shift at least...

[georgalis]

This has bitten me multiple times, not sure if there is a good place for it in the book?

When a function accepts optional parameters for arg1, and arg2, and unlimited additional parameters, this may look okay, but it does not work, use arg1, arg2, shift 2, then read remaining args in from $@

local a="$1" b="$2"
shift 2
local c="$@"

The desired effect is not achieved, because shift 2 doesn't shift any, and returns signal 1 (usually without detection), If only one or zero args are provided to the function. It's a mess to debug. This sets a and b to arg1 and arg2, and c to any remaining data, without any error signals, even if there are no args:

local a="$1" b="$2"
shift 2 || shift || true
local c="$@"

I was wondering if anyone has a less messy way to achieve that desired effect?

[oceanMIH]

maybe you can try this:

local a="$1" b="$2"
(( $# > 2 )) && { shift 2; local c=$@; }

[georgalis]

yes, testing the condition solves the unknown case. thanks!