in c: func(void) vs. func() [duplicate]

void means the function does not take any parameters. For example,

int init (void)
{
    return 1;
}

This is not the same as defining

int init ()
{
    return 1;
}

because in the second case the compiler will not check whether the function is really called with no arguments at all; instead, a function call with arbitrary number of arguments will be accepted without any warnings (this is implemented only for the compatibility with the old-style function definition syntax, pre-ANSI).

IIRC func(void) in C will declare a function that takes no parameters whereas func() declares a function that will take any number of parameters. I believe the latter is an artifact coming from pre-ANSI C.

According to Wikipedia here, the declaration func() does basically declare the function "without information about the parameters".