Re: readv() return and errno

[Andries.Brouwer@cwi.nl]

    From jholly@cup.hp.com Tue Mar 26 18:13:40 2002

    Doesn't seem confusing at all.

    RETURN VALUE
           On  success  readv  returns  the number of bytes read.  On
           success writev returns the number of  bytes  written.   On
           error, -1 is returned, and errno is set appropriately.

    ERRORS
           EINVAL An  invalid  argument was given. For instance count
                  might be greater than MAX_IOVEC, or zero.  fd could
                  also  be  attached to an object  which  is  unsuit-
                  able  for  reading  (for  readv)  or  writing  (for
                  writev).

    I don't see much in the way of waffle words. If count is greater than
    MAX_IOVEC or zero you get EINVAL.

Yes, without hesitation you choose the wrong interpretation.
That is why I explained in so much detail what the right
interpretation is. Since you perhaps still do not understand,
let me reiterate:

The above ERRORS section says: In case this call returns EINVAL
one of the possible reasons is that an invalid argument was given.
There do exist Unix-like systems (not necessarily Linux) that
consider a zero count invalid.

Andries