up - a bash script that updates either a git or an svn repo

up.sh

#!/usr/bin/env bash
#
# up - a bash script that updates either a git or an svn repo.
#
# Copyright (c) 2012 Trevor Lalish-Menagh
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#

NULL="/dev/null"
ENV="/usr/bin/env"
GIT="${ENV} git"
NOT_A_GIT_REPO="128" # a 128 error occurs when git is run not in a git repo.
SVN="${ENV} svn"
NOT_AN_SVN_REPO="Skipped '.'" # When svn update is run not in an svn repo.

${GIT} pull --rebase 2> ${NULL}; GIT_ERROR_CODE=$?
if [ "${GIT_ERROR_CODE}" == "${NOT_A_GIT_REPO}" ]; then
SVN_RESULT="$(${SVN} update 2> ${NULL})"
    if [ "${SVN_RESULT}" == "${NOT_AN_SVN_REPO}" ]; then
echo "Update failed. Are you in a git or svn repo?"
    else
echo "${SVN_RESULT}"
    fi
fi