UNIX for Beginners Questions & Answers

Hello.. and thanks in advance for any help anyone can offer me to figure this out

I'm reading about the about the Bash shell... and I've read from many sources that to make Bash POSIX compliant it needs "extensions"... Which sounds to me like something I should be able to load or unload into Bash... I've tried googling the subject but can't seem to find any detail about this subject... What little I can find basically says nothing more than "Bash needs extensions"

Is there a way I can view the extensions Bash is loading? Load or unload them? Configure them differently?

Once again... thanks for any help!

Code:

#!/bin/bash --posix   # puts bash in POSIX mode

Note: bash in POSIX mode is not 100% POSIX guaranteed. It is really close.

The extensions are innate to bash. You do nothing special to make them switch on. You have to be aware of what ways turn them on, turn them off.

So you cannot view them. You may not know this, but you can add your own code and make it part of bash as well. This is not recommended because every upgrade/bugfix means you have to add your change back in.

Code:

#!/bin/bash

on the first line of the script invokes native bash. NOT POSIX.

Code:

#!/bin/sh

on the first line of the script invokes bash in POSIX mode. If /bin/sh is a symlink that points to bash

See: Difference between sh and bash * GitHub

Want to add bash extensions of your own? - examples:
http://cfajohnson.com/shell/date-fun...e-functions-sh