用c语言写一个ftp的客户端代码
时间: 2024-05-12 17:17:04 浏览: 8
好的,以下是一个简单的C语言实现FTP客户端的代码示例:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#define BUF_SIZE 1024
int main(int argc, char *argv[]) {
int sockfd, portno, n;
struct sockaddr_in serv_addr;
struct hostent *server;
char buffer[BUF_SIZE];
if (argc < 3) {
fprintf(stderr,"Usage: %s host port\n", argv[0]);
exit(1);
}
portno = atoi(argv[2]);
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) {
perror("Error opening socket");
exit(1);
}
server = gethostbyname(argv[1]);
if (server == NULL) {
fprintf(stderr,"Error: no such host\n");
exit(1);
}
bzero((char *) &serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
bcopy((char *)server->h_addr, (char *)&serv_addr.sin_addr.s_addr, server->h_length);
serv_addr.sin_port = htons(portno);
if (connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(serv_addr)) < 0) {
perror("Error connecting");
exit(1);
}
while(1) {
bzero(buffer, BUF_SIZE);
printf("Enter command: ");
fgets(buffer, BUF_SIZE, stdin);
n = write(sockfd, buffer, strlen(buffer));
if (n < 0) {
perror("Error writing to socket");
exit(1);
}
if(strncmp(buffer, "quit", 4) == 0) {
break;
}
bzero(buffer, BUF_SIZE);
n = read(sockfd, buffer, BUF_SIZE);
if (n < 0) {
perror("Error reading from socket");
exit(1);
}
printf("%s", buffer);
}
close(sockfd);
return 0;
}
```
这是一个简单的FTP客户端,它通过套接字与FTP服务器通信。用户通过标准输入输入命令,然后程序将命令发送到服务器。然后程序等待服务器的响应并将其打印到标准输出。
注意,这只是一个示例,如果要实现更完整的FTP客户端,需要处理更多的细节,如FTP协议的各种命令和响应,文件传输等等。