frn.sh

Non-interactive shells don’t load initialization files, so bash -c 'declare -f' doesn’t output anything. But we can source it: bash -c 'source ~/.bashrc; hello'. Or even: bash -c 'hello() { echo "hi"; }; declare -f'.

It’s all about memory share in shell modes:

• source changes only affect current shell memory.

• export marks variables to be passed to child processes.

Subtile difference that can save us lots of debugging time.