>elglob -0 fs somedir/*
>if { test -n $fs }
>ln -t otherdir $fs
>
>the test will fail if there’s more than one file in `somedir`.
>Is there a way to put a split variable into one variable again?
Your next door "echo" command will do just that (or s6-echo
if you risk having dashes and want reliable behaviour in all cases).
elglob -0 splitfs somedir/*
backtick -n fs { echo $splitfs }
importas -u fs fs
if { test -n $fs } ...
>It feels kind of clumsy to use elglob, especially because of
>the default verbatim input of the pattern if no expansion is
>found. I can’t imagine any use case where I’d want that,
>especially not as default behaviour.
The shell has the exact same default behaviour. I didn't want to
gratuitously diverge from the shell. But I agree "elglob -0" is the
behaviour you want most of the time.
>Another fun effect:
>
>>execlineb -c 'elglob -0 f doesnotexist/* if { test -z "${f}" } echo
>>foo'
>foo
>>execlineb -c 'elglob -0 f doesnotexist/* if { test -n "${f}" } echo
>>foo'
>foo
>
>So for `test`, the ominous “zero string” of execline is both
>empty and non-empty!
>Is there some elaboration somewhere what this zero string is?
>And how do work with it?
It's not a "zero string". It's zero word. Which means the "${f}"
argument is replaced with nothing at all, not even an empty string.
So the tests resolve to:
test -z
and
test -n
which both return true.
--
Laurent
Received on Tue Jul 24 2018 - 16:51:54 UTC