getc and "large" bytes

[Flash Gordon]

Jack Klein wrote, On 24/05/08 03:56:

I just want to ask all of you a few questions:

1. How many of you have actually ever worked on an implementation
where CHAR_BIT was greater than 8? Show of hands, please.

/me puts up two hands, one for each implementation

2. How many of you have actually ever worked on a hosted
implementation where CHAR_BIT was greater than 8, that fully supported
binary streams?
No.

3. How many of you have even heard of hosted environments, with full
support for binary streams, where CHAR_BIT is greater than 8?

How about the 9bit machines people have mentioned in the past? Did they
have C implementations with binary streams fully supported?

A more pertinent question would be about implementations where
sizeof(int)==1, and I've not heard of any.

 

[vippstar]

File Code:http://www.mindspring.com/~pfilandr...ng.com/~pfilandr/C/lists_and_files/file_lib.c
Examples of usage:http://www.mindspring.com/~pfilandr...om/~pfilandr/C/lists_and_files/file_collate.c
List code:http://www.mindspring.com/~pfilandr...ng.com/~pfilandr/C/lists_and_files/list_lib.c

stdin example:http://www.mindspring.com/~pfilandr/C/get_line/get_line.c

Thanks, I like the code. Is there any particular reason that you cast
rc to (char) before you assign it to the buffer?

 

[Chris Torek]

How about the 9bit machines people have mentioned in the past? Did they
have C implementations with binary streams fully supported?

There was a C compiler for the Univac in the basement, back
when I was at the University of Maryland. The Univac had
9-bit char, 18-bit short, 36-bit long.

I never used it though (the C compiler, I mean -- I barely ever
used the Univac, except as required for a few courses). I expect
it worked pretty much the same way as other ASCII-based systems on
that machine: there was a file format using "quarterwords" (9-bit
"bytes"; the native Univac "bytes" were 6-bit FIELDATA text), and
in general people just avoided setting the topmost bit(s). If you
*did* set the topmost bits, you got non-ASCII data in your "ASCII"
files, and it would transfer OK as long as you stayed "inside" the
Univac system, but bits 7 and 8 would disappear in various kinds
of I/O (because "quarterword" data would get transferred in 7 or
8 bit units to external hardware that worked in "anything other
than FIELDATA").

Systems with wildly different internal and external data representations
*do* teach one to learn about "internalizing" and "externalizing"
data, at least.

 

[lawrence.jones]

Are all possible unsigned char values required to be characters that
can be written and read?

Yes.

-- Larry Jones

But Mom, frogs are our FRIENDS! -- Calvin