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refp | on: A shell colon does nothing. Use it anyway
Yo, author here.

You are very much correct and I 100% agree with you, I have updated the first example to include a snippet where a proper env-var is used to show of the automatic diagnostic.

Thanks for your feedback, much much appreciated!

wolletd | parent | next
For a short-lived script, the `${1:?missing argument}` stuff may be useful, but usually, I want to print some longer usage or help text in the error case.

I usually go with something like this:

  set -eu
  
  function eusage() {
    echo "Usage: $0 <input-file> <output-file>" >&2
    echo "Error: $@" >&2
    exit 1
  }

  infile=${1:-}; shift || eusage "Missing input filename"
  outfile=${1:-}; shift || eusage "Missing output filename"
The `${1:-}` in this case evaluates to an empty string if `$1` is not set, but `shift` fails when there is no argument to remove.
| parent
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