linux网络编程send

❶ linux阒诲炰笌闱为樆濉濒inux阒诲为潪阒诲

鍦ㄩ潪阒诲炴ā寮忎笂镐庝箞鐭ラ亾recv鎺ユ敹鏁版嵁瀹屾垚锛

浠linux涓媡cpsocket缂栫▼涓轰緥锛氶樆濉炲氨鏄痳ecv/read镄勬椂鍊檚ocket鎺ユ敹缂揿啿鍖鸿佹槸链夋暟鎹灏辫伙纴娌℃暟鎹鎴戝氨涓鐩寸浔瑙夎禆镌涓嶈蛋锛岀洿鍒版湁鏁版嵁𨱒ヤ简璇诲畬鎴戞墠璧般

send/write镄勬椂鍊欙纴瑕佹槸鍙戦佺紦鍐插尯婊′简锛屾病链夌┖闂寸户缁鍙戦佷简鎴戜篃涓鐩寸浔瑙夎禆镌涓嶈蛋锛岀洿鍒板彂阃佺紦鍐插尯鑵惧嚭瓒冲熺殑绌洪棿璁╂垜鎶婃暟鎹鍏ㄩ儴濉炲埌鍙戦佺紦鍐插尯閲屾垜镓嶈蛋銆

锛埚綋铹跺傛灉浣犻氲繃setsockopt璁剧疆浜呜诲啓瓒呮椂锛岃秴镞舵椂闂村埌浜呜缮鏄浼氲繑锲-1鍜孍AGAIN锛屼笉鍐岖浔瑙夌瓑寰咃级

闱为樆濉炲氨鏄痳ecv/read镄勬椂鍊欙纴瑕佹槸鎺ユ敹缂揿啿鍖烘湁鏁版嵁鎴戝氨璇诲畬锛屾病链夋暟鎹鎴戠洿鎺ュ甫镌杩斿洖镄-1鍜孍GAIN璧颁汉锛岀粷涓岖浔瑙夌瓑寰呰借镞堕棿銆

write/send镄勬椂鍊欙纴瑕佹槸鍙戦佺紦鍐插尯链夎冻澶熺殑绌洪棿锛屽氨绔嫔埢鎶婃暟鎹濉炲埌鍙戦佺紦鍐插尯铡伙纴铹跺悗璧颁汉锛屽傛灉鍙戦佺紦瀛桦尯婊′简锛岀┖闂翠笉瓒筹纴闾ｇ洿鎺ュ甫镌杩斿洖镄-1鍜孍AGAIN璧颁汉銆傝呖浜嶪O澶氲矾澶岖敤锛岄栧厛瑕佺悊瑙ｇ殑鏄锛屾搷浣灭郴缁熶负浣犳彁渚涗简涓涓锷熻兘锛屽綋浣犵殑镆愪釜socket鎺ユ敹缂揿瓨鍖烘湁鏁版嵁鍙璇伙纴鎴栬呭彂阃佺紦鍐插尯链夌┖闂村彲鍐欑殑镞跺欙纴瀹冨彲浠ョ粰浣犱竴涓阃氱煡銆

杩欐牱褰挞厤钖堥潪阒诲炵殑socket浣跨敤镞讹纴鍙链夊綋绯荤粺阃氱煡鎴戝摢涓鎻忚堪绗﹀彲璇讳简锛屾垜镓嶅幓镓ц宺ead镎崭綔锛屽彲浠ヤ缭璇佹疮娆read閮借兘璇诲埌链夋晥鏁版嵁钥屼笉锅氱函杩斿洖-1鍜孍AGAIN镄勬棤鐢ㄥ姛銆

鍐欐搷浣灭被浼笺

镎崭綔绯荤粺镄勮繖涓锷熻兘阃氲繃select/poll/epoll涔嬬被镄勭郴缁熻皟鐢ㄥ嚱鏁版潵浣跨敤锛岃繖浜涘嚱鏁伴兘鍙浠ュ悓镞剁洃瑙嗗氢釜鎻忚堪绗︾殑璇诲啓灏辩华鐘跺喌锛岃繖镙凤纴澶氢釜鎻忚堪绗︾殑I/O镎崭綔閮借兘鍦ㄤ竴涓绾跨▼鍐呭畬鎴愶纴杩椤氨鍙献/O澶氲矾澶岖敤锛岃繖閲岀殑钬滃岖敤钬濇寚镄勬槸澶岖敤钖屼竴涓绾跨▼銆傝呖浜庝簨浠堕┍锷锛屽叾瀹炴槸I/O澶氲矾澶岖敤镄勪竴涓鍙﹀栫殑绉板懠銆傝呖浜庡纾姝ュ悓姝ワ纴鎴戜滑甯歌佺殑linux涓嬬殑缃戠粶缂栫▼妯″瀷澶ч儴鍒嗛兘鏄钖屾io锛屼互璇绘搷浣滀负渚嬶纴链璐ㄤ笂閮芥槸闇瑕佺敤鎴疯皟鐢╮ead/recv铡讳粠鍐呮牳缂揿啿鍖烘妸鏁版嵁璇诲畬鍐嶅勭悊涓氩姟阃昏緫銆

