通过Linux socket读取Linux服务器上的文件

从Linux客户机上读取另一台Linux服务器上指定目录下的文件，服务器端代码和客户端代码实现如下：

#include <string>
#include <string.h>
#include <stdio.h>
#include <sys/socket.h>
#include <unistd.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <time.h>
#include <arpa/inet.h>

#define SERVER_PORT 20000 // define the defualt connect port id
#define LENGTH_OF_LISTEN_QUEUE 10 //length of listen queue in server
#define BUFFER_SIZE 255
#define LINE_LEN 60 // in the file, define one line's length
#define WELCOME_MESSAGE "welcome to connect the server. "

int main(int argc, char **argv)
{
int servfd,clifd;
char s[LINE_LEN];
struct sockaddr_in servaddr,cliaddr;

if ((servfd = socket(AF_INET,SOCK_STREAM,0)) < 0){
printf("create socket error!\n");
exit(1);
}

bzero(&servaddr,sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(SERVER_PORT);
servaddr.sin_addr.s_addr = htons(INADDR_ANY);

if (bind(servfd,(struct sockaddr*)&servaddr,sizeof(servaddr))<0){
printf("bind to port %d failure!\n",SERVER_PORT);
exit(1);
}

if (listen(servfd,LENGTH_OF_LISTEN_QUEUE) < 0){
printf("call listen failure!\n");
exit(1);
}

while(1){ //server loop will nerver exit unless any body kill the process
char buf[BUFFER_SIZE];
long timestamp;
socklen_t length = sizeof(cliaddr);

clifd = accept(servfd,(struct sockaddr*)&cliaddr,&length);
if (clifd < 0){
printf("error comes when call accept!\n");
break;
}

strcpy(buf,WELCOME_MESSAGE);

printf("from client,IP:%s,Port:%d\n",inet_ntoa(cliaddr.sin_addr),ntohs(cliaddr.sin_port));
timestamp = time(NULL);
strcat(buf,"timestamp in server:");
strcat(buf,ctime(&timestamp));

// read file rule.txt
FILE* stream_src = fopen( "rule.txt", "r " );
if( stream_src=../../=NULL ){
printf("the file rule.txt is not opened correctly!\n");
return 1;
}

while( fgets(s,sizeof(s),stream_src) ){ // 按行读取
printf( "%s", s );
strcat( buf,s );
}

// send file's content to client
send(clifd,buf,BUFFER_SIZE,0);
close(clifd);
}

close(servfd);
return 0;
}

#include <string>
#include <string.h>
#include <stdio.h>
#include <sys/socket.h>
#include <unistd.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <arpa/inet.h>

#define SERVER_PORT 20000 // define the defualt connect port id
#define CLIENT_PORT ((20001 rand())e536) // define the defualt client port as a random port
#define BUFFER_SIZE 255
#define REUQEST_MESSAGE "welcome to connect the server.\n"

void usage(char *name)
{
printf("usage: %s IpAddr\n",name);
}

int main(int argc, char **argv)
{
int servfd,clifd,length = 0;
struct sockaddr_in servaddr,cliaddr;
socklen_t socklen = sizeof(servaddr);
char buf[BUFFER_SIZE];

if (argc < 2){
usage(argv[0]);
exit(1);
}

if ((clifd = socket(AF_INET,SOCK_STREAM,0)) < 0){
printf("create socket error!\n");
exit(1);
}

srand(time(NULL));//initialize random generator
bzero(&cliaddr,sizeof(cliaddr));
cliaddr.sin_family = AF_INET;
cliaddr.sin_port = htons(CLIENT_PORT);
cliaddr.sin_addr.s_addr = htons(INADDR_ANY);

bzero(&servaddr,sizeof(servaddr));
servaddr.sin_family = AF_INET;
inet_aton(argv[1],&servaddr.sin_addr);
servaddr.sin_port = htons(SERVER_PORT);
//servaddr.sin_addr.s_addr = htons(INADDR_ANY);

if (bind(clifd,(struct sockaddr*)&cliaddr,sizeof(cliaddr))<0){
printf("bind to port %d failure!\n",CLIENT_PORT);
exit(1);
}

if (connect(clifd,(struct sockaddr*)&servaddr, socklen) < 0){
printf("can't connect to %s!\n",argv[1]);
exit(1);
}

length = recv(clifd,buf,BUFFER_SIZE,0);
if (length < 0){
printf("error comes when recieve data from server %s!",argv[1]);
exit(1);
}

printf("from server %s :\n\t%s ",argv[1],buf);

close(clifd);
return 0;
}