Edit Question - KnowledgeHub

Title Body

I came across this piece of code and completely got lost interpreting its meaning. #include <signal.h> void (*signal(int sig, void (*func)(int)))(int); What is a detailed explanation for the code at line 2? I know that void and int are types, the *func is a pointer for a function, and the brackets are for priority. But I still don't get the (*signal ...), the (int), and the whole thing combined together. The more detailed, the better. Probably I've known the meaning/effect of this declaration. But I had to make some more trials to help me understand what's going on, as below: 1 #include <signal.h> 2 void (*signal)(int sig, void (*func)(int)); 3 void (*signal)(int); // then void (signal)(int) again. 4 //void (*signal(int sig, void (*func)(int)))(int); //break this line into two lines above 5 6 int main(){} In the above code, I broke void (*signal(int sig, void (*func)(int)))(int) into two lines. For line 3, I tried both void (*signal)(int) and void (signal)(int) , with the same error result that indicated that I was trying to redeclare signal : TestDeclaration.c:2: error: 'signal' redeclared as different kind of symbol /usr/include/signal.h:93: error: previous declaration of 'signal' was here TestDeclaration.c:3: error: 'signal' redeclared as different kind of symbol /usr/include/signal.h:93: error: previous declaration of 'signal' was here Now I know both the trials are incorrect ways of declaration, but why are they incorrect? Why is the original way of declaration NOT a redeclaration?

Tags (comma-separated) Cancel