<strong style="margin: 0px; padding: 0px; border: 0px; font-size: 15px; font-weight: bold; color: rgb(34, 34, 34); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-style: normal; font-variant: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: left; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">wrapper.c</strong>

#include <stdlib.h>

#include <string.h>

#include <sys/shm.h>

#include <sys/types.h>

int my_shm_open(char* filename, int open_flag){

    int shm_id;

    key_t key;

    key = ftok(filename, 0x03);

    if(key == -1){

        return -1;

    }

    if(open_flag)

        shm_id = shmget(key, 4096, IPC_CREAT|IPC_EXCL|0600);

    else

        shm_id = shmget(key, 0, 0);

    if(shm_id == -1){

        return -1;

    }

    return shm_id;

}

int my_shm_update(int shm_id, char* content){

    char* addr;

    addr = (char*)shmat(shm_id, NULL, 0);

    if(addr == (char*)-1){

        return -1;

    }

    if(strlen(content) > 4095)

        return -1;

    strcpy(addr, content);

    shmdt(addr);

    return 0;

}

int my_shm_close(int shm_id){

    shmctl(shm_id, IPC_RMID, NULL);

    return 0;

}

char* my_shm_read(char* filename){

    int shm_id;

    char* addr;

    char* s;

    shm_id = my_shm_open(filename, 0);

    if(shm_id == -1)

        return NULL;

    addr = (char*)shmat(shm_id, NULL, 0);

    if(addr == (char*)-1){

        return NULL;

    }

    s = (char*)malloc(strlen(addr) + 1);

    strcpy(s, addr);

    shmdt(addr);

    return s;

}

<strong style="margin: 0px; padding: 0px; border: 0px; font-size: 15px; font-weight: bold; color: rgb(34, 34, 34); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-style: normal; font-variant: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: left; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">reader.go</strong>

package main

// #include <stdlib.h>

// #include "wrapper.c"

import "C"

import "unsafe"

import "fmt"

func read(filename string) string {

    f := C.CString(filename)

    defer C.free(unsafe.Pointer(f))

    s := C.my_shm_read(f)

    defer C.free(unsafe.Pointer(s))

    return C.GoString(s)

}

func main() {

    fmt.Println(read("/tmp"))

}

<strong style="margin: 0px; padding: 0px; border: 0px; font-size: 15px; font-weight: bold; color: rgb(34, 34, 34); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-style: normal; font-variant: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: left; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">writter.go</strong>

package main

// #include <stdlib.h>

// #include "wrapper.c"

import "C"

import "unsafe"

import (

    "log"

    "time"

)

type errorString struct {

    s string

}

func (e *errorString) Error() string {

    return e.s

}

func open(file string) (int, error) {

    f := C.CString(file)

    defer C.free(unsafe.Pointer(f))

    r := int(C.my_shm_open(f, C.int(1)))

    if r == -1 {

        return 0, &errorString{"error"}

    }

    return r, nil

}

func update(shm_id int, content string) error {

    c := C.CString(content)

    defer C.free(unsafe.Pointer(c))

    r := int(C.my_shm_update(C.int(shm_id), c))

    if r == -1 {

        return &errorString{"update error"}

    }

    return nil

}

func close(shm_id int) error {

    C.my_shm_close(C.int(shm_id))

    return nil

}

func main() {

    id, err := open("/tmp")

    if err != nil {

        log.Fatal(err)

    }

    defer close(id)

    err = update(id, "hello world")

    if err != nil {

        log.Fatal(err)

    }

    time.Sleep(1e9 * 100)

}

这个是我在stackoverflower上提问别人回答的,还是不是太懂,先留着。