How to use git filter-branch In GIT

Let’s say you committed a large file, like a 15MB photo named gfg.jpg, in a previous commit. To completely erase it from Git’s history, use the following command in your project directory:

git filter-branch --force --index-filter \
'git rm --cached --ignore-unmatch path/to/gfg.jpg' \
--prune-empty --tag-name-filter cat -- --all

Explanation of the Command:

• git filter-branch: This command rewrites your Git branch history.
• –force: Forces the rewrite, even if it rewrites existing remote branches.
• –index-filter: Specifies a command to run on the index (staging area) for each commit.

• git rm –cached –ignore-unmatch path/to/gfg.jpg: This command removes the file from the index for each commit, effectively deleting it from history.
  • –cached: Removes the file from the staging area.
  • –ignore-unmatch: Prevents errors if the file doesn’t exist in all commits.

• –prune-empty: Removes commits that become empty after filtering (i.e., commits that only had the removed file).
• –tag-name-filter cat –: Keeps tags in sync with the rewritten history (use cat to pass the original tag name through).
• –all: Applies the filter to all branches.

Successful Removal Output:

If the file was successfully removed, you’ll see output similar to:

Rewrite ee94db7633eewdhu7b370512d95ejnd7dnuf6c8cf (2/2)
Ref 'refs/heads/master' was rewritten

Preventing Future Issues:

Update your .gitignore file to prevent accidentally committing similar files again.

• Force Pushing to Remotes : If you’ve already pushed the large file to a remote hosting platform (like GitHub), you’ll need to force push the changes to update the rewritten commits on the remote server.

• Important Note: Force pushing rewrites history on the remote server, which can disrupt other developers who have already pulled that branch. It’s recommended to:

• Consult with experienced Git users on your team before force pushing.
• Read about the consequences of force pushing before proceeding.

• Force Push Command:

git push origin --force --all

Simply removing a large file through a commit won’t truly eliminate it. Git stores all versions of files in its history, even deleted ones, to allow for easy recovery. This can lead to wasted disk space.

We will discuss the various approaches for removing a large file from the commit history in Git: