[LTP] [PATCH 2/2] Use SAFE_RUNCMD()

[Petr Vorel]

Hi Li, Metan,

> > And this makes me think more of the '.request_hugepages' story. The
> > needs_foo flags require the foo to be present on the system as hard
> > requirements. In some situations(i.e copy_file_range02.c), we probably need
> > to handle the soft situation, which means, the commands are only part of
> > the test requirement. So if it writing with .needs_cmds="xxx", it might
> > skip the whole test in setup() phase.
+1. This is similar to a general problem how to structure tests when you want to
use tst_brk() and cleanup function (having more unrelated tests in single C file
means one should try to avoid using tst_brk() when not needed).

> Indeed, there are couple of solutions for that, one of them would have
> all the arrays doubled and one of them would list hard requirement while
> the other soft requirements. Then we will end up with something as
> "need_cmds" and "wants_cmds". The second one would be more or less
> informative, the test may print a message "Missing foo command test
> coverage will be limited".
I was thinking about it and thought that would be too rich API (given there is
not that much external dependencies for C tests). But ok, sounds reasonable.

Also similar use case from shell tests: mostly $TST_NEEDS_CMDS is used,
which stop whole testing. But rarely (only in 3 tests and tst_net.sh) is used
tst_require_cmds() directly - it's a hard requirement, but it tries to run some
test before (or require it only when it's needed - tst_net.sh).
But that's bad from metadata point of view (you concentrate on metadata in C,
but sooner or later we'll need to handle shell as well).

Kind regards,
Petr