golang调用c语言代码-cgo方式

1.cgo简单调用

package main

/*
#include <stdio.h>
void print1(char* s){
    printf("print from c code: %s\n", s);
}
*/
import "C"

func main() {
    text := C.CString("ABC")
    C.print1(text)
}

官方文档：The Go file will have access to anything appearing in the comment immediately preceding（在…之前） the line import "C"

2.c结构体调用

package main

/*
typedef struct {
    char* name;
    int age;
} Student;
*/
import "C"
import "fmt"

func main() {
    var stu C.Student;
    stu.name = C.CString("test")
    stu.age = 20

    fmt.Println(C.GoString(stu.name))
    fmt.Println(stu.age)
}

C语言和Go语言字符串转换函数

func C.CString(goString string) *C.char
func C.GoString(cString *C.char) string
func C.GoStringN(cString *C.char, length C.int) string

3.c字符数组赋值

package main

/*
typedef struct {
    char name[255];
    int age;
} Student;
*/
import "C"
import "fmt"

const bufferSize = 255

/**
Golang字符串转换为C的字符数组
*/
func GoString2CCharArray(text string) [bufferSize]C.char {
    result := [bufferSize]C.char{}

    for i := 0; i < len(text) && i < bufferSize; i++ {
        result[i] = C.char(text[i])
    }

    return result
}
/**
C字符数组转换为Golang字符串
 */
func CCharArray2GoString(array [bufferSize]C.char) string {
    //func C.GoString(cString *C.char) string
    var result = C.GoString(&array[0])
    return result
}
func main() {
    var stu C.Student
    stu.name = GoString2CCharArray("name from go")
    stu.age = 20

    fmt.Println(CCharArray2GoString(stu.name))
    fmt.Println(stu.age)
}

4.访问c结构体数组

package main

/*
typedef struct {
    char* name;
    int age;
} Student;

Student student_list[2] = {{"A",20},{"B",21}};
*/
import "C"
import "fmt"

func main() {
    var stu C.Student
    for k, v := range C.student_list {
        stu = v
        fmt.Println("index: ", k)
        fmt.Println(C.GoString(stu.name))
        fmt.Println(stu.age)
    }
}