Portability / compatibility issues

[Chuck F.]

I'd be very surprised if it had been. What arguments can you
provide that this would be a Good Thing(tm)?

I am repeating my argument from another thread here. Here it
doesn't require a subject change

You are looking at it solely from a debugging viewpoint. On the
other hand, it is highly preferable to save volatile data than to
crash because some meaningless display had no data with which to
update. The "(null)" display can also serve as a debugging aid.

I am firmly in the camp that believes functions should interpret
illegal parameters in a sensible way if possible. Treating NULL as
an empty source string certainly qualifies.

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[Jordan Abel]

Keith Thompson said:

OzBob wrote:
[...]
# gcc -std=c99 -pedantic -W -Wall -O test.c
test.c:25: warning: return type of `main' is not `int'

Note: This is not to be taken lightly -- in principle, all
bets are off for a "void main" main().

In principle, yes. But in fact, I've never seen a C compiler that
misbehaves really badly given a "void main" declaration.

If you're prepared to generalise this to "given a declaration of main that
returns something other than int", I can vouch for the fact that I once
managed to crash Windows NT in a most colourful way by experimenting with
double main(void)!

Ah - the '!' invokes undefined behaviour.

Actually, that'd be a syntax error.

 

[Jordan Abel]

I'd be very surprised if it had been. What arguments can you provide
that this would be a Good Thing(tm)?

That it's how things were done in the original implementation [absent
some real reason to change it] isn't good enough? How about an easy way
to make a debug printf for a variable that may either point at a
null-terminated string or be NULL?

 

[Keith Thompson]

in comp.lang.c: [...]

more data points: On glibc, freebsd, and 7th edition UNIX, it's
"(null)" - i'm surprised this wasn't codified into the standard, given
its age.

I'd be very surprised if it had been. What arguments can you provide
that this would be a Good Thing(tm)?

That it's how things were done in the original implementation [absent
some real reason to change it] isn't good enough? How about an easy way
to make a debug printf for a variable that may either point at a
null-terminated string or be NULL?

printf("s = %s\n", s ? s : "(null)");