Settings that travel
Apps read their configuration — database URLs, ports, API keys — from environment variables. And PATH decides which program runs when you type a name. Knowing both ends many "command not found" and "works on my machine" mysteries.
Variables, PATH, aliases
NAME=Asha echo "Hello $NAME" bash -c 'echo "child sees: [$NAME]"' export PORT=8080 bash -c 'echo "child sees PORT=$PORT"' NODE_ENV=production bash -c 'echo $NODE_ENV' echo $PATH which ls type cd alias ll alias gs='git status' echo 'alias ll="ls -alF"' >> ~/.bashrc source ~/.bashrc