1. 如何运用socket网络编程实现上位机和下位机之间通过wifi进行通信
用wifi还是有线那是系统的事，你要做的就是保证上位机下位机能加入同一网络就可以了（或者上位机用公网地址，下位机能经过局域网访问互联网）
2. linux下socket 网络编程(客户端向服务器端发送文件) 求源代码 大哥大姐帮帮忙 。。谢谢
server:
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <syslog.h>
#include <sys/time.h>
#include <string.h>
#include <fcntl.h>
#include <sys/wait.h>
#define MAXDATASIZE 1024
#define SERVPORT 19999
#define BACKLOG 10
int SendFileToServ(const char *path, const char *FileName, const char *ip)
{
#define PORT 20002
int sockfd;
int recvbytes;
char buf[MAXDATASIZE];
char send_str[MAXDATASIZE];
char filepath[128] = {0};
struct sockaddr_in serv_addr;
FILE *fp;
sprintf(filepath, "%s%s", path, FileName);
if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)
{
perror("socket");
return 1;
}
bzero(&serv_addr,sizeof(struct sockaddr_in));
serv_addr.sin_family=AF_INET;
serv_addr.sin_port=htons(PORT);
inet_aton(ip, &serv_addr.sin_addr);
int IErrCount = 0;
again:
if(connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(struct sockaddr))==-1)
{
if (5 == IErrCount)
return 1;
IErrCount++;
perror("connect");
sleep(2);
goto again;
}
//if ((fp = fopen(FileName, "rb")) == NULL)
if ((fp = fopen(filepath, "rb")) == NULL)
{
perror("fopen ");
return 1;
}
recvbytes = write(sockfd, FileName, strlen(FileName));
recvbytes = read(sockfd, buf, MAXDATASIZE);
if (!memcmp(buf, "sendmsg", 7))
{
while(fgets(send_str, MAXDATASIZE, fp))
{
recvbytes = write(sockfd, send_str, strlen(send_str));
recvbytes = read(sockfd, buf, MAXDATASIZE);
if (recvbytes <= 0)
{
fclose(fp);
close(sockfd);
return 1;
}
if (memcmp(buf, "goon", 4))
{
fclose(fp);
close(sockfd);
return 1;
}
}
recvbytes = write(sockfd, "end", 3);
}
else
{
fclose(fp);
close(sockfd);
return 1;
}
memset(buf, 0, MAXDATASIZE);
if (read(sockfd, buf, MAXDATASIZE) <= 0)
{
close(sockfd);
return 2;
}
char *Eptr = "nginx reload error";
//printf("bf[%s]\n", buf);
int ret;
ret = strncmp(buf, Eptr, strlen(Eptr));
//printf("%d\n", ret);
if (!ret)
{
close(sockfd);
return 2;
}
close(sockfd);
return 0;
}
int mysyslog(const char * msg)
{
FILE *fp;
if ((fp = fopen("/tmp/tmp.log", "a+")) == NULL)
{
return 0;
}
fprintf(fp, "[%s]\n", msg);
fclose(fp);
return 0;
}
static void quit_handler(int signal)
{
kill(0, SIGUSR2);
syslog( LOG_NOTICE, "apuserv quit...");
// do something exit thing ,such as close socket ,close mysql,free list
// .....
