virtualenv_cd_alias

activator_suffix="bin/activate"

# Quick check to see if we're in a virtualenv directory.
function activate_global_cd {
    ROOT="$PWD"
    package=$(echo $PWD | awk '{n = split($0,a,"/"); print n }')
    for (( $package; package>0; package-- ))
    do
        activator="${ROOT}/$activator_suffix"
        python_binary="${ROOT}/bin/python"
	
        if [ -f "$activator" ]
        then
            if [ -f "$python_binary" ]
            then 
                echo "sourcing $activator"
                source "$activator"
            fi
        fi
        ROOT="$ROOT/.."
    done
    
}

# Detect whether we've entered or left a virtualenv directory.
function activate_cd {


    found=0
	
    ROOT="$PWD"
    package=$(echo $PWD | awk '{n = split($0,a,"/"); print n }')
    for (( $package; package>0; package-- ))
    do
        activator="${ROOT}/$activator_suffix"
        python_binary="${ROOT}/bin/python"
	
        if [ -f "$activator" ]
        then
            if [ -f "$python_binary" ]
            then 
                found=1
            fi
        fi
        
        ROOT="$ROOT/.."
    done
 	

    # Actually change directory
    if [ -z "$1" ]
    then
        cd ~
    else
        cd "$1"
    fi

    found2=0
	
    ROOT="$PWD"
    package=$(echo $PWD | awk '{n = split($0,a,"/"); print n }')
    for (( $package; package>0; package-- ))
    do
        activator="${ROOT}/$activator_suffix"
        python_binary="${ROOT}/bin/python"
	
        if [ -f "$activator" ]
        then
            if [ -f "$python_binary" ]
            then 
                found2=1 
                if [ $found -eq 0 ]
                then
                    echo "sourcing $activator"
                    source "$activator"
                fi
            
            fi
        fi
        
        ROOT="$ROOT/.."
    done

    if [[ $found -eq 1 && $found2 -eq 0 ]];then
        deactivate
    fi

}

alias cd='activate_cd'

# Always do a global search when starting a new terminal instance.
activate_global_cd