linux 实现ftp项目源码（有待写备注）

#define LS      0
#define PWD     1
#define GET     2
#define IFGO    3
#define LLS     4
#define LCD     5
#define CD      6
#define PUT     7
#define QUIT    8
#define DOFILE  9
struct Msg {
    int type;
    char data[1024];        //存放命令和文件数据
    char secondbuf[1024];   //存放文件内容
};

#include<stdio.h>
#include<sys/types.h>
#include<sys/socket.h>
//#include<config.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<stdlib.h>
#include<string.h>
#include "config.h"
#include<sys/stat.h>
#include<fcntl.h>
int get_cmd_type(char *cmd)
{
  if(!strcmp("ls",cmd))   return LS;
  if(!strcmp("quit",cmd))return QUIT;
  if(!strcmp("pwd",cmd)) return PWD;
  if(strstr(cmd,"cd")!=NULL) return CD;
  if(strstr(cmd,"get")!=NULL)return GET;
  if(strstr(cmd,"put")!=NULL)return PUT;
  return 100;
}
char *getdesdir(char *cmsg)
{
  char *p;
  p = strtok(cmsg," ");
  p = strtok(NULL," ");
  return p;
}
void msg_handler(struct Msg msg,int fd)
{
  char databuf[1024]={0};
  char *file = NULL;
  int fdfile;
  printf("cmd:%s\n",msg.data);
  int ret = get_cmd_type(msg.data);
  switch(ret){
    case LS:
    case PWD:
      msg.type = 0;
      FILE *r = popen(msg.data,"r");
      fread(msg.data,sizeof(msg.data),1,r);
      write(fd,&msg,sizeof(msg));
      break;
    case CD:
      msg.type = 1;
      char *dir = getdesdir(msg.data);
      printf("dir:%s\n",dir);
      chdir(dir);
      break;
    case GET:
      file = getdesdir(msg.data);
      if(access(file,F_OK)==-1){
        strcpy(msg.data,"No this File!");
        write(fd,&msg,sizeof(msg));
      }else{
        msg.type = DOFILE;
        fdfile = open(file,O_RDWR);
        read(fdfile,databuf,sizeof(databuf));
        close(fdfile);
        strcpy(msg.data,databuf);
        write(fd,&msg,sizeof(msg));
      }
      break;
    case PUT: 
      fdfile = open(getdesdir(msg.data),O_RDWR|O_CREAT,0666);
      write(fdfile, msg.secondbuf, strlen(msg.secondbuf));
      close(fdfile);
      break;
    case QUIT:
      printf("client quit!\n");
      exit(-1);
  }
}
int main(int argc,char **argv)
{
  int s_fd;
  int c_fd;
  int n_read;
  char readbuf[128];
  struct sockaddr_in s_addr;
  struct sockaddr_in c_addr;
  struct Msg msg;
  if(argc !=3){
    printf("param is not good\n");
    exit(-1);
  }
  memset(&s_addr,0,sizeof(struct sockaddr_in));
  memset(&c_addr,0,sizeof(struct sockaddr_in));
  s_fd = socket(AF_INET,SOCK_STREAM,0);
  if(s_fd == -1){
    perror("socket");
    exit(-1);
  }
  s_addr.sin_family = AF_INET;
  s_addr.sin_port = htons(atoi(argv[2]));
  inet_aton(argv[1],&s_addr.sin_addr);
  bind(s_fd,(struct sockaddr *)&s_addr,sizeof(struct sockaddr_in));
  listen(s_fd,10);
  int clen = sizeof(struct sockaddr_in);
  while(1){
    c_fd = accept(s_fd,(struct sockaddr *)&c_addr,&clen);
    if(c_fd ==-1){
      perror("accept");
    }
    printf("get connect: %s\n",inet_ntoa(c_addr.sin_addr));
    if(fork()==0){
      while(1){
        memset(msg.data,0,sizeof(msg.data));
        n_read = read(c_fd,&msg,sizeof(msg));
        if(n_read == 0){
          printf("client out\n");
          break;
        }else if(n_read > 0){
          msg_handler(msg,c_fd);
        }
      }
    }
  }
  close(c_fd);
  close(s_fd);
  return 0;
}

