controls

  • GIT_NO_REPLACE_OBJECTS: Disable replace refs.
  • GIT_LITERAL_PATHSPECS / GIT_GLOB_PATHSPECS / GIT_ICASE_PATHSPECS: Pathspec behavior toggles.
  • GIT_NO_LAZY_FETCH: Prevent automatic object fetching in partial clones.
  • GIT_REF_PARANOIA: Set to 0 to ignore broken refs during traversal.
  • GIT_OPTIONAL_LOCKS: Set to 0 to prevent background tasks from locking index files.

See Also