creates git alias `sweep` to prune dead local branches

gitSweep.sh

#!/bin/bash

# description: 
# creates git alias 'sweep' that prunes all local branches merged 
# into master and optionally, via -f flag, branches that have been merged into 
# current branch. 

# usage: `git sweep [-f]` 

# create alias:
# copypasta script below and or save and run `chmod u+x $HOME/gitSweep.sh | . $HOME/gitSweep.sh`

git config --global alias.sweep \
  '!git branch --merged $([[ $1 != "-f" ]] && \
    git rev-parse master) | \
    egrep -v "(^\*|^\s*(master|develop|dev)$)" | \
    xargs git branch -d'