最近在写Linux网络方面的demo,用TCP实现了一个简单的传输文件程序，适用于网卡设备及TCP/IP协议栈及网络环境测试时使用。用法容易，代码简洁，已经测试成功。其功能是使用TCP协议从client端向server端传输文件，用法如下:

编译：

client:gcc -o client client.c

server:gcc -o server server.c

运行：

client端：./client <端口号> <上传文件名>

server端：./server <端口号> <保存为文件名>

其中，server端先运行，client端与server端的端口号必须一致并且不能与已知端口冲突（例如8888即可）

server端代码:server.c

#include
#include
#include
#include
#include
#include
#include
#include
#include

#define MAXLINE 1024

void usage(char *command)
{
printf("usage :%s portnum filename\n", command);
exit(0);
}
int main(int argc,char **argv)
{
struct sockaddr_in serv_addr;
struct sockaddr_in clie_addr;
char buf[MAXLINE];
int sock_id;
int link_id;
int recv_len;
int write_leng;
int clie_addr_len;
FILE *fp;

if (argc != 3) {
usage(argv[0]);
}
if ((fp = fopen(argv[2], "w")) == NULL) {
perror("Open file failed\n");
exit(0);
}
if ((sock_id = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
perror("Create socket failed\n");
exit(0);
}
/*fill the server sockaddr_in struct commented by guoqingbo*/
memset(&serv_addr, 0, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_port = htons(atoi(argv[1]));
serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);

if (bind(sock_id, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0 ) {
perror("Bind socket failed\n");
exit(0);
}

if (-1 == listen(sock_id, 10)) {
perror("Listen socket failed\n");
exit(0);
}
/* server part commented by guoqingbo*/
while (1) {
clie_addr_len = sizeof(clie_addr);
link_id = accept(sock_id, (struct sockaddr *)&clie_addr, &clie_addr_len);
if (-1 == link_id) {
perror("Accept socket failed\n");
exit(0);
}
bzero(buf, MAXLINE);
while (recv_len = recv(link_id, buf, MAXLINE, 0)) {
/* receiver data part commented by guoqingbo*/
if(recv_len < 0) {
printf("Recieve Data From Server Failed!\n");
break;
}
printf("#");
write_leng = fwrite(buf, sizeof(char), recv_len, fp);
if (write_leng < recv_len) {
printf("Write file failed\n");
break;
}
bzero(buf,MAXLINE);
}
printf("\nFinish Recieve\n");
fclose(fp);
close(link_id);
}
close(sock_id);
return 0;
}