//i end
exit(0);
}
static int re_conf = 0;
static void reconf_handler(int signal)
{
re_conf=1;
syslog(LOG_NOTICE,"apuserv reload configure file .");
// 请在循环体中判断，如果re_conf == 1，请再次加载配置文件。
}
static int isrunning(void)
{
int fd;
int ret;
struct flock lock;
lock.l_type = F_WRLCK;
lock.l_whence = 0;
lock.l_start = 0;
lock.l_len = 0;
const char *lckfile = "/tmp/apuserv.lock";
fd = open(lckfile,O_WRONLY|O_CREAT);
if (fd < 0) {
syslog(LOG_ERR,"can not create lock file: %s\n",lckfile);
return 1;
}
if ((ret = fcntl(fd,F_SETLK,&lock)) < 0) {
ret = fcntl(fd,F_GETLK,&lock);
if (lock.l_type != F_UNLCK) {
close(fd);
return lock.l_pid;
}
else {
fcntl(fd,F_SETLK,&lock);
}
}
return 0;
}
int MyHandleBuff(const char *buf, char *str, char *FileName, char *pth)
{
sscanf(buf, "%s %s %s", pth, FileName, str);
printf("path=%s\nfilename=%s\nip=%s\n", pth, FileName, str);
return 0;
}
int main(int argc, char **argv)
{
int sockfd,client_fd;
socklen_t sin_size;
struct sockaddr_in my_addr,remote_addr;
char buff[MAXDATASIZE];
int recvbytes;
#if 1
int pid ;
char ch ;
int ret;
int debug = 0;
signal(SIGUSR1, SIG_IGN);
signal(SIGUSR2, SIG_IGN);
signal(SIGHUP, SIG_IGN);
signal(SIGTERM, quit_handler);
syslog(LOG_NOTICE,"apuserver start....");
while ((ch = getopt(argc, argv, "dhV")) != -1) {
switch (ch) {
case 'd':
debug = 1;
break;
case 'V':
printf("Version:%s\n","1.0.0");
return 0;
case 'h':
printf(" -d use daemon mode\n");
printf(" -V show version\n");
return 0;
default:
printf(" -d use daemon mode\n");
printf(" -V show version\n");
}
}
if (debug && daemon(0,0 ) ) {
return -1;
}
if (isrunning()) {
fprintf(stderr, "apuserv is already running\n");
syslog(LOG_INFO,"apuserv is already running\n");
exit(0);
}
while (1) {
pid = fork();
if (pid < 0)
return -1;
if (pid == 0)
break;
while ((ret = waitpid(pid, NULL, 0)) != pid) {
syslog(LOG_NOTICE, "waitpid want %d, but got %d", pid, ret);
if (ret < 0)
syslog(LOG_NOTICE, "waitpid errno:%d", errno);
}
kill(0, SIGUSR2);
sleep(1);
syslog(LOG_NOTICE,"restart apuserver");
}
signal(SIGHUP, reconf_handler);
signal(SIGPIPE, SIG_IGN);
signal(SIGUSR1,SIG_IGN);
signal(SIGUSR2, SIG_DFL);
signal(SIGTERM, SIG_DFL);
#endif
if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)
{
perror("socket");
exit(1);
}
bzero(&my_addr,sizeof(struct sockaddr_in));
my_addr.sin_family=AF_INET;
my_addr.sin_port=htons(SERVPORT);
my_addr.sin_addr.s_addr = htonl(INADDR_ANY);
if(bind(sockfd,(struct sockaddr *)&my_addr,sizeof(struct sockaddr))==-1)
{
perror("bind");
exit(1);
}
if(listen(sockfd,BACKLOG)==-1)
{
perror("listen");
exit(1);
}
int nret;
while(1)
{
sin_size = sizeof(struct sockaddr_in);
if((client_fd = accept(sockfd, (struct sockaddr *)&remote_addr, &sin_size))==-1)
{
perror("falied accept");
continue;
}
memset(buff, 0, MAXDATASIZE);
recvbytes = read(client_fd, buff, MAXDATASIZE);
char str[16] = {0};
char FileName[128] = {0};
char path[128] = {0};
MyHandleBuff(buff, str, FileName, path);
if (recvbytes > 0)
{
nret = SendFileToServ(path, FileName, str);
printf("nret[%d]\n", nret);
if (1 == nret)
write(client_fd, "send file error", 15);
else if(2 == nret)
write(client_fd, "reload nginx error", 18);
else
write(client_fd, "succ", 4);
}
close(client_fd);
}
}
_________________________________________________
client:
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <syslog.h>
#include <sys/time.h>
#include <string.h>
#include <fcntl.h>
#include <sys/wait.h>
#define MAXDATASIZE 1024
#define SERVPORT 20002
#define BACKLOG 10
int mysyslog(const char * msg)
{
FILE *fp;
if ((fp = fopen("/tmp/tmp.log", "a+")) == NULL)
{
return 0;
}
fprintf(fp, "[%s]\n", msg);
fclose(fp);
return 0;
}
static void quit_handler(int signal)
{
kill(0, SIGUSR2);
syslog( LOG_NOTICE, "apuserv quit...");
// do something exit thing ,such as close socket ,close mysql,free list
// .....
