Re: question: hard-coded file descriptors in stdin/stdout/stderr

[Szabolcs Nagy <nsz@port70.net>]

* Zvi Gilboa <zg7s@eservices.virginia.edu> [2013-03-14 12:18:53 -0400]:
> I just noticed that the file descriptors in stdin.c, stdout.c, and
> stderr.c do not use the #defines from <unistd.h> (namely
> STDIN_FILENO, STDOUT_FILENO, and STDERR_FILENO), but are rather
> hard-coded (as 0, 1, and 2 respectively).  I was therefore wondering

these numbers are fixed on posix (and linux and all historical unices)

the macro definitions are there for conformance reasons

it's like using 0 instead of NULL or -1U instead of UINT_MAX


> this would normally not be an issue, however there are still some
> systems out there with standard file descriptor numbers which are
> different...

which ones?

> On that same note: wouldn't it make sense to slightly modify
> unistd.h so that it first checks whether STDIN_FILENO, etc. have

i dont think it makes sense for a linux libc
to have these numbers configurable