git-lock

Disable the ability to commit changes of a local file

$ git lock [path/to/file]

git-lock subcommand [options] [arguments]

Subcommands:
    lock path...
    unlock path...
    status [path...]
    break path...

lock path...
    Acquires an exclusive lock on the specified file(s). If a file is already locked by another user, the command will fail unless overridden.

unlock path...
    Releases the lock(s) on the specified file(s). Only the lock owner can unlock a file by default.

status [path...]
    Displays the current lock status. If path is provided, shows status for specific files; otherwise, lists all currently locked files in the repository.

break path...
    Forcibly releases a lock on the specified file(s), regardless of who owns it. This command typically requires elevated permissions or administrator rights.

--dry-run
    For 'lock' and 'unlock', show what would happen without actually modifying lock status.

--all
    With 'status', show all files that are currently locked in the repository.

--verbose
    Produce more verbose output, showing details like lock owner, timestamp, etc.

The git-lock command provides a mechanism for exclusive file locking within a Git repository. Unlike Git's distributed model which excels at merging textual changes, certain files, particularly binary assets or complex project files, do not merge well. git-lock addresses this by allowing a developer to acquire an exclusive lock on a file, preventing other team members from modifying or pushing changes to that specific file until the lock is released. This helps to avoid conflicts and ensures data integrity for non-mergeable assets. The locking mechanism typically relies on a centralized or shared state, which could be managed by a dedicated server, a shared Git reference, or a convention within the repository itself. Users can lock a file, view current locks, and unlock files, including the ability to forcefully break a lock in emergency situations. It acts as an extension to Git, enabling workflows that require strict serialization of changes on particular files.

It is crucial to understand that git-lock is not a standard, built-in Git command. It typically represents an external utility, script, or a feature provided by a specific Git extension (e.g., some forms of Git LFS for binary files). Its implementation requires a centralized or shared mechanism to store lock information, which goes against Git's inherently distributed nature. This means it may require server-side hooks or a dedicated daemon. Locks only prevent others from pushing conflicting changes; they do not prevent local modifications by another user who hasn't pulled the lock information. Stale locks can occur if a user's client crashes or they forget to unlock files, potentially blocking workflow. Force-breaking locks should be used with caution.

The actual implementation of git-lock varies widely. Common approaches include storing lock information in a dedicated branch, a shared file within the repository (e.g., .git/locks or a custom file), a centralized database, or leveraging Git server-side hooks (e.g., pre-receive) to enforce lock rules during push operations.

For effective use, git-lock often integrates with Git hooks. A 'pre-commit' hook might warn users about trying to commit a locked file, and a 'pre-push' hook on the server can reject pushes that modify locked files owned by others.

The concept of exclusive file locking predates Git, being a common feature in centralized version control systems like SVN or Perforce to prevent concurrent modifications on files that are difficult to merge. With Git's distributed and merge-centric design, explicit locking became less critical for text-based files. However, the challenge of managing binary assets or non-mergeable project files persisted. This led to the development of external tools and conventions to provide a "locking" capability for Git workflows. While Git LFS (Large File Storage) introduced a standard mechanism for locking LFS-tracked files, a general "git-lock" command often refers to custom scripts or third-party extensions designed to extend locking to any file type or to provide a broader locking strategy, addressing specific project needs where merge conflicts on certain files are highly disruptive.

git-lfs-lock(1), git-lfs-unlock(1), git-lfs-locks(1), git-status(1)