Re: dd SIGUSR1 race

[Bernhard Voelker]

On 09/26/2014 05:05 PM, Pádraig Brady wrote:
> Subject: [PATCH] dd: use more robust SIGUSR handling

s/USR/USR1/

> * src/dd.c (ifd_reopen): A new wrapper to ensure we
> don't exit upon receiving a SIGUSR1 in a blocking open()
> on a fifo for example.
> (iread): Process signals also after a short read.
> (install_signal_handlers): Install SIGINFO/SIGUSR1 handler
> even if set to SIG_IGN, as this is what the parent can easily
> set from a shell script that can send SIGUSR1 without the
> possiblity of inadvertently killing the dd process.
> * doc/corutils.texi (dd invocation): Improve the example to
> show robust usage wrt signal races and short reads.
> * tests/dd/stats.sh: A new test for various signal races.
> * tests/local.mk: Reference the new test.
> * NEWS: Mention the fix.

Another minor nit:
s/corutils/coreutils/

The rest LGTM.

What about adding "trap '' USR1;" to usage(), too?
You know, many folks are only reading that instead of the
texinfo manual.
OTOH, that stats-on-signal feature is such a detail that it may
be worth removing from the manpage at all.

Thanks & have a nice day,
Berny