脚本协议怎么写(编写数据通信协议代码的小技巧)

下面是好好范文网小编收集整理的脚本协议怎么写(编写数据通信协议代码的小技巧)，仅供参考，欢迎大家阅读！

1.有时候我们需要制定协议与其他设备、后台服务器通信，为了代码后期的易维护性，就不用以下这种方式，因为如果没有协议文档对照这里面代码就给人感觉有点魔幻。

char send_data[64]={0};send_data[0]=0x49;send_data[1]=0x52;....send_data[63]=或者这样，这样子在修改协议代码还好改一点，但脱离了协议，比较难理解这些赋值的实际含义int index=0；send_data[index]=0x49;send_data[index++]=0x52;index+= flag=0x53；send_data[index]=flag;....send_data[index]=0x52;

有时候还需要小端转大端，上传服务器，如果用这种方法赋值，没有协议文档接手这份代码的人就有点疑惑。实际上，上面的方法运行的速度是最快的，但就是不便维护。

2.我们可以将协议头、数据、协议尾分开定义，方便后期协议修改，代码作少量改动。

如果协议允许，可以尝试字节对齐，如4字节对齐、8字节对齐，即short byte等都用对齐占4字节，牺牲性能换取代码的易维护性。

这里就用简单的办法实现，较为容易维护代码，但代码比较冗余,实现转换为大端字节通信。

V1：

myprotocol.h

#ifndef _MYPROTOCOL_H_#define _MYPROTOCOL_H_#ifdef __cplusplusextern#endiftypedef struct _my_msg_head{    char msg_head[2];    char version[2];    char msg_num[4];    char reply_num[4];    char utc_time[8];    char data_len[4];}my_msg_head;typedef struct _my_msg_data{    char role_id[8];    char move_type[4];    char distance[4];    char speed[2];}my_msg_data;typedef struct _my_msg_tail{    char msg_tail[2];}my_msg_tail;//大端字节序列void set_short_value_b(char* out,shortin); set_int_value_b(char* out,intin); set_float_value_b(char* out,floatin); set_double_value_b(char* out,doublein); set_long_long_value_b(char* out,); set_ushort_value_b(char* out,unsigned shortin); set_uint_value_b(char* out,unsigned intin); set_ulong_long_value_b(char* out,unsigned ); make_frame_data(my_msg_head *,my_msg_data*,my_msg_tail*,char *in,int in_size);#ifdef __cplusplus}#endif#endif

myprotocol.c

#include <stdio.h>#include <string.h>#include "myprotocol.h"void set_short_value_b(char* out,shortin){    out[0]=(char)((in>>8)&0xff);    out[1]=(char)(in& set_int_value_b(char* out,intin){    out[0]=(char)((in>>24)&0xff);    out[1]=(char)((in>>16)&0xff);    out[2]=(char)((in>>8)&0xff);    out[3]=(char)(in& set_float_value_b(char* out,floatin){    char *p=(char*)(&in);    for(int i=0;i<4;i++)    {        out[i]=p[4-i-1];    }}void set_double_value_b(char* out,doublein){    char *p=(char*)(&in);    for(int i=0;i<8;i++)    {        out[i]=p[8-i-1];    }}void set_long_long_value_b(char* out,){    char *p=(char*)(&in);    for(int i=0;i<8;i++)    {        out[i]=p[8-i-1];    }}void set_ushort_value_b(char* out,unsigned shortin){    char *p=(char*)(&in);    for(int i=0;i<2;i++)    {        out[i]=p[2-i-1];    }}void set_uint_value_b(char* out,unsigned intin){    char *p=(char*)(&in);    for(int i=0;i<4;i++)    {        out[i]=p[4-i-1];    }}void set_ulong_long_value_b(char* out,unsigned ){    char *p=(char*)(&in);    for(int i=0;i<8;i++)    {        out[i]=p[8-i-1];    }}int make_frame_data(my_msg_head *p_head,my_msg_data* p_data,my_msg_tail* p_tail,char *in,int in_size){    int head_len=sizeof(my_msg_head);    int data_len=sizeof(my_msg_data);    int tail_len=sizeof(my_msg_tail);    int total_len=head_len+ data_len+tail_len;    if(in_size<total_len)    {        return -1;    }    memcpy(in,p_head,head_len);    memcpy(in+head_len,p_data,data_len);    memcpy(in+head_len+data_len,p_tail,tail_len);    return total_len;}

