Re: No such device or address when opening /dev/fd/<x> on opened /dev/tcp socket

[Chet Ramey]

On 4/5/21 1:31 PM, konsolebox wrote:
> Not sure if this is a bug or a limitation but this works:
>
> # echo a | ( exec {fd}>/path/to/regular/file; tee /dev/fd/"$fd" )
>
> While this produces a "No such device or address" error:
>
> # echo a | ( exec {fd}>/dev/tcp/host/port; tee /dev/fd/"$fd" )

There's no guarantee that file descriptors opened with socket(2) show up in
/dev/fd. Bash doesn't emulate /dev/fd if the system provides it, so it's up
to the OS on those systems whether they do or not.

It doesn't generate that error on macOS, for instance, which has /dev/fd.

--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/