A shell script to delete all local git branches except the one specified while calling it. It also checks if there are any unpushed changes and prompts user to choose the appropriate action including either aborting the operation or pushing the changes

delete-all-local-branches-except.sh

#! /bin/bash

# declare colors
Red=$'\e[1;31m'
Green=$'\e[1;32m'
Blue=$'\e[1;34m'
Yellow=$'\e[1;33m'

# exit when any command fails
set -e

## declare the passed branch name
passedBranchName=""
## declare the branches except the one passed
BRANCHES=""

## check if a branch name is passed via a function
function isBranchNamePassed() {
        if [ -z "$1" ]; then
                echo "${Red}Please pass a branch name!"
                return 1
        else
                passedBranchName="$1"
        fi
}
isBranchNamePassed "$1"

## check if the passed branch exists
function doesBranchExist() {
        if ! git show-ref --verify --quiet refs/heads/"$1"; then
                echo "${Red}Branch $Yellow$1 ${Red}does not exist!"
                return 1
        fi
}
doesBranchExist "$passedBranchName"

## check if the passed branch is the current branch
## switch to the passed branch if it is not the current branch
function moveToPassedBrachIfNotAlreadyIn() {
        if [ "$(git symbolic-ref --short -q HEAD)" != "$1" ]; then
                echo "${Blue}Moving move to branch $Yellow$1!"
                git checkout "$1" --quiet
        fi
}
moveToPassedBrachIfNotAlreadyIn "$passedBranchName"

## check if there are other local branches except the one passed
function isThereAnyLocalBranchesExceptTheOnePassed() {
        if [ -z "$(git branch | grep -v "$1" | xargs)" ]; then
                echo "${Red}No local branches to delete except $Yellow$1"
                return 1
        else
                BRANCHES=$(git branch | grep -v "$1" | xargs)
        fi
}
isThereAnyLocalBranchesExceptTheOnePassed "$passedBranchName"

## loop through the branches and
## check if there are any unpushed changes
## prompt the user to push them if there are any
## then delete the branch
function askDeletionOfUnpushedBranch() {
        ## prompt the user if he/she wants to abort the operation
        ## for this specific branch
        echo -n "Abort the operation for this specific branch? (y/n) "
        read -r answerA </dev/tty # read from keyboard

        ## exit if the answer is not yes or continue otherwise
        if [ "$answerA" != "${answerA#[Yy]}" ]; then
                echo "${Green}Aborted..."
                return
        else
                echo "${Blue}Continuing to delete the brach..."
                # delete the specific branch as all the checks are passed
                git branch -D "$1" --quiet

                # show a message ensuring the branch is deleted
                echo "***** ${Green}Deleted the $Yellow$1 *****"
        fi
}
function checkAndDeleteBranches() {
        for currentBranch in $1; do
                echo "${Blue}Checking availabity for $Yellow$currentBranch"

                commits=$(git log "$currentBranch" --not --remotes --simplify-by-decoration --decorate --oneline)

                ## check if there are any unpushed changes for this specific branch
                if [ -z "$commits" ]; then
                        # delete the specific branch as all the checks are passed
                        git branch -D "$currentBranch" --quiet

                        # show a message ensuring the branch is deleted
                        echo "***** ${Green}Deleted the $Yellow$currentBranch *****"
                else
                        echo "${Red}There are unpushed changes in branch $Yellow$currentBranch"
                        echo "${Yellow}****************************************************"
                        echo "${Blue}$commits"
                        echo "${Yellow}****************************************************"
                        echo -n "${Red}Push them? (y/n) "
                        read -r answerP </dev/tty # read from keyboard

                        ## exit if the answer is not yes or continue otherwise
                        if [ "$answerP" != "${answerP#[Yy]}" ]; then
                                echo "${Blue}Pushing changes..."
                                git push origin "$currentBranch" --quiet
                                echo "${Green}Pushed changes for branch $Yellow$currentBranch"
                        else
                                askDeletionOfUnpushedBranch "$currentBranch"
                                continue
                        fi
                fi
        done
}
checkAndDeleteBranches "$BRANCHES"

• Add it to a location with appropriate rights.
• Provide an alias in your .zshrc or .bashprofile file.
• Call it inside your repository with the argument (the branch name you want to keep and delete all others)