informal survey regarding <{}

informal survey regarding <{}

[Byron Rakitzis]

I was wondering if anyone in rc-land is using the <{} feature
with fifos.

Specifically, I've been thinking about ditching fifos in favor
of synchronous operation with tmp files.

Advantages:

	o You can seek on a tmp file, so diff will work.
	o tmp files are much closer in semantics to real pipes,
		so I expect fewer bugs.
	o fifos aren't present everywhere, files are.
	o fifos don't work everywhere (e.g., the notorious
		tmpfs bug), files do.

Disadvantages:

	o Existing users might depend on fifos.
	o Advantage of pipe in the kernel is lost; command must
		wait on all the tmp files being written first.

I could even argue, based on the first item in "Advantages",
that one might want to use tmp files even over /dev/fd, but
I don't want to risk starting a flame war.

Anyway, reply to me and I can summarize to the list.

Re: informal survey regarding <{}

[Scott Merrilees]

>I was wondering if anyone in rc-land is using the <{} feature
>with fifos.
>
>Specifically, I've been thinking about ditching fifos in favor
>of synchronous operation with tmp files.
>
>Advantages:
>
>	o You can seek on a tmp file, so diff will work.
>	o tmp files are much closer in semantics to real pipes,
>		so I expect fewer bugs.
>	o fifos aren't present everywhere, files are.
>	o fifos don't work everywhere (e.g., the notorious
>		tmpfs bug), files do.
>
>Disadvantages:
>
>	o Existing users might depend on fifos.
>	o Advantage of pipe in the kernel is lost; command must
>		wait on all the tmp files being written first.
>
>I could even argue, based on the first item in "Advantages",
>that one might want to use tmp files even over /dev/fd, but
>I don't want to risk starting a flame war.
>
>Anyway, reply to me and I can summarize to the list.

I'd be interested in the tmp file approach.  Fifos don't work under
risc/os 4.52.  I tried to write a /dev/fd file system for the kernel,
but am getting some kernel crashes because of undocumented
interfaces.

Is there anything wrong with having tmp files as the default, and
fifos & /dev/fd as options ?

Sm