动态库的使用

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2023-12-01

socketclient.c

创建动态库工程

在release文件夹下生成如下文件

socketclient.dll 动态库，函数二进制码的集合
socketclient.lib 资源描述文件，描述 socketclient.dll

#define  _CRT_SECURE_NO_WARNINGS 
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "itcastlog.h"

typedef struct _SCK_HANDLE
{
    char    version[64];
    char    ip[128];
    int        port;
    unsigned char    *p;
    int        plen;
}SCK_HANDLE; //动态库 内部的数据类型 ，不想让测试程序（上层应用知道）
//数据类型的封装

__declspec(dllexport)
int cltSocketInit(void **handle /*out*/)
{
    int        ret = 0;
    SCK_HANDLE *hdl = NULL;
    ITCAST_LOG(__FILE__, __LINE__, LogLevel[2], ret, 
               "func cltSocketInit() Begin 22222:%d", ret);

    hdl = (SCK_HANDLE *)malloc(sizeof(SCK_HANDLE));
    if (hdl == NULL)
    {
        ret = -1;
        ITCAST_LOG(__FILE__, __LINE__, LogLevel[4], ret, 
                   "func cltSocketInit() err:%d", ret);
        return ret;
    }
    memset(hdl, 0, sizeof(SCK_HANDLE)); //把指针所指向的内存空间 赋值成 0；

    strcpy(hdl->ip, "192.168.6.254");
    hdl->port = 8081;
    *handle = hdl;

    ITCAST_LOG(__FILE__, __LINE__, LogLevel[2], ret, 
               "func cltSocketInit() End:%d \n", ret);

    return ret;
}

//客户端发报文
__declspec(dllexport)
int cltSocketSend(void *handle /*in*/, unsigned char *buf /*in*/,  
                  int buflen /*in*/)
{
    int        ret = 0;
    SCK_HANDLE *hdl = NULL;

    if (handle==NULL || buf==NULL )
    {
        ret = -1;
        ITCAST_LOG(__FILE__, __LINE__, LogLevel[4], ret, 
                   "func cltSocketSend() err:%d\n  (handle==NULL || buf==NULL ) ", 
                   ret);
        return ret;
    }

    hdl = (SCK_HANDLE *)handle;

    hdl->p = (unsigned char *)malloc(buflen *sizeof(unsigned char));
    if (hdl->p == NULL)
    {
        ret = -2;
        ITCAST_LOG(__FILE__, __LINE__, LogLevel[4], ret, 
                   "func cltSocketSend() err: buflen:%d ", 
                   buflen);
        ITCAST_LOG(__FILE__, __LINE__, LogLevel[4], ret, "func cltSocketSend() err:%d\n  (unsigned char *)malloc(buflen *sizeof(unsigned char) ", ret);
        return ret;
    }
    memcpy(hdl->p, buf, buflen);
    hdl->plen = buflen;

    return 0;
}

//客户端收报文
__declspec(dllexport)
int cltSocketRev(void *handle /*in*/, unsigned char *buf /*in*/, int *buflen /*in out*/)
{
    int        ret = 0;
    SCK_HANDLE *hdl = NULL;

    if (handle==NULL || buf==NULL  ||buflen==NULL)
    {
        ret = -1;
        ITCAST_LOG(__FILE__, __LINE__, LogLevel[4], ret, 
                   "func cltSocketRev() err:%d\n  (handle==NULL || buf==NULL ) ", 
                   ret);
        return ret;
    }
    hdl = (SCK_HANDLE *)handle;

    memcpy(buf, hdl->p, hdl->plen);
    *buflen =  hdl->plen;

    return ret;
}

//客户端释放资源
__declspec(dllexport)
int cltSocketDestory(void *handle/*in*/)
{
    int        ret = 0;
    SCK_HANDLE *hdl = NULL;

    if (handle==NULL )
    {
        ret = -1;
        ITCAST_LOG(__FILE__, __LINE__, LogLevel[4], ret, 
                   "func cltSocketDestory() err:%d\n  (handle==NULL || buf==NULL ) ", 
                   ret);
        return ret;
    }
    hdl = (SCK_HANDLE *)handle;

    if (hdl->p)
    {
        free(hdl->p);
    }
    free(hdl);

    return ret;
}


//-----------------------第二套api函数--------------------------------*/
__declspec(dllexport)
int cltSocketInit2(void **handle)
{
    return cltSocketInit(handle);
}

//客户端发报文
__declspec(dllexport)
int cltSocketSend2(void *handle, unsigned char *buf,  int buflen)
{
    return cltSocketSend(handle, buf, buflen);
}

