Re: Random Questions from Late at Night asnd Far Away

[Hans Boldt <boldt@xxxxxxxxxx>]

Joep Beckeringh wrote:
> According to Kernighan and Ritchie the implementation-defined limits of 
> a C compiler are contained within the limits.h header file. Short and 
> int should be 2 bytes minimum; long should be 4 bytes minimum.

At one time, the relative sizes of int, short, and long were defined by 
the relationship "sizeof(short) <= sizeof(int) <= sizeof(long)", where 
"sizeof(int)" was normally the preferred word size of the CPU in bytes. 
So it was possible that in certain implementations of the C compiler, 
all three types would map to the same size.

These days, I believe the current C standard is a bit more specific:

sizeof(char)      >= 1 (bytes)
sizeof(short)     >= 2
sizeof(int)       >= 2
sizeof(long)      >= 4
sizeof(long long) >= 8

which is a bit more useful from the point of view of software portability.

In practice, it's not that big a deal, and I've never seen a problem 
with mismatched integer sizes in all my years of C programming. Unless 
you know you need to store potentially very large integer or unsigned 
values, or you need to match some external interface, just declaring 
your numeric variables as int is normally good enough.

Cheers! Hans