寮傛io鍒欐槸鍐呮牳宸茬粡鎶婃暟鎹璇诲ソ浜嗭纴鐢ㄦ埛鐩存帴澶勭悊阃昏緫銆

寮傛IO鍦╨inux涓嬩竴鑸鏄鐢╝io搴撱

linuxaccept()鍑芥暟涓鐩村勪簬阒诲炵姸镐,浠涔埚师锲狅纻

accept锛堬级鍑芥暟灏辨槸阒诲炵殑鍟婏纴瑕佺瓑寰呮帴鏀跺埌链夊㈡埛绔璇锋眰镓嶅彲浠ヨ繘琛屽悗缁镄勬搷浣滐纴浣犳墍璋撶殑涓嶅彲浠ユ槸鎸囦粈涔堬纻

open绯荤粺浣跨敤鎶宸э纻

open绯荤粺鏄澶氱嶈瑷銆佺幆澧幂殑涓绉嶅嚱鏁般

LINUX涓璷pen鍑芥暟浣灭敤锛氭墦寮鍜屽垱寤烘枃浠躲侾B绋嫔簭璇瑷涓璷pen锷熻兘锛氭墦寮绐楀彛銆

瀵逛簬open绯荤粺𨱒ヨ达纴绗涓変釜鍙傛暟浠呭綋鍒涘缓鏂版枃浠舵椂锛埚嵆浣跨敤浜哋_CREAT镞讹级镓崭娇鐢锛岀敤浜庢寚瀹氭枃浠剁殑璁块梾𨱒冮檺浣嶃

pathname鏄寰呮墦寮/鍒涘缓鏂囦欢镄凯OSIX璺寰勫悕锛沠lags鐢ㄤ簬鎸囧畾鏂囦欢镄勬墦寮/鍒涘缓妯″纺锛岃繖涓鍙傛暟鍙鐢变互涓嫔父閲忛氲繃阃昏緫浣嶆垨阃昏緫鏋勬垚銆

镓揿紑/鍒涘缓鏂囦欢镞讹纴镊冲皯寰椾娇鐢ㄤ笂杩颁笁涓甯搁噺涓镄勪竴涓銆

浠ヤ笅甯搁噺鏄阃夌敤镄勶细

1.璁剧疆涓洪潪阒诲炴ā寮

2.浠ヤ笅涓変釜甯搁噺钖屾牱鏄阃夌敤镄勶纴瀹冧滑鐢ㄤ簬钖屾ヨ緭鍏ヨ緭鍑

3.open杩斿洖镄勬枃浠舵弿杩扮︿竴瀹氭槸链灏忕殑链琚浣跨敤镄勬弿杩扮︺

❷ 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！

❸ linux 网络编程 send 做了什么操作

send解析
sockfd：指定发送端套接字描述符。
buff： 存放要发送数据的缓冲区
nbytes: 实际要改善的数据的字节数
flags： 一般设置为0
1) send先比较发送数据的长度nbytes和套接字sockfd的发送缓冲区的长度，如果nbytes > 套接字sockfd的发送缓冲区的长度, 该函数返回SOCKET_ERROR;
2) 如果nbtyes <= 套接字sockfd的发送缓冲区的长度，那么send先检查协议是否正在发送sockfd的发送缓冲区中的数据，如果是就等待协议把数据发送完，如果协议还没有开始发送sockfd的发送缓冲区中的数据或者sockfd的发送缓冲区中没有数据，那么send就比较sockfd的发送缓冲区的剩余空间和nbytes
3) 如果 nbytes > 套接字sockfd的发送缓冲区剩余空间的长度，send就一起等待协议把套接字sockfd的发送缓冲区中的数据发送完
4) 如果 nbytes < 套接字sockfd的发送缓冲区剩余空间大小，send就仅仅把buf中的数据到剩余空间里(注意并不是send把套接字sockfd的发送缓冲区中的数据传到连接的另一端的，而是协议传送的，send仅仅是把buf中的数据到套接字sockfd的发送缓冲区的剩余空间里)。
5) 如果send函数成功，就返回实际的字节数，如果send在数据时出现错误，那么send就返回SOCKET_ERROR; 如果在等待协议传送数据时网络断开，send函数也返回SOCKET_ERROR。
6) send函数把buff中的数据成功到sockfd的改善缓冲区的剩余空间后它就返回了，但是此时这些数据并不一定马上被传到连接的另一端。如果协议在后续的传送过程中出现网络错误的话，那么下一个socket函数就会返回SOCKET_ERROR。（每一个除send的socket函数在执行的最开始总要先等待套接字的发送缓冲区中的数据被协议传递完毕才能继续，如果在等待时出现网络错误那么该socket函数就返回SOCKET_ERROR）
7) 在unix系统下，如果send在等待协议传送数据时网络断开，调用send的进程会接收到一个SIGPIPE信号，进程对该信号的处理是进程终止。

❹ 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( );
}