FTP服务器与客户端实现

服务器端代码解析

在本节中，我们将重点分析服务器端的实现细节。服务器端代码主要包含以下几个部分：

1. 包含头文件

#include 
   
    #include 
    
     #include 
     
      #include 
      
       #include 
       
        #include 
        
         #include 
         
          #include 
          
           #include 
           
            #include 
            
             #include "config.h"

2. 命令处理函数

int option_cmd(char *cmd){    if (strcmp(cmd, "ls") == 0) return LS;    if (strcmp(cmd, "pwd") == 0) return PWD;    if (strcmp(cmd, "quit") == 0) return QUIT;    if (strstr(cmd, "cd") != NULL) return CD;    if (strstr(cmd, "get") != NULL) return GET;    if (strstr(cmd, "put") != NULL) return PUT;}

3. 获取目录函数

char *GetDir(char *dircmd){    char *p;    p = strtok(dircmd, " ");    p = strtok(NULL, " ");    return p;}

4. 命令执行函数

void command(struct Message msg, int fd){    char cmdbuf[1024] = {0};    char *file = NULL;    int file_fd;    printf("the client cmd is: %s\n", msg.data);    int cmd = option_cmd(msg.data);    switch(cmd)    {        case LS:            msg.type = 0;            FILE *p = popen(msg.data, "r");            fread(msg.data, sizeof(msg.data), 1, p);            write(fd, &msg, sizeof(msg));            break;        case PWD:            msg.type = 0;            write(fd, &msg, sizeof(msg));            break;        case QUIT:            printf("the client die out\n");            exit(-1);            break;        case CD:            msg.type = 1;            char *dir = GetDir(msg.data);            break;        case PUT:            file_fd = open(GetDir(msg.data), O_CREAT | O_RDWR, 0666);            write(file_fd, msg.msgbuf, strlen(msg.msgbuf));            close(file_fd);            break;        case GET:            file = GetDir(msg.data);            if (access(file, F_OK) == -1)            {                strcpy(msg.data, "the file don't exit");                write(fd, &msg, sizeof(msg));            }            else            {                msg.type = DOFILE;                file_fd = open(file, O_RDWR);                read(file_fd, cmdbuf, sizeof(cmdbuf));                close(file_fd);                strcpy(msg.data, cmdbuf);                write(fd, &msg, sizeof(msg));            }            break;        default:            break;    }}

客户端代码解析

客户端代码的实现主要包含以下几个部分：

1. 包含头文件

#include 
   
    #include 
    
     #include 
     
      #include 
      
       #include 
       
        #include 
        
         #include 
         
          #include 
          
           #include 
           
            #include 
            
             #include "config.h"

2. 命令处理函数

int option_cmd(char *cmd){    if (strcmp(cmd, "ls") == 0) return LS;    if (strcmp(cmd, "pwd") == 0) return PWD;    if (strcmp(cmd, "lls") == 0) return LLS;    if (strcmp(cmd, "quit") == 0) return QUIT;    if (strstr(cmd, "get") != NULL) return GET;    if (strstr(cmd, "put") != NULL) return PUT;    if (strcmp(cmd, "cd") == 0) return CD;    if (strstr(cmd, "lcd") != NULL) return LCD;    return -1;}

3. 获取目录函数

char *GetDir(char *cmd){    char *p;    p = strtok(cmd, " ");    p = strtok(NULL, " ");    return p;}

4. 命令执行函数

int option_cmd_handle(struct Message msg, int fd){    char buf[128] = {0};    char cmdbuf[1024];    int CMD;    strncpy(buf, msg.data, sizeof(msg.data));    char *dir = GetDir(buf);    CMD = option_cmd(buf);    switch(CMD)    {        case LS:        case PWD:            msg.type = 0;            write(fd, &msg, sizeof(msg));            break;        case CD:            msg.type = 1;            write(fd, &msg, sizeof(msg));            break;        case LCD:            chdir(dir);            break;        case QUIT:            strcpy(msg.data, "quit");            write(fd, &msg, sizeof(msg));            close(fd);            exit(-1);            break;        case LLS:            system("ls");            break;        case GET:            write(fd, &msg, sizeof(msg));            break;        case PUT:            strcpy(cmdbuf, msg.data);            if (access(dir, F_OK) == -1)            {                printf("the %s file is no have\n", dir);            }            else            {                file_fd = open(dir, O_RDWR);                read(file_fd, msg.msgbuf, sizeof(msg.msgbuf));                close(file_fd);                write(fd, &msg, sizeof(msg));            }            break;        default:            break;    }    return CMD;}