Simple script to keep the local and remote origin of forked repos fresh

git-update.sh

#!/bin/bash

if [[ -z "${1}" ]] || [[ "${1}" == "-h" ]] || [[ "${1}" == "--help" ]]
then
  echo "This is a simple script to keep the local and remote of your forked"
  echo "repositories fresh. It does so by:"
  echo "  1. Detecting if the repo's origin and upstream are different (indicating"
  echo "     a fork)"
  echo "  2. Performing a \`fetch --all\` on the repo to update from origin and"
  echo "     upstream"
  echo "  3. Pushing any changes to the repo's origin to keep it updated, as well"
  echo ""
  echo "Usage: git-update.sh <search-path> <ssh-certificate>"
  echo ""
  echo "Please specify a path for the script to use to find git repositories."
  echo ""
  echo "Optionally, specify the path of a SSH certificate if one is needed for"
  echo "accessing/updating the repositories in the search path. This should also"
  echo "be provided if your SSH cert is password protected so the script will"
  echo "only request your password once."
  echo ""
  exit
fi

if [ ! -z "${2}" ]
then
  eval $(ssh-agent) 1>/dev/null
  ssh-add "${2}"
  gitparams="'ssh -i ${2}'"
  echo "${gitparams}"
fi

echo ""
echo "Searching for .git directories in "$(realpath ${1})

for repo in $(find "${1}" -name .git -type d)
do
  dirname="${repo::-4}"
  
  # This checks to see if the upstream and origin are different (indicating a fork)
  if [[ $(git -C "${dirname}" remote get-url upstream 2>/dev/null) != "" ]] && \
     [[ $(git -C "${dirname}" remote get-url origin) != $(git -C "${dirname}" remote get-url upstream 2>/dev/null) ]]
  then
    # Get the current and default (i.e. master/main) branch names
    current=$(git -C "${dirname}" rev-parse --abbrev-ref HEAD)
    default=$(git -C "${dirname}" symbolic-ref refs/remotes/origin/HEAD | sed 's@^refs/remotes/origin/@@')
    echo "Updating $(basename $(git -C "${dirname}" rev-parse --show-toplevel 2>/dev/null) 2>/dev/null):${default} in ${dirname}"
    
    # If the current and default branch names are different, the repo is
    # currently on a branch other than the default. Stash any changes
    if [[ "${current}" != "${default}" ]]
    then
      git -C "${dirname}" stash &>/dev/null
    fi
  
    # Switch to the master branch and `fetch --all`
    git -C "${dirname}" switch ${default} &>/dev/null
    git -C "${dirname}" fetch --all 2>&1 | sed "s/^/    /"

    # Push any updates to the remote origin    
    if [ ! -z "${2}" ]
    then
      GIT_SSH_COMMAND="ssh -i ${2}" git -C "${dirname}" push origin  "${current}" 2>&1 | sed "s/^/    /"
    else
      git -C "${dirname}" push origin  "${current}" 2>&1 | sed "s/^/    /"
    fi

    # If necessary, switch back to the previous branch and restore the stash
    git -C "${dirname}" switch ${current} &>/dev/null
  
    if [[ "${current}" != "${default}" ]]
    then
      git -C "${dirname}" stash pop &>/dev/null
    fi

    echo ""
  fi
done