git/reset

• git reset

  • Overview

    • git reset is a command that updates the repository state by moving the current branch pointer and optionally modifying the working directory and staging area
    • Primary purpose is to undo changes or move the branch pointer to a different commit

  • Core Components

    • Command Structure

      • Basic syntax: git reset [options] [commit]
      • Common options:
        • --soft: Only moves HEAD and branch pointer
        • --mixed: Default mode; moves HEAD and updates staging area
        • --hard: Moves HEAD, updates staging area, and working directory

    • Reset Modes

      • Soft Reset git/reset/--soft

        • Only moves the branch pointer
        • Keeps all changes in staging area
        • Example: git reset --soft HEAD~1
        • Use case: Undo last commit while keeping changes staged

      • Mixed Reset git/reset/--mixed

        • Default mode if no option specified
        • Moves branch pointer and unstages changes
        • Example: git reset HEAD~1
        • Use case: Undo commit and staging, keep changes in working directory

      • Hard Reset (--hard) git/reset/--hard

        • Most aggressive mode
        • Moves branch pointer and discards all changes
        • Example: git reset --hard HEAD~1
        • Use case: Completely discard commits and revert to previous state
        • See git/How To/Discard Changes to Working Dir for step-by-step instructions

    • Common Reference Points

      • HEAD~n: Move back n commits from current position
      • HEAD^: Move to parent commit
      • Commit hash: Reset to specific commit
      • Branch name: Reset to tip of another branch

  • Technical Details

    • Safety Considerations

      • Hard reset can permanently lose work

      • The Reflog git/reflog

        • Git's reference log (reflog) is a safety mechanism that records all changes to branch tips and HEAD
        • Maintains a local history of where HEAD and branch references have been
        • Entries persist for 30 days by default (configurable)
        • Common reflog commands:
          • git reflog: View the reflog history
          • git reflog show <branch>: View reflog for specific branch
          • git reset HEAD@{n}: Reset to nth previous HEAD position
        • Use cases:
          • Recover from accidental hard reset
          • Find lost commits after branch deletion
          • Undo git operations that moved HEAD
      • Recommended to create backup branch before major resets

    • Limitations

      • Cannot reset individual files in committed state
      • Does not work on untracked files
      • Cannot undo after pushing to remote (use Git/revert instead)

  • Related References

    • git/revert
    • git/checkout
    • git/clean
    • git/reflog