Re: [Qemu-devel] [PATCH] tests: Handle $RANDOM not being supported by the shell

[Stefan Hajnoczi]

On Fri, Jul 14, 2017 at 11:45:17AM +0100, Peter Maydell wrote:
> In various places in our test makefiles and scripts we use the
> shell $RANDOM to create a random number. This is a bash
> specific extension, and doesn't work on other shells.
> With dash the shell doesn't complain, it just effectively
> always evaluates $RANDOM to 0:
>   echo $((RANDOM + 32768))     => 32768
> 
> However, on NetBSD the shell will complain:
>   "-sh: arith: syntax error: "RANDOM + 32768"
> 
> which means that "make check" fails.
> 
> Switch to using "${RANDOM:-0}" instead of $RANDOM,
> which will portably either give us a random number or zero.
> This means that on non-bash shells we don't get such
> good test coverage via the MALLOC_PERTURB_ setting, but
> we were already in that situation for non-bash shells.
> 
> Our only other uses of $RANDOM (in tests/qemu-iotests/check
> and tests/qemu-iotests/162) are in shell scripts which use
> a #!/bin/bash line so they are always run under bash.
> 
> Suggested-by: Eric Blake <address@hidden>
> Signed-off-by: Peter Maydell <address@hidden>
> ---
>  tests/Makefile.include | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Stefan Hajnoczi <address@hidden>

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