Re: [PATCH] selftests: net: tcp_fastopen_backup_key.sh: fix shellcheck issue

[Anders Roxell]

On Thu, 15 Aug 2019 at 01:35, <Tim.Bird@xxxxxxxx> wrote:
>
>
>
> > -----Original Message-----
> > From: Anders Roxell
> >
> > When running tcp_fastopen_backup_key.sh the following issue was seen in
> > a busybox environment.
> > ./tcp_fastopen_backup_key.sh: line 33: [: -ne: unary operator expected
> >
> > Shellcheck showed the following issue.
> > $ shellcheck tools/testing/selftests/net/tcp_fastopen_backup_key.sh
> >
> > In tools/testing/selftests/net/tcp_fastopen_backup_key.sh line 33:
> >         if [ $val -ne 0 ]; then
> >              ^-- SC2086: Double quote to prevent globbing and word splitting.
> >
> > Rework to add double quotes around the variable 'val' that shellcheck
> > recommends.
> >
> > Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
> > ---
> >  tools/testing/selftests/net/tcp_fastopen_backup_key.sh | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tools/testing/selftests/net/tcp_fastopen_backup_key.sh
> > b/tools/testing/selftests/net/tcp_fastopen_backup_key.sh
> > index 41476399e184..ba5ec3eb314e 100755
> > --- a/tools/testing/selftests/net/tcp_fastopen_backup_key.sh
> > +++ b/tools/testing/selftests/net/tcp_fastopen_backup_key.sh
> > @@ -30,7 +30,7 @@ do_test() {
> >       ip netns exec "${NETNS}" ./tcp_fastopen_backup_key "$1"
> >       val=$(ip netns exec "${NETNS}" nstat -az | \
> >               grep TcpExtTCPFastOpenPassiveFail | awk '{print $2}')
> > -     if [ $val -ne 0 ]; then
> > +     if [ "$val" -ne 0 ]; then
>
> Did you test this in the failing environment?

I thought I did that but the environment wasn't exactly the same. =/

>
> With a busybox shell, I get:
>  $ [ "" -ne 0 ]
> sh: bad number
>
> You might need to explicitly check for empty string here, or switch to a string comparison instead:
> if [ "$val" != 0 ]; then

I'll do that instead.

Sending out a v2 shortly.

Cheers,
Anders

>
>    -- Tim
>
> >               echo "FAIL: TcpExtTCPFastOpenPassiveFail non-zero"
> >               return 1
> >       fi
> > --
> > 2.20.1
>