#include<stdio.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<stdlib.h>
#include<string.h>
#include"config.h"
//#include<sys/stat.h>
#include<fcntl.h>
char * getdir(char *cmd)
{
  char *p;
  p = strtok(cmd," ");
  p = strtok(NULL," ");
  return p;
}
int get_cmd_type(char *cmd)
{
  if(strstr(cmd,"lcd")) return LCD;
  if(!strcmp("quit",cmd)) return QUIT;
        if(!strcmp("ls",cmd))   return LS;
  if(!strcmp("lls",cmd)) return LLS;
        if(!strcmp("pwd",cmd)) return LS;
        if(strstr(cmd,"cd")!=NULL) return CD;
        if(strstr(cmd,"get")!=NULL)return GET;
        if(strstr(cmd,"put")!=NULL)return PUT;
        return -1;
}
int cmd_handler(struct Msg msg,int fd)
{
  char *dir = NULL;
  char buf[32];
  int ret;
  int filefd;
  ret = get_cmd_type(msg.data);
  switch(ret){
    case LS:
    case CD:
    case PWD:
      msg.type = 0;
      write(fd,&msg,sizeof(msg));
      break;
    case GET:
      msg.type = 2;
      write(fd,&msg,sizeof(msg));
      break;
    case PUT:
      strcpy(buf,msg.data);
      dir = getdir(buf);
      if(access(dir,F_OK)==-1){
        printf("%s not exsit\n",dir);
      }else{
        filefd = open(dir,O_RDWR);
        read(filefd,msg.secondbuf,sizeof(msg.secondbuf));
        close(filefd);
        write(fd,&msg,sizeof(msg));
      }
      break;
    case LLS:
      system("ls");
      break;
    case LCD:
      dir = getdir(msg.data);
      chdir(dir);
      break;
    case QUIT:
      strcpy(msg.data,"quit");
      write(fd,&msg,sizeof(msg));
      close(fd);
      exit(-1);
  }
  return ret;
}
void handler_server_message(int c_fd,struct Msg msg)
{
  int n_read;
  struct Msg msgget;
  int newfilefd;
  n_read = read(c_fd,&msgget,sizeof(msgget));
  if(n_read == 0){
    printf("server is out,quit\n");
    exit(-1);
  }
  else if(msgget.type == DOFILE){
    char *p = getdir(msg.data);
    newfilefd = open(p,O_RDWR|O_CREAT,0600);
    write(newfilefd,msgget.data,strlen(msgget.data));
    putchar('>');
    fflush(stdout);
  }
  else {
    printf("------------------------------------\n");
    printf("\n%s\n",msgget.data);
                printf("------------------------------------\n");
    putchar('>');
    fflush(stdout);
  }
}
int main(int argc,char **argv)
{
  int c_fd;
  struct sockaddr_in c_addr;
  struct Msg msg;
  memset(&c_addr,0,sizeof(struct sockaddr_in));
  if(argc != 3){
    printf("param is not good\n");
    exit(-1);
  }
  c_fd = socket(AF_INET,SOCK_STREAM,0);
  if(c_fd == -1){
    perror("socket");
    exit(-1);
  }
  c_addr.sin_family = AF_INET;
  c_addr.sin_port = htons(atoi(argv[2]));
  inet_aton(argv[1],&c_addr.sin_addr);
  if(connect(c_fd,(struct sockaddr *)&c_addr,sizeof(struct sockaddr))== -1){
    perror("connect");
    exit(-1);
  }
  printf("connect ...\n");
  int mark = 0;
  while(1){
    memset(msg.data,0,sizeof(msg.data));
    if(mark == 0) printf(">");
    gets(msg.data);
    if(strlen(msg.data)==0){
      if(mark == 1){
        printf(">");
      }
      continue;
    }
    mark =1;
    int ret = cmd_handler(msg,c_fd);
    if(ret > IFGO){
      putchar('>');
      fflush(stdout);
      continue;
    }
    if(ret ==-1){
      printf("command not \n");
      printf(">");
      fflush(stdout);
      continue;
    }
    handler_server_message(c_fd,msg);
  }
  return 0;
}