On Sun, 27 Mar 2005, Otto Moerbeek wrote:

> > We haven't even begun to talk about POSIX compliance.  The above tests
> > show that OpenBSD doesn't comply with the POSIX output requirement
> > that the \ in continuation numbers is also to be counted in the line
> > length.  So a line of a maximum of 70 characters, the default output
> > line size, should have 69 digits and one \.  OpenBSD bc has 70 digits
> > and the \.
> 
> IMO Posix is ambiguous:
> 
> "Very large numbers shall be split across lines with 70 characters per
> line in the POSIX locale; other locales may split at different
> character boundaries. Lines that are continued shall end with a
> backslash ( '\' )."
> 
> I copied the behaviour from the original (4.2 iirc) BSD dc(1). Although 
> dc(1) and bc(1) are completly new implementations, I tried to stay close 
> to these originals. But if I'm wrong in this, I'm happy to change that.
> 

Hmmm, I am a bit confused.. Let's count, first OpenBSD bc(1):

[otto@fonzo:15]$ bc
10^70
100000000000000000000000000000000000000000000000000000000000000000000\
00
[otto@fonzo:16]$
1234567890123456789012345678901234567890123456789012345678901234567890

OpenBSD bc(1) outputs 69 digits, a backslash, followed by two digits.

Line lenght is 70.


But with GNU bc:

om@xs3:~$ bc
bc 1.06
Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.
10^70
10000000000000000000000000000000000000000000000000000000000000000000\
000
om@xs3:~$
1234567890123456789012345678901234567890123456789012345678901234567890

That's 68 digits, a backslash and 3 digits.
Line lenght is 69

I am not counting the newlines, as you can see.

	-Otto