Shell Scripting

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What are the most inscrutable lines of $SHELL you've ever written? (programming.dev)

submitted 1 year ago* (last edited 1 year ago) by [email protected] to c/[email protected]

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I'm sure some of you have absolute monstrosities of sigils (I know I do, in my .zshrc alone). Post them without context, and try and guess what other users's lines are. If you want to provide context or guess, use the markdown editor to spoiler-tag your guesses and explanations!

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[–] [email protected] 1 points 1 year ago

Corrections

First, a look at man termcap:

       ch   Move cursor horizontally only to column %1
       ct   Clear tabs

(j::) actually joins with no seperator. The character following the j is used to capture the separator. Nearly any character or paired bracket can be used, but colons are common. Other ways to write this which might have been more obvious: (j''), (j[]), (j<>). To actually join with colons, something like (j.:.) would have been used.

Full context

Zsh agressively sets tabstops to every 8 characters. This is in a function which I trap to the WINCH signal, to set the termstops to 4 using the $termcap sequences rather than the external command tput:

.on_winch(){
	# tabs
	local -a s
	repeat COLUMNS/$1 s+=(${termcap[RI]/\%p1\%d/$1}$termcap[st])

	# final
	print -rn $termcap[sc]${termcap[ch]//(\%i|\%p1|\%d)}$termcap[ct]${(j::)s}$termcap[rc]
}
.on_winch 4
trap '.on_winch 4' WINCH