header signal.h

This is a discussion on header signal.h within the C Programming forums, part of the General Programming Boards category; hi all... just a clarification... this is a function defined in the csignal library to handle (return(ed)?! - os?!) signals: ...

  1. #1
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    header signal.h

    hi all... just a clarification...

    this is a function defined in the csignal library to handle (return(ed)?! - os?!) signals:
    void (*signal(int sig, void (*func)(int)) ) (int);

    i interpret it as:

    a pointer to a void function that takes two arguments - a signal and a pointer to a function that itself needs an int arg. so far so good.

    what does the (int) at the very and do/set?!

    thanks....

  2. #2
    Chinese pâté foxman's Avatar
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    In fact, it means that the function "signal" return a function pointer, and this function return nothing (void) and takes one argument of type "int".

    The syntax is a bit hard to read. This is an equivalent syntax:

    Code:
    typedef void (*sighandler_t)(int);
    
    sighandler_t signal(int signum, sighandler_t handler);
    I hate real numbers.

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    thanks...

    pardon my ignorance but... why would you want to make a type out of a void function pointer?!

  4. #4
    Chinese pâté foxman's Avatar
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    pardon my ignorance but... why would you want to make a type out of a void function pointer?!
    Careful, here, "sighandler_t" is a synonym for "void (*)(int)". Why would we want to do such ? Well, it makes the syntax more concise.

    Is it clearer ?
    I hate real numbers.

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