Shell script for configuring git aliases

git_aliases.sh

#!/bin/sh

CMD='git config --global alias'

add_alias() {
    ALIAS=`eval $CMD.$1`
    if [[ -z "$ALIAS" ]]; then
        eval "$CMD.$1 $2"
    elif [[ $ALIAS != $2 ]]; then
        printf "%-4s already defined as %s\n" $1 $ALIAS
    fi
}

add_alias a add
add_alias c commit
add_alias co checkout
add_alias d diff
# Arguments with more than one word need to be quoted and spaces must be escaped
add_alias dc 'diff\ --cached'
add_alias mt mergetool
add_alias pl pull
add_alias s status