prezto/functions/update-omz

# Update OMZ
# Jonathan Dahan <jonathan@jedahan.com>

# There are two options that can be added to your zshrc
#
# If upstream is a branch other than origin, add
#
#   zstyle ':omz:function:update-omz' upstream 'my-upstream-branch'
#
# To automatically commit from upstream, add
#
#   zstyle ':omz:function:update-omz' auto-commit 'yes'
#
# If you really need auto-updating and do not care about losing data, try
#
#   ( [ ! -f ~/.omz-update ] || [ ~/.omz-update(Nmh+6) ] ) && update-omz && touch ~/.omz-update

zstyle -t ':omz:function:update-omz' auto-commit || local nocommit='--no-commit'
zstyle -t ':omz:function:update-omz' upstream '_upstream'
zstyle -t ':omz:function:update-omz' color '_color'

local current_path=$PWD
cd $OMZ_HOME || return 1

if git pull --rebase $nocommit --strategy=recursive -X ours ${_upstream:-origin} master && git submodule update --recursive; then
  is-true _color && printf "$FG[blue]"
  printf 'Hooray! oh-my-zsh is up-to-date :)\n'
else
  is-true _color && printf "$FG[red]"
  printf 'Oh no! There was an error updating oh-my-zsh :(\n'
fi

unset _color
cd "$current_path" || return 1