Re: weird interaction between builtin cat and trap

[Peng Yu]

On 4/18/22, Chet Ramey <chet.ramey@case.edu> wrote:
> On 4/15/22 2:34 PM, Peng Yu wrote:
>
>>> The `same behavior' here is dying due to SIGPIPE before checking for a
>>> write error. Is that the hill you're dying on?
>>
>> The point is that this error for builtin cat should be ignored.
>
> So EPIPE should be ignored.
>
>> Another way to demonstrate the problem is the even simpler code. There
>> is no point to generate this kind of error. Otherwise, the external
>> cat would have done so already.
>
> This is just another example of the same scenario.
> There's nothing new
> here.

Yes and no. "No" in the sense, that `some_command_general_long_output
| cat | head` is a common enough use case for with SIGPIPE error
should not result in an error message. Users mostly likely don't want
to see the SIGPIPE error message but just the first 10 lines output by
head.

> You want SIGPIPE-before-write-error behavior and the builtin cat
> doesn't do things in that order.

-- 
Regards,
Peng