Someone

#!/bin/sh

if [ -z "$1" ]; then
        export TP_DEV_PREFIX_PATH="$PWD"
elif [ -d "$PWD/$1" ]; then
    export TP_DEV_PREFIX_PATH="$PWD/$1"
else
        export TP_DEV_PREFIX_PATH="$1"
fi

export PATH="$TP_DEV_PREFIX_PATH/usr/bin:$PATH"
export LD_LIBRARY_PATH="$TP_DEV_PREFIX_PATH/usr/lib"
export PKG_CONFIG_PATH="$TP_DEV_PREFIX_PATH/usr/lib/pkgconfig"

echo "Using path: " $TP_DEV_PREFIX_PATH

if [ -x "$SHELL" ]; then
        exec "$SHELL"
else
        exec /bin/sh
fi