A shell script to read in the env.* variables from a .versions.conf file and replace them while in this directory only. Restores them on exit. This is meant to override `cd.` TODO: Make the cd command actually work...

cd.sh

#!/usr/bin/env bash

###
# cd override
#
# This replaces the builtin cd command
###

function init_local_env() {
    SAVED_VAR=ENV$(echo $1 | sed -e s:/:_:g | tr "[:lower:]" "[:upper:]")_SAVED
    NEW_VARS=$(cat .versions.conf | grep -e '^env\.' | sed -e 's/^env.//g' | tr '\n' ':' | sed -e 's/:$//g')
    SAVED_IFS=$IFS
    IFS=":"
    for LINE in $NEW_VARS; do
        ENV_VAR=$(echo $LINE | sed -e s:=.*$::g)
        ENV_VAR_VAL=$(eval echo \$$ENV_VAR)
        if [[ -z $(eval echo \$$SAVED_VAR) ]]; then
            eval $SAVED_VAR="$ENV_VAR=$ENV_VAR_VAL"
        else
            eval $SAVED_VAR="$ENV_VAR=$ENV_VAR_VAL:\$$SAVED_VAR"
        fi
        eval $ENV_VAR=$ENV_VAR_VAL
    done
    IFS=$SAVED_IFS
    SAVED_VAR=
    SAVED_IFS=
    NEW_VARS=
    LINE=
    ENV_VAR=
    ENV_VAR_VAL=
}

function restore_local_env() {
    SAVED_VAR=ENV$(echo $1 | sed -e s:/:_:g | tr "[:lower:]" "[:upper:]")_SAVED
    SAVED_IFS=$IFS
    IFS=":"
    for LINE in $(eval echo \$$SAVED_VAR); do
        ENV_VAR=$(echo $LINE | sed -e s:=.*$::g)
        ENV_VAR_VAL=$(eval $LINE | sed -e s:^.*=::g)
        eval $ENV_VAR=$ENV_VAR_VAL
    done
    IFS=$SAVED_IFS
    eval $SAVED_VAR=
    SAVED_VAR=
    SAVED_IFS=
    LINE=
}

if [[ -z $1 ]]; then
    DIR=$HOME
else
    DIR=$1
fi

if [[ -e $(pwd)/.versions.conf ]]; then
    restore_local_env $(pwd)
fi

if [[ -e $DIR/.versions.conf ]]; then
    init_local_env $DIR
fi

# This line obviously does not work, and should be replaces with cd override voodoo
cd $DIR

DIR=