C Syntax

Like any other programming language has a specific syntax, for C that will be shown in the sample code below. An indepth explanation of each keyword will not be done.

/*********************************************************
* This is a multi-line comment at the beginning
* of the code. You may enter a documentation here.
*********************************************************/

#include <stdio.h>  // look into system library only
#include "stddef.h" // look into directory first

extern int asm_main(void);  // Define any external elements

int integer;    // global variables

/**
* Def elements always before they are used
* So any function should be put before the main
* function.
*/
int modulo(int a, int b){
    if ( !(a >= b) )    // "not a >= b" -> "a < b"
        return a;
    return modulo(a-b, b);  // recursive call
}

/**
* main function
* argc: amount of arguments
* argv: arguments. similar to char[][]
* NOTE: argv[0] is the program name
* argv[1] is the first argument
* You can use `int main(void)` instead if no args needed
*/
int main(int argc, char ** argv){
    // define any needed local variables
    int a = 10;
    int b = 3;
    int tenModThree = modulo(a, b);

    // both print functions do the same here
    printf("10 mod 3 = %d", tenModThree);
    fprintf(stdout, "10 mod 3 = %d", tenModThree);

    // exit program with exit code 0, non-zero = error code
    return 0;
}