//i end
exit(0);
}
static int re_conf = 0;
static void reconf_handler(int signal)
{
re_conf=1;
syslog(LOG_NOTICE,"apuserv reload configure file .");
// ????·???????1nf == 1￡???′μ?????
static int isrunning(void)
{
int fd;
int ret;
struct flock lock;
lock.l_type = F_WRLCK;
lock.l_whence = 0;
lock.l_start = 0;
lock.l_len = 0;
const char *lckfile = "/tmp/dstserver.lock";
fd = open(lckfile,O_WRONLY|O_CREAT);
if (fd < 0) {
syslog(LOG_ERR,"can not create lock file: %s\n",lckfile);
return 1;
}
if ((ret = fcntl(fd,F_SETLK,&lock)) < 0) {
ret = fcntl(fd,F_GETLK,&lock);
if (lock.l_type != F_UNLCK) {
close(fd);
return lock.l_pid;
}
else {
fcntl(fd,F_SETLK,&lock);
}
}
return 0;
}
int main(int argc, char **argv)
{
int sockfd,client_fd;
socklen_t sin_size;
struct sockaddr_in my_addr,remote_addr;
char buff[MAXDATASIZE];
int recvbytes;
#if 1
int pid ;
char ch ;
int ret;
int debug = 0;
signal(SIGUSR1, SIG_IGN);
signal(SIGUSR2, SIG_IGN);
signal(SIGHUP, SIG_IGN);
signal(SIGTERM, quit_handler);
syslog(LOG_NOTICE,"dstserver start....");
while ((ch = getopt(argc, argv, "dhV")) != -1) {
switch (ch) {
case 'd':
debug = 1;
break;
case 'V':
printf("Version:%s\n","1.0.0");
return 0;
case 'h':
printf(" -d use daemon mode\n");
printf(" -V show version\n");
return 0;
default:
printf(" -d use daemon mode\n");
printf(" -V show version\n");
}
}
if (debug && daemon(0,0 ) ) {
return -1;
}
if (isrunning()) {
fprintf(stderr, "dstserver is already running\n");
syslog(LOG_INFO,"dstserver is already running\n");
exit(0);
}
while (1) {
pid = fork();
if (pid < 0)
return -1;
if (pid == 0)
break;
while ((ret = waitpid(pid, NULL, 0)) != pid) {
syslog(LOG_NOTICE, "waitpid want %d, but got %d", pid, ret);
if (ret < 0)
syslog(LOG_NOTICE, "waitpid errno:%d", errno);
}
kill(0, SIGUSR2);
sleep(1);
syslog(LOG_NOTICE,"restart apuserver");
}
signal(SIGHUP, reconf_handler);
signal(SIGPIPE, SIG_IGN);
signal(SIGUSR1,SIG_IGN);
signal(SIGUSR2, SIG_DFL);
signal(SIGTERM, SIG_DFL);
#endif
if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)
{
perror("socket");
exit(1);
}
bzero(&my_addr,sizeof(struct sockaddr_in));
my_addr.sin_family=AF_INET;
my_addr.sin_port=htons(SERVPORT);
my_addr.sin_addr.s_addr = htonl(INADDR_ANY);
if(bind(sockfd,(struct sockaddr *)&my_addr,sizeof(struct sockaddr))==-1)
{
perror("bind");
exit(1);
}
if(listen(sockfd,BACKLOG)==-1)
{
perror("listen");
exit(1);
}
char filepath[MAXDATASIZE]= {0};
FILE *fp;
while(1)
{
sin_size = sizeof(struct sockaddr_in);
if((client_fd = accept(sockfd, (struct sockaddr *)&remote_addr, &sin_size))==-1)
{
perror("falied accept");
