On 2/4/22 11:35 AM, Adam Thornton wrote:
>
>
> On Thu, Feb 3, 2022 at 11:07 PM Ori Idan <ori@heliconbooks.com> wrote:
>
>     As for EOF it is 0xFF which is not always -1, depending if your
>     char is signed or unsigned.
>
>
> Ha!  You fell into my trap!  getc() returns an int!  (I don't know if 
> EOF is _always_ "all bits set", and even if it is, that's only -1 on a 
> twos-complement machine, if we want to head off into some real 
> pedantry...)
>
> The need to use feof() and ferror() at least appear in the BUGS 
> section on my Mac.  Linux is not so gracious.  The real bug, if you 
> ask me, which no one did, is that getc() and pals return an int rather 
> than a char, which is surprising and certainly has tripped me up 
> several times across the decades (and yes, I understand that since any 
> character value is a legal character to have gotten, you need some 
> other way of signalling an error).
This is prolly why the authors steadfastly refused to commit to a 
particular value for EOF. Instead, they said in essence, that it was a 
matter of agreement, convention, if you will, and that whatever value 
was chosen, it should NEVER be a legal character. I made it -1, for v7, 
cuz it worked... and I wanted so badly to get a working ratfor program 
that I sacrificed any semblance of technical rigor to make it copy a 
character, onscreen, in real time, live. Heck, and it only took me a 
couple of days to figure out all how to get it working, EOF was easy, 
STDIN and STDOUT, not so much.