Linux socket编程学习初步（3）--客户端向服务器请求文件

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>//read,write
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#include <netdb.h>
#include <sys/fcntl.h>//open
#include <strings.h>

#define SERVER_PORT 12345
#define BUF_SIZE 4096 /* block transfer size */
#define QUEUE_SIZE 10 /* how many client can connect at the same time */

void fatal(char *string)
{
printf("%s\n",string);
exit(1);
}

int main(/*int argc,char * argv[]*/)
{
int s,b,l,fd,sa,bytes,on=1;
char buf[BUF_SIZE]; /*buf for outgoing files*/
struct sockaddr_in channel; /* hold IP address*/

/* Build address structure to bind to socket. */
bzero(&channel,sizeof(channel));
channel.sin_family=AF_INET;
channel.sin_addr.s_addr=htonl(INADDR_ANY);
channel.sin_port=htons(SERVER_PORT);

/* Passive open.Wait for connection. */
s=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);  /* Creat socket */
if(s<0) fatal("socket failed");
setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&on,sizeof(on));
/* use the socket for many time (up word) */
b=bind(s,(struct sockaddr *)&channel,sizeof(channel));
if(b<0) fatal("blind failed");

l=listen(s,QUEUE_SIZE);
if(l<0) fatal("listen failed");

/* Socket is now set up and bound. Wait for connection and process it. */

while(1)
{
sa=accept(s,0,0);
if(sa<0) fatal("accept failed");

recv(sa,buf,BUF_SIZE,0);

/* Get and return the file. */
fd=open(buf,O_RDONLY);
if(fd<0) fatal("open failed");

while(1)
{
bytes=read(fd,buf,BUF_SIZE);
if(bytes<=0) break;
write(sa,buf,bytes);
}

close(fd);
close(sa);
}
return 0;
}

/*
*This page contains a client program that can request a flie from the server program.
*/

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

#define SERVER_PORT 12345
#define BUF_SIZE 4096
#define PATH "/home/fupeng/Desktop/test.txt"
#define DEST_IP "127.0.0.1"

void fatal(char *s)
{
printf("%s\n",s);
exit(1);
}

int main(/*int argc,char * *argv*/)

{
int c,s,bytes;
char buf[BUF_SIZE];   /*buf for incoming files*/
struct sockaddr_in channel;   /* hold IP address*/

//    if (argc!=3)fatal("Usage:client IPaddress file-name");

s=socket(PF_INET,SOCK_STREAM,IPPROTO_TCP);
if(s<0)fatal("socket");

bzero(&channel,sizeof(channel));
channel.sin_family=AF_INET;
channel.sin_port=htons(SERVER_PORT);
if(inet_aton(DEST_IP,&channel.sin_addr)==0)
{

/* use the ASCII ip for the  server's sin_addr. */

fprintf(stderr,"Inet_aton erro\n");
exit(1);
}

c=connect(s,(struct sockaddr *)&channel,sizeof(channel));
if(c<0)fatal("connetct failed");
//    send(s,argv[2],strlen(argv[2]),0);
send(s,PATH,strlen(PATH),0);//BY FUPENG

/* Go get the file and write it to standard output.*/
while(1)
{
bytes=read(s,buf,BUF_SIZE);
if(bytes<=0) exit(0);
write(1,buf,bytes);
}
}