About a month ago, I added a couple shell scripts to my DFIR Github repository. Three of the four scripts are used at work daily in either a Linux terminal, or a Cygwin terminal. The fourth script is something I use to help with quarantined mail, and not really DFIR based.
b64Decode.sh and hexConvert.bash take command line arguments and reports back the result. For example:
~$ b64Decode.sh 4piiZXhjaXRpbmcgbmV3cw==