prezto_config/modules/utility/functions/diff

#
# Highlights diff output.
#
# Authors:
#   Sorin Ionescu <sorin.ionescu@gmail.com>
#

function diff {
  if zstyle -t ':prezto:module:utility:diff' color; then
    if (( $+commands[colordiff] )); then
      command diff --unified "$@" | colordiff --difftype diffu
    elif (( $+commands[git] )); then
      git --no-pager diff --color=auto --no-ext-diff --no-index "$@"
    else
      command diff --unified "$@"
    fi
  else
    command diff --unified "$@"
  fi
}

diff "$@"