Micro-optimisation #9725: Checkout the mainline

Very soon (October 1, 2020) Github will be making main the default branch of all new repositories instead of master. While you make the transition over to the new naming convention, it's handy to have an abstraction over the top for frequently-issued commands. For me, git checkout master is one of my faves, so much so that I've already aliased it to gcm. Which actually makes this easier - main and master start with the same letter...

Now when I issue the gcm command, it'll check if main exists, and if not, try master and remind me that this repo needs to be migrated. Here's the script

~/bin/checkout-main-or-master.sh:

#!/bin/bash

# Try main, else master and warn about outdated branch name

MAIN_BRANCH=`git branch -l | grep main`

if [[ ! -z ${MAIN_BRANCH} ]]; then
  git checkout main
else 
  echo "No main branch found, using master... please fix this repo!"
  git checkout master
fi

I run it using this alias:

alias gcm='~/bin/checkout-main-or-master.sh'

So a typical execution looks like this:

mymac:foo john$ gcm
No main branch found, using master... please fix this repo!
Switched to branch 'master'
Your branch is up to date with 'origin/master'.       
mymac:foo john$