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Comment by eltoozero | Hacker News Reader

Sometimes - perhaps often - you are in situations where you have no control over the shell, in these cases writing "portable" shell scripts is helpful.

I have been enjoying "Beginning Portable Shell Scripting"[0] by Peter Seebach for this very reason.

[0]https://www.apress.com/us/book/9781430210436

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I would like to second this recommendation. I have found "Beginning Portable Shell Scripting" to be invaluable --- and far more comprehensive than I expected given the "Beginning" in the title.

I highly recommend it (and the POSIX docs) to anyone who is is interested in portable shell programming.

---Alex

  $ cat run-bash-script.sh
  #!/bin/sh
  which bash &>/dev/null && exec bash "$@"
  source /etc/os-release
  case "$ID" in
    debian) apt install bash || exit 1 ;;
    redhat|suse) yum install bash || exit 1 ;;
    arch) pacman -S bash || exit 1 ;;
    alpine) apk add bash || exit 1 ;;
  esac
  exec bash "$@"

I don't know how to detect and handle the BSDs etc., but you get the idea. ;)

Also known as, "it's easier to port a shell than a shell script" :)

Now go try that on AIX boxes, in banks, where you don't get root/sudo.

You also don't get internet access, in case a bright bulb tries to go "curl ...".

Though in many of these cases I'd just advise leaving the premises unless the salary is stellar (or there are other considerations such as family, etc).

On the DevOps side of things (Contracting in London) the day rate at banks is about 1.5x everywhere else which can be nice. Just as long as you're happy never getting anything done ever.

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