continue;
}
memset(buff, 0, MAXDATASIZE);
recvbytes = read(client_fd, buff, MAXDATASIZE);
sprintf(filepath, "/etc/nginx/url_rule/%s", buff);
if ((fp = fopen(filepath, "wb")) == NULL)
{
perror("fopen");
close(client_fd);
continue;
}
write(client_fd, "sendmsg", 7);
while(read(client_fd, buff, MAXDATASIZE))
{
if (!memcmp(buff, "end", 3))
{
fclose(fp);
break;
}
else
{
fprintf(fp, "%s", buff);
write(client_fd, "goon", 4);
}
}
//system("nginx -s reload");
char *Sptr = "nginx reload succ";
char *Eptr = "nginx reload error";
int ret;
ret = system("nginx -s reload");
printf("ret[%d]\n", ret);
if (ret != 0)
{
write(client_fd, Eptr, strlen(Eptr));
}
else
{
write(client_fd, Sptr, strlen(Sptr));
}
close(client_fd);
}
}
以前写的：内容忘记了。不是很复杂你可以自己看！
3. java socket网络编程
//==============Server.java=================//
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
public class Server {
public static void main(String[] args) throws IOException {
ServerSocket s = new ServerSocket(12345);
System.out.println("服务器就绪,请启动客户端.");
Socket so = s.accept();
byte[] buff = new byte[1024];
int read = so.getInputStream().read(buff);
String[] abc=new String(buff,0,read).split("\\D+");
int a = Integer.parseInt(abc[0]);
int b = Integer.parseInt(abc[1]);
int c = Integer.parseInt(abc[2]);
if(!cbt(a,b,c))
so.getOutputStream().write("输入的数据无法组成三角形.".getBytes());
else
so.getOutputStream().write(getArea(a,b,c).getBytes());
so.getOutputStream().flush();
so.close();
s.close();
}
private static String getArea(int a, int b, int c) {
float s = (a+b+c)/2f;
return "面积: "+Math.sqrt(s*(s-a)*(s-b)*(s-c));
}
private static boolean cbt(int a, int b, int c) {
return a>0&&b>0&&c>0&&a+b>c&&b+c>a&&a+c>b;
}
}
//=================Client.java======================//
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;
public class Client {
public static void main(String[] args) throws UnknownHostException, IOException {
System.out.println("输入三角形的三边并用逗号隔开,如: (3,4,5) ");
byte[] buff=new byte[64];
int r = System.in.read(buff);
String ipaddr = "localhost";//根据情况改变,在本机调试就不改了
Socket so = new Socket(ipaddr,12345);
so.getOutputStream().write(new String(buff,0,r).getBytes());
r = so.getInputStream().read(buff);
so.close();
String rs = new String(buff,0,r);
System.out.println(rs);
}
}
//先启动Server,再启动Client
4. Python中两种网络编程方式：Socket和HTTP协议
本文深入探讨了Python中的网络编程，主要分为两种方式：Socket编程与基于HTTP协议的网络编程。以下为详细解析：
1. Socket编程介绍：Socket是实现网络通信的基本组件，Python提供socket模块简化了Socket编程。以下是一个简单的Socket服务器与客户端实例：
运行示例代码，即可搭建基本的Socket服务器，实现客户端与服务器间的数据传输。
2. HTTP协议实践：HTTP是一种用于传输超媒体文档的应用层协议。Python中常用的库是requests，以下为HTTP GET请求示例：
