Git Delete Merged Branches

When using Git, sometimes (often) I find myself forgetting to delete local branches after merging them. To resolve this, it would be great to have a command to delete branches that have been merged into the current branch. The following does the trick.

git branch --merged | grep -Ev "(^\*|^\s+master$)" | xargs git branch -d

How does this work?

Get Merged Branches

git branch --merged

Returns all of the branches that have been merged with our current branch, e.g.

$ git branch --merged
  already-merged-1
  already-merged-2
* develop
  master

Remove Current Branch and Master Branch

We use the results above with grep to filter our results.

grep -Ev "(^\*|^\s+master$)"

removes any lines that start with * or where the branch name is “master”. We do not want to remove the current branch (marked with *) nor the master branch.

-Ev The E sets grep to use “extended regular expression” interpretation and v indicates “Invert Match”

Extended Regular Expression

Generally when using regular expressions, meta characters (e.g. +, (, ), |) have special meanings. By default in grep, these special meanings are ignored. By using grep’s Extended Regular Expression feature, these characters have the same special meanings that are usually associated with regular expressions.

Invert Match

By default, grep returns the lines that match the given pattern. In these case, we want to return the lines, which do NOT match the pattern.

$ git branch --merged | grep -Ev "(^\*|^\s+master$)"
  already-merged-1
  already-merged-2

Delete Merged Branches

Now that we have our list of merged branches, we want to run git branch -d for each branch. We do this using the xargs command.

We pass our results (our two branches listed above) into xargs git branch -d, which then runs the command for each line in the results.

$ git branch --merged | grep -Ev "(^\*|^\s+master$)" | xargs git branch -d
Deleted branch already-merged-1 (was 927613f).
Deleted branch already-merged-2 (was 927613f).

is the same as running

$ git branch -d already-merged-1
Deleted branch already-merged-1 (was 927613f).
$ git branch -d already-merged-2
Deleted branch already-merged-2 (was 927613f).

The Easy Way

It would be nice to have a Git command to perform this (something like git branch-delete-merged). We can define this command by running the following from the command line.

git config --global alias.branch-delete-merged '!git branch --merged | grep -Ev "(^\*|^\s+master$)" | xargs git branch -d'

This adds an entry to our Git global configuration, which allows us to run

git branch-delete-merged

My Git Configuration

My Iron Code Git Enhancements includes this and other Git aliases and configurations that help me speed up my development workflow.

Inspired by this tweet

Fellow neat-freaks!

Add this to your .bash_profile and thank me later.

alias gcmb="git branch –merged | grep -Ev '(^*|master)' | xargs git branch -d"

It cleans all branches you’ve got locally that have already been merged.

— Safia (@captainsafia) November 3, 2018

Sal Ferrarello (@salcode)

Sal is a PHP developer with a focus on the WordPress platform. He is a conference speaker with a background including Piano Player, Radio DJ, Magician/Juggler, Beach Photographer, and High School Math Teacher. Sal can be found professionally at WebDevStudios, where he works as a senior backend engineer.