Hacker News: pottmi

New comment by pottmi in "Advanced Shell Scripting with Bash (2006) [pdf]"

pottmi — Sat, 19 Apr 2025 15:17:27 +0000

I switched to zsh so I have not been paying attention to bash so I don't have a top three things to add. I just add things as I stumble on them.

Thanks for the tip on reference variables. definitely better than eval. i will add that to the presentation.

I will look into using set -u and what I can do with that and add it to the presentation. Perhaps make a companion presentation on debugging bash.

Another good presentation would be on how to use bash safely with sudo. I have a sudo presentation that is pretty good for it is for sudo 1.7 and the current version is 1.9 so I would need to update it before giving it.

I have not used associative arrays in bash. I would probably tend to use python if i needed that capability so I am not likely to use aa in bash soon.

Regarding nesting levels of self modifying variables: Yeah, I tried to do it once and failed and did not try to figure out any tricks to get it to work. I just moved to multiline which is easier to debug and comment on for the poor bastard that has to fix my code.

New comment by pottmi in "Advanced Shell Scripting with Bash (2006) [pdf]"

pottmi — Sat, 19 Apr 2025 14:46:50 +0000

It is what I advise people that want to make a presentation to give to their local LUG. Do the presentation on something "evergreen" that will last a long time. File permission, regular expression, /proc file system, ... Dig into the details and anytime you are surprised by something make a new slide. Also make "Cookbook" slides. pretty soon you have 30 slides and it is enough for a full presentation.

New comment by pottmi in "Advanced Shell Scripting with Bash (2006) [pdf]"

pottmi — Sat, 19 Apr 2025 14:41:45 +0000

Yeah, despite having created that presentation and having given it 50 times if I were to do another IBM JCL to shell conversion I would convert to zsh.

New comment by pottmi in "Advanced Shell Scripting with Bash (2006) [pdf]"

pottmi — Thu, 17 Apr 2025 17:15:19 +0000

You will like the final version of the traperr ERR function. It looks to create a "stack trace" type dump of where you are in the script when it fails.

See it here: https://github.com/pottmi/stringent.sh