Re: vanishing spaces

[Marc Chantreux <mc@unistra.fr>]

On Sat, Mar 30, 2024 at 08:18:30AM -0700, Ray Andrews wrote:

> % aptitude search '~i?name(nvidia)'

aptitude search '~i~nnvidia' for short. check it out:

	aptitude-doc-en: /usr/share/doc/aptitude/html/en/ch02s04s05.html

>     ... I have reason to capture the output of several versions of aptitude
> searches into a variable. I hope 'eval' is the right way:

about the vanishing spaces: it's because you need to protect them with
quotes both while reading and writing them:

bad:

	output=$( eval $* )
	echo $output

good:

	output="$( eval $* )"
	echo "$output"

Aside: I don't understand why you eval it. it's ok to write

	output="$( aptitude search '~i~nnvidia' )"

plus: I try to avoid eval as much as possible because it's fragile.
if your command is stored in "$@" with all the parameters set correctly,
you don't need eval:

	set -- aptitude search '~i~nnvidia'
	output=$( "$@" )

quotes are important here also as "$@" will be expanded as

	"aptitude" "search" "~i~nnvidia"

HTH,
marc