Golang golang-cgo (snippet)

Go programming example 'golang-cgo'

golang-cgo

Golang beginners example: golang-cgo

package main

/*
#include <stdio.h>
#include <stdlib.h>

void print(char* s) {
    printf("%s", s);
}

long factorial(int n) {
    if (n == 0) {
        return 1;
    } else {
        return (n * factorial(n - 1));
    }
}

long gcd(long a, long b) {
    if (b == 0) {
        return a;
    } else {
        return gcd(b, a % b);
    }
}

void prime(int n) {
    int i = 0, count, c;
    for (count = 2; count <= n + 1; ) {
        for (c = 2; c <= i - 1; c++ ) {
            if (i % c == 0) {
                break;
            }
        }
        if (c == i) {
            printf("%d ", i);
            count++;
        }
        i++;
    }
    print("\n");
}

int fibonacci(int n) {
    if (n == 0) {
        return 0;
    } else if (n == 1) {
        return 1;
    } else {
        return (fibonacci(n - 1) + fibonacci(n - 2));
    }
}

*/
import "C"

import (
    "fmt"
    "unsafe"
)

func main() {
    fmt.Print("C.print: ")
    cs := C.CString("Hello from cgo\n")
    C.print(cs)
    C.free(unsafe.Pointer(cs))

    fmt.Print("C.factorial: ")
    fmt.Println(C.factorial(5))

    fmt.Print("C.gcd: ")
    fmt.Println(C.gcd(15, 230))

    fmt.Print("C.prime: ")
    C.prime(6)

    fmt.Print("C.fibonacci: ")
    fmt.Println(C.fibonacci(5))
}

Useful links

• Learn Go: https://golangr.com
• Download Go: https://golang.org