通过requests.get()函数发送HTTP GET请求，获取响应的状态码与内容。
3. Socket网络通信应用：Socket编程适用于构建各种网络应用，如即时通讯、文件传输等。以下为简单Socket聊天程序示例：
运行代码实现基于Socket的聊天程序，客户端与服务器间能互发消息。
4. HTTP协议网络通信：HTTP协议在Web开发和API交互中广泛使用。requests库提供HTTP请求与响应处理功能，以下为HTTP POST请求示例：
使用requests发送HTTP POST请求，并获取服务器响应。
5. Socket多线程网络通信：实际应用中，处理多客户端连接请求时，多线程能提高并发处理能力。Python的threading模块实现多线程网络通信，以下为示例：
通过创建新线程处理每个客户端连接，实现多客户端请求的并发处理。
6. HTTP多线程网络通信：基于HTTP协议的多线程网络通信也常见于Web应用中，以下为示例：
使用多线程处理HTTP连接请求，提高服务器并发处理能力。
总结，Python提供丰富的网络编程工具，如socket与requests库。Socket编程适用于定制化通信需求，HTTP协议则方便Web应用与API交互。通过本文学习，了解如何在不同场景下运用Python网络编程技术，助力项目开发。
5. socket接口网络编程
面向无连接的端对端通信
//#include <winsock2.h>
//#pragma comment(lib,"WS2_32.lib")
WSADATA wsd;
SOCKET s;
char buf[1024];
if(WSAStartup(MAKEWORD(2,2),&wsd)!=0)
{
return -1;//失败
}
s=socket(AF_INET,SOCK_DGRAM,0);
if(s==INVALID_SOCKET)
{
WSACleanup();
return -1;//创建套接字失败
}
SOCKADDR_IN servAddr;
servAddr.sin_family=AF_INET;
servAddr.sin_addr.s_addr=inet_addr(%%1);
servAddr.sin_port=htons(INADDR_ANY);
if(bind(s,(SOCKADDR*)&servAddr,sizeof(SOCKADDR_IN))==SOCKET_ERROR)
{
closesocket(s);
WSACleanup();
return -1;//绑定套接字失败
}
int nServAddrlen=sizeof(servAddr);
ZeroMemory(buf,sizeof(buf));
if(recvfrom(s,buf,size(buf),0,(SOCKADDR*)&servAddr,nServAddrlen)==SOCKET_ERROR)
{
closesocket(s);
WSACleanup();
return -1;//接收数据失败
}
CString %%2(buf);
ZeroMemory(buf,sizeof(buf));
strcpy(buf,%%3);
SOCKADDR_IN clientAddr;
clientAddr.sin_family=AF_INET;
clientAddr.sin_addr.s_addr=inet_addr(%%4);
clientAddr.sin_port=htons((short)%%5);
int nClientlen=size(clientAddr);
if(sendto(s,buf,sizeof(buf),0,(SOCKADDR*)&clientAddr,nClientlen)==SOCKET_ERROR)
{
closesocket(s);
WSACleanup();
return -1;//向服务器发送数据失败
}
closesocket(s);
WSACleanup();
6. linux下socket 网络编程(客户端向服务器端发送文件) 求源代码 大哥大姐帮帮忙 ,。。谢谢
源代码奉上，流程图。。。这个太简单了，你自己看看。。。。。。。
//TCP
//服务器端程序
#include< stdio.h >
#include< stdlib.h >
#include< windows.h >
#include< winsock.h >
#include< string.h >
#pragma comment( lib, "ws2_32.lib" )
#define PORT 2046
#define BACKLOG 10
#define TRUE 1
void main( void )
{
int iServerSock;
int iClientSock;
char *buf = "hello, world!\n";
struct sockaddr_in ServerAddr;
struct sockaddr_in ClientAddr;
int sin_size;
WSADATA WSAData;
if( WSAStartup( MAKEWORD( 1, 1 ), &WSAData ) )//初始化
{
printf( "initializationing error!\n" );
WSACleanup( );
exit( 0 );
}
if( ( iServerSock = socket( AF_INET, SOCK_STREAM, 0 ) ) == INVALID_SOCKET )
{
printf( "创建套接字失败!\n" );
WSACleanup( );
exit( 0 );
}
ServerAddr.sin_family = AF_INET;
ServerAddr.sin_port = htons( PORT );//监视的端口号
ServerAddr.sin_addr.s_addr = INADDR_ANY;//本地IP
