Unintelligible declaration of signal function

Nerox · 08-11-2004, 03:37 PM

Hi, I do not understand the following function declaration:

Code:

void (*signal(int signum, void (*handler)(int)))(int);

I only understand the int signum (the signal to be handled) and void(*handler)(int) (a pointer to a function which returns void and takes int, but...

What does the ending int means?
Why (*signal...) ?

The signal manpage says:

Quote:

signal returns the previous value of the signal handler, or SIG_ERR on error.

So, why is it declared as void?

Thanks In Advance.

itsme86 · 08-11-2004, 03:47 PM

This is further down in the man page:

Quote:

If you're confused by the prototype at the top of this
manpage, it may help to see it separated out thus:

typedef void (*sighandler_t)(int);
sighandler_t signal(int signum, sighandler_t handler);

Does that help clear it up?

Nerox · 08-11-2004, 03:58 PM

So... does it mean that signal function returns a pointer to the function handler which takes one integer?? Am i right??

itsme86 · 08-11-2004, 04:19 PM

Nerox · 08-11-2004, 04:45 PM

That's exactly what i want to know.

Thank you ever so much!