main.c

#include <stdio.h>#include <time.h>#include <unistd.h>#include <string.h>#include "myprotocol.h"void printData(char *data,int len){    printf("data :n");    for(int i=0;i<len;i++)    {        printf(,(unsigned char)data[i]);        if(i>0&&((i+1)%10==0))        {            printf();        }    }    printf("n>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>n");}unsigned longlong getTime_ms(){    struct timespec time1 = {0, 0};     clock_gettime(CLOCK_REALTIME, &time1);       unsigned longlong ret=((unsigned longlong)time1.tv_sec)*1000+((unsigned longlong)time1.tv_nsec)/1000/1000+8*60*60*1000;    printData((char *)&ret,8);    return ret;}int main(int argc, char **argv){    char send_data[512]={0};    my_msg_head m_head;    my_msg_data m_data;    my_msg_tail m_tail;    memset(&m_head,0,sizeof(m_head));    memset(&m_data,0,sizeof(m_data));    memset(&m_tail,0,sizeof(m_tail));    m_head.msg_head[0]=0x05;    m_head.msg_head[1]=0x49;    m_head.version[1]=0x01;    m_head.version[0]=0x00;    set_int_value_b(m_head.msg_num,0x1002);    set_int_value_b(m_head.reply_num,0x20001);    set_ulong_long_value_b(m_head.utc_time,getTime_ms());    set_int_value_b(m_head.data_len,sizeof(my_msg_data));    set_ulong_long_value_b(m_data.role_id,0x1234);    set_uint_value_b(m_data.move_type,(unsigned int)0x56789);    set_uint_value_b(m_data.distance,0x1234);    set_ushort_value_b(m_data.speed,0x5678);    m_tail.msg_tail[0]=0x05;    m_tail.msg_tail[1]= send_len=make_frame_data(&m_head,&m_data,&m_tail,send_data,sizeof(send_data));    printData(send_data,send_len);    /*    小端:        49 05 01 00 02 10 00 00 01 00          02 00 b6 04 9f b0 76 01 00 00          12 00 00 00 34 12 00 00 00 00         00 00 89 67 05 00 34 12 00 00        78 56 49 05     大端：        05 49 00 01 00 00 10 02 00 02         00 01 00 00 01 76 b0 9f 04 b6         00 00 00 12 00 00 00 00 00 00         12 34 00 05 67 89 00 00 12 34         56 78 05 49    */}

V2

加入了字节长度判断，代码更加冗余了

myprotocol.h

#ifndef _MYPROTOCOL_H_#define _MYPROTOCOL_H_#ifdef __cplusplusextern#endiftypedef struct _my_msg_head{    char msg_head[2];    char version[2];    char msg_num[4];    char reply_num[4];    char utc_time[8];    char data_len[4];}my_msg_head;typedef struct _my_msg_data{    char role_id[8];    char move_type[4];    char distance[4];    char speed[2];}my_msg_data;typedef struct _my_msg_tail{    char msg_tail[2];}my_msg_tail;//大端字节序列void set_short_value_b(char* out,shortin,int len); set_int_value_b(char* out,intin,int len); set_float_value_b(char* out,floatin,int len); set_double_value_b(char* out,doublein,int len); set_long_long_value_b(char* out,,int len); set_ushort_value_b(char* out,unsigned shortin,int len); set_uint_value_b(char* out,unsigned intin,int len); set_ulong_long_value_b(char* out,unsigned ,int len); make_frame_data(my_msg_head *,my_msg_data*,my_msg_tail*,char *in,int in_size);#ifdef __cplusplus}#endif#endif