memset( & ( ServerAddr.sin_zero ), 0, sizeof( ServerAddr.sin_zero ) );
if( bind( iServerSock, ( struct sockaddr * )&ServerAddr, sizeof( struct sockaddr ) ) == -1 )
{
printf( "bind调用失败!\n" );
WSACleanup( );
exit( 0 );
}
if( listen( iServerSock, BACKLOG ) == -1 )
{
printf( "listen调用失败!\n" );
WSACleanup( );
exit( 0 );
}
while( TRUE )
{
sin_size = sizeof( struct sockaddr_in );
iClientSock = accept( iServerSock, ( struct sockaddr * )&ClientAddr, &sin_size );
if( iClientSock == -1 )
{
printf( "accept调用失败!\n" );
WSACleanup( );
exit( 0 );
}
printf( "服务器连接到%s\n", inet_ntoa( ClientAddr.sin_addr ) );
if( send( iClientSock, buf, strlen( buf ), 0 ) == -1 )
{
printf( "send调用失败!" );
closesocket( iClientSock );
WSACleanup( );
exit( 0 );
}
}
}
/////客户端程序
#include< stdio.h >
#include< stdlib.h >
#include< windows.h >
#include< winsock.h >
#include< string.h >
#pragma comment( lib, "ws2_32.lib" )
#define PORT 2046
#define BACKLOG 10
#define TRUE 1
#define MAXDATASIZE 100
void main( void )
{
int iClientSock;
char buf[ MAXDATASIZE ];
struct sockaddr_in ServerAddr;
int numbytes;
// struct hostent *he;
WSADATA WSAData;
// int sin_size;
/* if( ( he = gethostbyname( "liuys" ) ) == NULL )
{
printf( "gethostbyname调用失败!" );
WSACleanup( );
exit( 0 );
}
*/
if( WSAStartup( MAKEWORD( 1, 1 ), &WSAData ) )//初始化
{
printf( "initializationing error!\n" );
WSACleanup( );
exit( 0 );
}
if( ( iClientSock = socket( AF_INET, SOCK_STREAM, 0 ) ) == INVALID_SOCKET )
{
printf( "创建套接字失败!\n" );
WSACleanup( );
exit( 0 );
}
ServerAddr.sin_family = AF_INET;
ServerAddr.sin_port = htons( PORT );
// ServerAddr.sin_addr = *( ( struct in_addr * )he->h_addr );
ServerAddr.sin_addr.s_addr = inet_addr( "192.168.2.194" );//记得换IP
memset( &( ServerAddr.sin_zero ), 0, sizeof( ServerAddr.sin_zero ) );
if( connect( iClientSock, ( struct sockaddr * ) & ServerAddr, sizeof( struct sockaddr ) ) == -1 )
{
printf( "connect失败!" );
WSACleanup( );
exit( 0 );
}
numbytes = recv( iClientSock, buf, MAXDATASIZE, 0 );
if( numbytes == -1 )
{
printf( "recv失败!" );
WSACleanup( );
exit( 0 );
}
buf[ numbytes ] = '\0';
printf( "Received: %s", buf );
closesocket( iClientSock );
WSACleanup( );
}
/////UDP
//服务器
#include< stdio.h >
#include< string.h >
#include< winsock.h >
#include< windows.h >
#pragma comment( lib, "ws2_32.lib" )
#define PORT 2046
#define BACKLOG 10
#define TRUE 1
#define MAXDATASIZE 1000
void main( void )
{
int iServerSock;
// int iClientSock;
int addr_len;
int numbytes;
char buf[ MAXDATASIZE ];
struct sockaddr_in ServerAddr;
struct sockaddr_in ClientAddr;
WSADATA WSAData;
