Linux C + + TCP socket transfer file or picture instance

Environment: Linux language: C + + Communication Mode: TCP

　　The following uses the TCP protocol to write a simple server, the client, where the server side has been listening to the local port number No. 6666. If a connection request is received, the request is received and the message is received from the client, and the client establishes a connection to the server side. After the connection is established, read the contents of the file (/root/workspace/socket-picture/ bizhi.jpg), sent to the server side, the server side of the new New1.jpg file, the received file content is saved to new1.jpg, new1.jpg in the current directory;

Server.cpp

1#include <stdio.h>2#include <stdlib.h>3#include <string.h>4#include <errno.h>5#include <sys/types.h>6#include <sys/socket.h>7#include <netinet/inch.h>8#include <unistd.h>9 Ten #defineMAXLINE 4096 One  A intMainintargcChar**argv) { -     intlistenfd, CONNFD; -     structsockaddr_in servaddr; the     Charbuff[4096]; -FILE *FP; -     intN; -  +     if(LISTENFD = socket (af_inet, Sock_stream,0)) == -1 ){ -printf"Create socket Error:%s (errno:%d) \ n", Strerror (errno), errno); +         return 0; A     } atprintf"----init socket----\ n"); -  -memset (&AMP;SERVADDR,0,sizeof(SERVADDR)); -servaddr.sin_family =af_inet; -SERVADDR.SIN_ADDR.S_ADDR =htonl (inaddr_any); -Servaddr.sin_port = htons (6666); in     //to set up ports for reuse -     intcontain; toSetSockOpt (Listenfd,sol_socket, SO_REUSEADDR, &contain,sizeof(int)); +  -     if(Bind (LISTENFD, (structsockaddr*) &servaddr,sizeof(SERVADDR)) == -1){ theprintf"bind socket Error:%s (errno:%d) \ n", Strerror (errno), errno); *         return 0; $     }Panax Notoginsengprintf"----bind sucess----\ n"); -  the     if(Listen (LISTENFD,Ten) == -1){ +printf"Listen socket Error:%s (errno:%d) \ n", Strerror (errno), errno); A         return 0; the     } +     if(fp = fopen ("new1.jpg","AB") ) ==NULL) -     { $printf"file.\n"); $ Close (LISTENFD); -Exit1); -     } the  -printf"======waiting for client ' s request======\n");Wuyi      while(1){ the         structsockaddr_in client_addr; -Socklen_t size=sizeof(CLIENT_ADDR); Wu         if(CONNFD = Accept (LISTENFD, (structsockaddr*) &client_addr, &size)) = =-1){ -printf"Accept Socket Error:%s (errno:%d)", Strerror (errno), errno); About             Continue; $         } -          while(1){ -n =Read (CONNFD, buff, MAXLINE); -             if(n = =0) A                  Break; +Fwrite (Buff,1, N, FP); the         } -Buff[n] =' /'; $printf"recv msg from client:%s\n", buff); the Close (CONNFD); the fclose (FP); the     } the Close (LISTENFD); -     return 0; in}

Client.cpp

1#include <stdio.h>2#include <errno.h>3#include <string.h>4#include <netdb.h>5#include <sys/types.h>6#include <netinet/inch.h>7#include <sys/socket.h>8#include <stdlib.h>9#include <unistd.h>Ten#include <arpa/inet.h> One#include <netdb.h> A #defineMAXLINE 4096 -  - intMainintargcChar**argv) { the     intsockfd, Len; -     CharBuffer[maxline]; -     structsockaddr_in servaddr; -FILE *Fq; +  -     if(ARGC! =2){ +printf"usage:./client <ipaddress>\n"); A         return 0; at     } -  -     if(SOCKFD = socket (af_inet, Sock_stream,0)) <0){ -printf"Create socket Error:%s (errno:%d) \ n", Strerror (errno), errno); -         return 0; -     } in  -memset (&AMP;SERVADDR,0,sizeof(SERVADDR)); toservaddr.sin_family =af_inet; +Servaddr.sin_port = htons (6666); -     if(Inet_pton (Af_inet, argv[1], &servaddr.sin_addr) <=0){ theprintf"Inet_pton error for%s\n", argv[1]); *         return 0; $     }Panax Notoginseng  -     if(Connect (SOCKFD,structsockaddr*) &servaddr,sizeof(SERVADDR)) <0){ theprintf"Connect Error:%s (errno:%d) \ n", Strerror (errno), errno); +         return 0; A     } the     if(Fq = fopen ("/root/workspace/socket-picture/bizhi.jpg","RB") ) ==NULL) { +printf"File open.\n"); - Close (SOCKFD); $Exit1); $     } -  -Bzero (Buffer,sizeof(buffer)); the      while(!feof (FQ)) { -Len = fread (buffer,1,sizeof(buffer), FQ);Wuyi         if(Len! =Write (sockfd, buffer, Len)) { theprintf"write.\n"); -              Break; Wu         } -     } About Close (SOCKFD); $ fclose (FQ); -  -     return 0; -}

Makefile

1 All:server Client2 SERVER:SERVER.O3g++-G-o server server.o4 CLIENT:CLIENT.O5g++-G-o client client.o6 Server.o:server.cpp7g++-G-C Server.cpp8 Client.o:client.cpp9g++-G-C client.cppTen Clean:all OneRM All

after the make command is executed, the server and client two executables are generated. Open two terminal Windows respectively, one executes the./server command, one executes the./client 127.0.0.1 command, which indicates that the 6666 port of the machine is attached, executing the./server command to execute first. After executing the./client 127.0.0.1 command, client clients exit directly after execution, and you can see the terminal window of the server output "Recv msg from client:". Open the current directory (refers to the directory where the executable file server is located), you can see the new1.jpg file has been generated, double-click Open, the contents of the file is not lost.

Linux C + + TCP socket transfer file or picture instance