On Mon, Oct 15, 2012 at 5:18 PM, Nikolai Kondrashov
<nikolai.kondras...@redhat.com> wrote:
> On 10/16/2012 12:08 AM, Greg Wooledge wrote:
>>
>> Sidestepping the direct question for a moment, you could use a temporary
>> file instead of a command substitution to store the output. Then there
>> would be no subshell involved.
>
>
> Thanks, Greg. I don't like creating temporary files unnecessarily, so I went
> the route of using SHELLOPTS value instead and massaging it into a set of
> "set" calls on restore. Like this:
>
> declare -r shellopts="$1"
> declare -r on_pattern="^(${shellopts//:/|})\$"
> declare attr
>
> for attr in `set -o | awk '{print \$1}'`; do
> if [[ $attr =~ $on_pattern ]]; then
> set -o $attr
> else
> set +o $attr
> fi
> done
>
> Might need to do something with that awk invocation, though.
>
> Sincerely,
> Nick
>
Do not use for to iterate over the output of an unquoted command
substitution. Instead, use a while read loop.
See http://mywiki.wooledge.org/DontReadLinesWithFor and
http://mywiki.wooledge.org/BashFAQ/001
I also don't understand the point of using a regex like that, seems to
be way more complicated than it needs to be. A simple glob will
suffice here.
Assuming you're writing bash and not POSIX sh:
while read -r attr state; do
if [[ $shellopts = *:"$attr":* ]]; then
set -o "$attr"
else
set +o "$attr"
fi
done < <(set -o)
