[Info-vax] C limitations, was: Re: VMS process communication

[bill]

On 4/23/2023 9:54 AM, Bob Eager wrote:
> On Sun, 23 Apr 2023 09:51:11 -0400, Arne Vajhøj wrote:
> 
>> On 4/23/2023 9:46 AM, bill wrote:
>>> On 4/22/2023 7:47 PM, Arne Vajhøj wrote:
>>>> True. In C the isdigit function would be much better than a range
>>>> check.
>>>
>>> A cute idea, but also a modern accretion. Early C didn't have it and as
>>> much as people like to say comparing a char to it's numeric value is
>>> not a good idea it was quite common at one time.  I know,
>>> because I was the one tasked with porting some of this code to Primix
>>> where the chars all had a different numeric value.  I don't know why
>>> they did it, but they did.
>>
>> Different people may have different definitions of "modern".
>>
>> isdigit is in C89 so it has been standard for over 30 years.
> 
> It's in the original K&R book, so that's back as far as 1978. Hardly a
> 'modern accretion'!

It is not in Ultrix-11 :-).  I assume that also means V7.
Don't remember it in System III.  Don't know when it came
about but I was already trying to port a lot of Univ C
programs by 1982.  A bit before C89.

bill