myprotocol.c

#include <stdio.h>#include <string.h>#include "myprotocol.h"void set_short_value_b(char *out, shortin, int len){    if (len != sizeof(short))        return;    out[0] = (char)((in >> 8) & 0xff);    out[1] = (char)(in &  set_int_value_b(char *out, intin, int len){    if (len != sizeof(int))        return;    out[0] = (char)((in >> 24) & 0xff);    out[1] = (char)((in >> 16) & 0xff);    out[2] = (char)((in >> 8) & 0xff);    out[3] = (char)(in &  set_float_value_b(char *out, floatin, int len){    if (len != sizeof(float))        return;    char *p = (char *)(&in);    for (int i = 0; i < 4; i++)    {        out[i] = p[4 - i - 1];    }}void set_double_value_b(char *out, doublein, int len){    if (len != sizeof(double))        return;    char *p = (char *)(&in);    for (int i = 0; i < 8; i++)    {        out[i] = p[8 - i - 1];    }}void set_long_long_value_b(char *out, , int len){    if (len != sizeof(longlong))        return;    char *p = (char *)(&in);    for (int i = 0; i < 8; i++)    {        out[i] = p[8 - i - 1];    }}void set_ushort_value_b(char *out, unsigned shortin, int len){    if (len != sizeof(unsigned short))        return;    char *p = (char *)(&in);    for (int i = 0; i < 2; i++)    {        out[i] = p[2 - i - 1];    }}void set_uint_value_b(char *out, unsigned intin, int len){    if (len != sizeof(unsigned int))        return;    char *p = (char *)(&in);    for (int i = 0; i < 4; i++)    {        out[i] = p[4 - i - 1];    }}void set_ulong_long_value_b(char *out, unsigned , int len){    if (len != sizeof(unsigned longlong))        return;    char *p = (char *)(&in);    for (int i = 0; i < 8; i++)    {        out[i] = p[8 - i - 1];    }}int make_frame_data(my_msg_head *p_head, my_msg_data *p_data, my_msg_tail *p_tail, char *in, int in_size){    int head_len = sizeof(my_msg_head);    int data_len = sizeof(my_msg_data);    int tail_len = sizeof(my_msg_tail);    int total_len = head_len + data_len + tail_len;    if (in_size < total_len)    {        return -1;    }    memcpy(in, p_head, head_len);    memcpy(in + head_len, p_data, data_len);    memcpy(in + head_len + data_len, p_tail, tail_len);    return total_len;}

main.c

#include <stdio.h>#include <time.h>#include <unistd.h>#include <string.h>#include "myprotocol.h"void printData(char *data,int len){    printf("data :n");    for(int i=0;i<len;i++)    {        printf(,(unsigned char)data[i]);        if(i>0&&((i+1)%10==0))        {            printf();        }    }    printf("n>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>n");}unsigned longlong getTime_ms(){    struct timespec time1 = {0, 0};     clock_gettime(CLOCK_REALTIME, &time1);       unsigned longlong ret=((unsigned longlong)time1.tv_sec)*1000+((unsigned longlong)time1.tv_nsec)/1000/1000+8*60*60*1000;    printData((char *)&ret,8);    return ret;}int main(int argc, char **argv){    char send_data[512]={0};    my_msg_head m_head;    my_msg_data m_data;    my_msg_tail m_tail;    memset(&m_head,0,sizeof(m_head));    memset(&m_data,0,sizeof(m_data));    memset(&m_tail,0,sizeof(m_tail));    m_head.msg_head[0]=0x05;    m_head.msg_head[1]=0x49;    m_head.version[1]=0x01;    m_head.version[0]=0x00;    set_int_value_b(m_head.msg_num,0x1002,sizeof(m_head.msg_num));    set_int_value_b(m_head.reply_num,0x20001,sizeof(m_head.reply_num));    set_ulong_long_value_b(m_head.utc_time,getTime_ms(),sizeof(m_head.utc_time));    set_int_value_b(m_head.data_len,sizeof(my_msg_data),sizeof(m_head.data_len));    set_ulong_long_value_b(m_data.role_id,0x1234,sizeof(m_data.role_id));    set_uint_value_b(m_data.move_type,(unsigned int)0x56789,sizeof(m_data.move_type));    set_uint_value_b(m_data.distance,0x1234,sizeof(m_data.distance));    set_ushort_value_b(m_data.speed,0x5678,sizeof(m_data.speed));    m_tail.msg_tail[0]=0x05;    m_tail.msg_tail[1]= send_len=make_frame_data(&m_head,&m_data,&m_tail,send_data,sizeof(send_data));    printData(send_data,send_len);    /*    小端:        49 05 01 00 02 10 00 00 01 00          02 00 b6 04 9f b0 76 01 00 00          12 00 00 00 34 12 00 00 00 00         00 00 89 67 05 00 34 12 00 00        78 56 49 05     大端：        05 49 00 01 00 00 10 02 00 02         00 01 00 00 01 76 b0 9f 04 b6         00 00 00 12 00 00 00 00 00 00         12 34 00 05 67 89 00 00 12 34         56 78 05 49    */}