SC2086 should not complain about usage within set

[smoser]

It seems that SC2086 should not complain about usage with 'set'. In most cases if someone has unquoted strings in set -- $VAR then that was by design. Perhaps there could be another warning code for use in set -- specifically.

For bugs

• Rule Id: SC2086
• My shellcheck version: 0.4.6 and online
• I tried on shellcheck.net and verified that this is still a problem on the latest commit

For new checks and feature suggestions

• shellcheck.net (i.e. the latest commit) currently gives no useful warnings about this
• I searched through https://github.com/koalaman/shellcheck/issues and didn't find anything related

Here's a snippet or screenshot that shows the problem:

#!/bin/sh
foo="foo bar zee"
set -- $foo
echo "there were $# tokens in $foo"

Here's what shellcheck currently says:

$ shellcheck myscript
 
Line 3:
set -- $foo
       ^-- SC2086: Double quote to prevent globbing and word splitting.

Here's what I wanted or expected to see:

I'd like to not have to disable the check on that line and still get the generally-useful SC2086 globally.

[orbea]

You can avoid the warning with.

eval "set -- $foo"

However while this is safe in your example extra care should be taken to make sure you always control the variables when eval is used.

[koalaman]

I'm not sure this is a general issue with set. I'd argue for a warning even in this case because this doesn't seem intentional:

there were 182 tokens in foo * zee

There are also other reasons why you'd want such a warning:

var="hello world"
set -- --msgbox $var 6 40
dialog "$@"

If splitting/globbing is a generally an issue, but you've identified a specific case where it's not, then that's exactly what disable statements are for.

[smoser]

I had suggested "Perhaps there could be another warning code for use in set -- specifically.".
As @orbea said, you could use eval but that gets tricky anyway.

I'd much prefer just adding a warning specifically to 'set' that I could disable globally compared to in-line disable statements on each use.