void foo(void)
{
static int *my_errno=NULL;
if(my_errno==NULL) my_errno=errno;
// code that uses 'my_errno' as if it were 'errno'
}
No, this is not legal code under the POSIX standard at all.
Since this code is single-threaded only, what POSIX standard are you talking
about? The pthreads
void foo(void)
{
static int *my_errno=NULL;
if(my_errno==NULL) my_errno=errno;
// code that uses 'my_errno' as if it were 'errno'
}
No, this is not legal code under the POSIX standard at all.
Since this code is single-threaded only, what POSIX standard are you talking
about? The
Well, I'm late to this discussion, but it would seem to me that quite
a few things are wrong with that ...
First, my_errno=errno; might be more appropriate, after all, you need
to reference the address of errno, not the current value, right? But that
would also assume errno is declared as
The answer is that if you're compiled single-threaded, it's
perfectly legal.
If you're multi-threaded, it's not.
I guess by legal you mean that it has defined behaviour.
Yes, that's correct.
Both the C99 standard and SUS have this nice warning in it. In C99:
errno