//客户端收报文
__declspec(dllexport)
int cltSocketRev2(void *handle, unsigned char **buf, int *buflen)
{
    int        ret = 0;
    SCK_HANDLE *hdl = NULL;
    unsigned char        *tmp = NULL;

    if (handle==NULL || buf==NULL  ||buflen==NULL)
    {
        ret = -1;
        ITCAST_LOG(__FILE__, __LINE__, LogLevel[4], ret, 
                   "func cltSocketRev2() err:%d\n  (handle==NULL || buf==NULL ) ", 
                   ret);
        return ret;
    }
    hdl = (SCK_HANDLE *)handle;

    tmp = (unsigned char *)malloc(hdl->plen);
    if (tmp == NULL)
    {
        ret = -2;
        ITCAST_LOG(__FILE__, __LINE__, LogLevel[4], ret, 
                   "func cltSocketRev2() err:%d\n  (malloc err ) ", 
                   ret);
        return ret;
    }

    memcpy(tmp, hdl->p, hdl->plen);
    *buflen =  hdl->plen;

    *buf = tmp; //间接赋值
    return ret;
}

__declspec(dllexport)
int cltSocketRev2_Free(unsigned char **buf)
{
    if (buf == NULL)
    {
        return -1;
    }
    if (*buf != NULL)
    {
        free(*buf);
    }
    *buf = NULL; //*实参的地址  去间接的修改实参的值  重新初始化NULL
    return 0;
}

//客户端释放资源
__declspec(dllexport)
int cltSocketDestory2(void **handle)
{
    SCK_HANDLE *tmp = NULL;
    if (handle==NULL)
    {
        return -1;
    }
    tmp = *handle; 
    if (tmp != NULL)
    {
        if (tmp->p)
        {
            free(tmp->p);
            tmp->p = NULL;
        }
        free(tmp);
    }
    *handle = NULL; //*实参的地址  去间接的修改实参的值  重新初始化NULL

    return 0;
}

socketclientdll.h

socket客户端发送报文接受报文的api接口

#ifndef _INC_Demo01_H
#define _INC_Demo01_H

#ifdef  __cplusplus
extern "C" {
#endif

    //------------------第一套api接口---Begin--------------------------------//
    //客户端初始化 获取handle上下
    int cltSocketInit(void **handle /*out*/); 

    //客户端发报文
    int cltSocketSend(void *handle /*in*/, unsigned char *buf /*in*/,  int buflen /*in*/);

    //客户端收报文
    int cltSocketRev(void *handle /*in*/, unsigned char *buf /*in*/, int *buflen /*in out*/);

    //客户端释放资源
    int cltSocketDestory(void *handle/*in*/);
    //------------------第一套api接口---End-----------------------------------//


    //------------------第二套api接口---Begin--------------------------------//
    int cltSocketInit2(void **handle); 

    //客户端发报文
    int cltSocketSend2(void *handle, unsigned char *buf,  int buflen);
    //客户端收报文
    int cltSocketRev2(void *handle, unsigned char **buf, int *buflen);
    int cltSocketRev2_Free(unsigned char **buf);
    //客户端释放资源

    int cltSocketDestory2(void **handle);
    //------------------第二套api接口---End--------------------------------//

#ifdef  __cplusplus
}
#endif

#endif  /* _INC_Demo01_H */

测试

添加动态库

#define  _CRT_SECURE_NO_WARNINGS 
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "socketclientdll.h"
#include "memwatch.h"

int  main01()
{
    int        ret = 0;
    void    *handle = NULL;

    char buf[128]; /*in*/
    int buflen = 3;/*in*/

    char outbuf[128]; /*in*/
    int outbuflen = 3;/*in*/
    strcpy(buf, "hello, are you ok ?");

    ret = cltSocketInit(&handle /*out*/); 
    if (ret != 0)
    {
        printf("func cltSocketInit() err:%d \n", ret);
        return ret;
    }

    //客户端发报文
    ret =  cltSocketSend(handle /*in*/, buf /*in*/, buflen /*in*/);
    if (ret != 0)
    {
        printf("func cltSocketSend() err:%d \n", ret);
        return ret;
    }

    //客户端收报文
    ret =  cltSocketRev(handle /*in*/, outbuf /*in*/, &outbuflen /*in out*/);
    if (ret != 0)
    {
        printf("func cltSocketRev() err:%d \n", ret);
        return ret;
    }

    //客户端释放资源
     cltSocketDestory(handle/*in*/);

    system("pause");
    return ret ;
}


int main()
{
    int        ret = 0;
    void    *handle = NULL;

    char buf[128]; /*in*/
    int buflen = 3;/*in*/

    //char outbuf[128]; /*in*/ outbuf //常量指针
    //int outbuflen = 3;/*in*/

    char    *pout = NULL;
    int        poutlen = 0;
    strcpy(buf, "hello, are you ok ?");

    ret = cltSocketInit2(&handle); 

    //buflen = -133332;

    //客户端发报文
    ret = cltSocketSend2(handle, buf,  buflen);
    if (ret != 0)
    {
        return ret;
    }

    //客户端收报文
    ret = cltSocketRev2(handle, &pout, &poutlen);  //在动态库里面分配内存了
    if (ret != 0)
    {
        return ret;
    }
    /*
    if (pout != NULL)
    {
        free(pout);
    }
    */

     //避免野指针  把outbuf所指向的内存释放,同时把outbuf变量赋值NULL
    cltSocketRev2_Free(&pout); 

    //ret = cltSocketRev2_Free(&pout);
    //客户端释放资源

    cltSocketDestory2(&handle);
    system("pause");
    return ;
}