cgo中内置函数 - Sat, Oct 24, 2020
cgo中内置函数
1. 概述
cgo中有以下内置函数
// Go string to C string
// The C string is allocated in the C heap using malloc.
// It is the caller's responsibility to arrange for it to be
// freed, such as by calling C.free (be sure to include stdlib.h
// if C.free is needed).
func C.CString(string) *C.char
// Go []byte slice to C array
// The C array is allocated in the C heap using malloc.
// It is the caller's responsibility to arrange for it to be
// freed, such as by calling C.free (be sure to include stdlib.h
// if C.free is needed).
func C.CBytes([]byte) unsafe.Pointer
// C string to Go string
func C.GoString(*C.char) string
// C data with explicit length to Go string
func C.GoStringN(*C.char, C.int) string
// C data with explicit length to Go []byte
func C.GoBytes(unsafe.Pointer, C.int) []byte
2. 示例
CString
注意：必须释放内存
由于使用了free函数，所以需要#include <stdlib.h>头文件。
sDVRIP := C.CString(ip)
defer C.free(unsafe.Pointer(sDVRIP))
CBytes
注意：必须释放内存
由于使用了free函数，所以需要#include <stdlib.h>头文件。
sAddress := C.CBytes(address)
defer C.free(sAddress)
GoString 指针时
// char* ip = "192.168.1.168"
sAddress := C.GoString(ip)
数组时
// char ip[20] = "192.168.1.168"
sAddress := C.GoString(&ip[0])