Using a loop to call 'sequentially' named functions in C - c

Question

Say I have functions foo_1(), foo_2(),...foo_n()
How could I use a loop to call them, that is how could 'convert' a string to a function call:
for (i = 0; i < n; i++)
switch (fork()) {
case 0: //child process
*COMVAR+=m;
//call foo_i()
exit(4);
case -1:
exit(5);
}

Answer 1

You cannot have the compiler or runtime do this automatically in C, but you can manually list the function pointers and invoke them in a loop, i.e.:
// create your function prototype, which all functions must use
typedef void(*VoidFunc)(void);
// create the array of pointers to actual functions
VoidFunc functions[] = { foo_1, foo_2, foo_3 };
// iterate the array and invoke them one by one
int main(void)
{
for (int i = 0; i < sizeof(functions) / sizeof(*functions); i++)
{
VoidFunc fn = functions[i];
fn();
}
return 0;
}
Keep in mind that void func() is not the same as void func(void) in C.

Answer 2

Nope.
The best you can do involves an array of function pointers
#include <stdio.h>
typedef int (*fx)(void); // fx is pointer to function taking no parameters and returning int
int foo_1(void) { printf("%s\n", __func__); return 1; }
int foo_2(void) { printf("%s\n", __func__); return 2; }
int foo_three(void) { printf("%s\n", __func__); return 3; }
int main(void) {
fx foo[3] = { foo_1, foo_2, foo_three };
for (int k = 0; k < 3; k++) {
printf("foo[%d]() returns %d\n", k, foo[k]());
}
}
see code running on ideone

Answer 3

Generally , your approach isn't possible in C.
But you can do it by using switch statement.
Though you have to write little bit of code.
switch (n)
​{
case 1:
foo_1();
break;
case 2:
foo_2();
break;
case 3:
foo_3();
break;
.
.
.
case n:
foo_n();
break;
default:
// code to be executed if n doesn't match any constant
}

Answer 4

Higher level languages that have reflection such as Java is able to do such kind of operations, but C does not. In Java, you can do something like below:
You have a class named MyClass
public class MyClass {
public void myMethodName(String arg1);
}
You can use below flow to call myMethodName using String form.
Class myObject = new MyClass();
Class<?> c = Class.forName("MyClass");
Class[] argTypes = new Class[] { String[].class };
Method method = c.getDeclaredMethod("myMethodName", argTypes);
method.invoke(myObject, params);
Here is the official document: https://docs.oracle.com/javase/tutorial/reflect/member/methodInvocation.html