if( WSAStartup( MAKEWORD( 1, 1 ), &WSAData ) )
{
printf( "initializationing error!\n" );
WSACleanup( );
exit( 0 );
}
iServerSock = socket( AF_INET, SOCK_DGRAM, 0 );
if( iServerSock == INVALID_SOCKET )
{
printf( "创建套接字失败!\n" );
WSACleanup( );
exit( 0 );
}
ServerAddr.sin_family = AF_INET;
ServerAddr.sin_port = htons( PORT );//监视的端口号
ServerAddr.sin_addr.s_addr = INADDR_ANY;//本地IP
memset( & ( ServerAddr.sin_zero ), 0, sizeof( ServerAddr.sin_zero ) );
if( bind( iServerSock, ( struct sockaddr * )&ServerAddr, sizeof( struct sockaddr ) ) == -1 )
{
printf( "bind调用失败!\n" );
WSACleanup( );
exit( 0 );
}
addr_len = sizeof( struct sockaddr );
numbytes = recvfrom( iServerSock, buf, MAXDATASIZE, 0, ( struct sockaddr * ) & ClientAddr, &addr_len );
if( numbytes == -1 )
{
printf( "recvfrom调用失败!\n" );
WSACleanup( );
exit( 0 );
}
printf( "got packet from %s\n", inet_ntoa( ClientAddr.sin_addr ) );
printf( "packet is %d bytes long\n", numbytes );
buf[ numbytes ] = '\0';
printf( "packet contains \"%s\"\n", buf );
closesocket( iServerSock );
WSACleanup( );
}
//客户端
#include< stdio.h >
#include< stdlib.h >
#include< windows.h >
#include< winsock.h >
#include< string.h >
#pragma comment( lib, "ws2_32.lib" )
#define PORT 2046
#define MAXDATASIZE 100
void main( void )
{
int iClientSock;
struct sockaddr_in ServerAddr;
int numbytes;
char buf[ MAXDATASIZE ] = { 0 };
WSADATA WSAData;
if( WSAStartup( MAKEWORD( 1, 1 ), &WSAData ) )
{
printf( "initializationing error!\n" );
WSACleanup( );
exit( 0 );
}
if( ( iClientSock = socket( AF_INET, SOCK_DGRAM, 0 ) ) == -1 )
{
printf( "创建套接字失败!\n" );
WSACleanup( );
exit( 0 );
}
ServerAddr.sin_family = AF_INET;
ServerAddr.sin_port = htons( PORT );
ServerAddr.sin_addr.s_addr = inet_addr( "192.168.2.194" );//记得换IP
memset( &( ServerAddr.sin_zero ), 0, sizeof( ServerAddr.sin_zero ) );
numbytes = sendto( iClientSock, buf, strlen( buf ), 0, ( struct sockaddr * ) & ServerAddr, sizeof( struct sockaddr ) );
if( numbytes == -1 )
{
printf( "sendto调用失败!\n" );
WSACleanup( );
exit( 0 );
}
printf( "sent %d bytes to %s\n", numbytes, inet_ntoa( ServerAddr.sin_addr ) );
closesocket( iClientSock );
WSACleanup( );
}
7. 网络fd是什么意思
网络fd是网络编程中常见的术语，是指一个socket文件描述符，在程序中用于进行网络通信的端口。通俗地说，fd就是网络通信的句柄，我们可以通过fd来进行socket的IO操作。在Linux系统中，每个进程都有对应的文件描述符表，来记录当前进程打开的文件或者socket等资源的文件描述符。
在进行网络编程时，我们通常会使用C语言中的socket函数来创建socket并建立连接，这时会得到一个返回类型为int的文件描述符fd。我们可以使用fd来进行recv、send等函数的调用，实现网络数据的收发。在使用完fd后，我们还需要通过调用close函数来释放fd，防止内存泄漏。
网络fd是网络编程中非常重要的概念，它可以被用于多种网络协议的实现，如TCP、UDP、HTTP等。正确地使用fd，不仅可以提升网络编程的效率，也能够保证程序的稳定性。因此，在进行网络编程时，我们需要注意fd的使用，尽量避免出现fd泄漏、fd未释放等问题，以确保程序的安全和稳定性。