如何用C语言编写一个简单的聊天室程序

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

#include<errno.h>

#include<sys/socket.h>

#include<arpa/inet.h>

#include<netinet/in.h>

#include<sys/types.h>

#include<unistd.h>

#include<sys/time.h>

#defineBUFLEN1024

#definePORT6666

#defineLISTNUM20

intmain()

{

intsockfd,newfd

structsockaddr_ins_addr,c_addr

charbuf[BUFLEN]

socklen_tlen

unsignedintport,listnum

fd_setrfds

structtimevaltv

intretval,maxfd

/*建立socket*/

if((sockfd=socket(PF_INET,SOCK_STREAM,0))==-1){

perror("socket")

exit(errno)

}else

printf("socketcreatesuccess!\n")

memset(&s_addr,0,sizeof(s_addr))

s_addr.sin_family=AF_INET

s_addr.sin_port=htons(PORT)

s_addr.sin_addr.s_addr=htons(INADDR_ANY)

/*把地址和端口帮定到套接字上*/

if((bind(sockfd,(structsockaddr*)&s_addr,sizeof(structsockaddr)))==-1){

perror("bind")

exit(errno)

}else

printf("bindsuccess!\n")

/*侦听本地端口*/

if(listen(sockfd,listnum)==-1){

perror("listen")

exit(errno)

}else

printf("theserverislistening!\n")

while(1){

printf("*****************聊天开始***************\n")

len=sizeof(structsockaddr)

if((newfd=accept(sockfd,(structsockaddr*)&c_addr,&len))==-1){

perror("accept")

exit(errno)

}else

printf("正在与您聊天的客户端是：%s:%d\n",inet_ntoa(c_addr.sin_addr),ntohs(c_addr.sin_port))

while(1){

FD_ZERO(&rfds)

FD_SET(0,&rfds)

maxfd=0

FD_SET(newfd,&rfds)

/*找出文件描述符集合中最大的文件描述符*/

if(maxfd<newfd)

maxfd=newfd

/*设置超时时间*/

tv.tv_sec=6

tv.tv_usec=0

/*等待聊天*/

retval=select(maxfd+1,&rfds,NULL,NULL,&tv)

if(retval==-1){

printf("select出错，与该客户端连接的程序将退出\n")

break

}elseif(retval==0){

printf("waiting...\n")

continue

}else{

/*用户输入信息了*/

if(FD_ISSET(0,&rfds)){

/******发送消息*******/

memset(buf,0,sizeof(buf))

/*fgets函数：从流中读取BUFLEN-1个字符*/

fgets(buf,BUFLEN,stdin)

/*打印发送的消息*/

//fputs(buf,stdout)

if(!strncasecmp(buf,"quit",4)){

printf("server请求终止聊天!\n")

break

}

len=send(newfd,buf,strlen(buf),0)

if(len>0)

printf("\t消息发送成功：%s\n",buf)

else{

printf("消息发送失败!\n")

break

}

}

/*客户端发来了消息*/

if(FD_ISSET(newfd,&rfds)){

/******接收消息*******/

memset(buf,0,sizeof(buf))

/*fgets函数：从流中读取BUFLEN-1个字符*/

len=recv(newfd,buf,BUFLEN,0)

if(len>0)

printf("客户端发来的信息是：%s\n",buf)

else{

if(len<0)

printf("接受消息失败！\n")

else

printf("客户端退出了，聊天终止！\n")

break

}

}

}

}

/*关闭聊天的套接字*/

close(newfd)

/*是否退出服务器*/

printf("服务器是否退出程序：y->是；n->否?")

bzero(buf,BUFLEN)

fgets(buf,BUFLEN,stdin)

if(!strncasecmp(buf,"y",1)){

printf("server退出!\n")

break

}

}

/*关闭服务器的套接字*/

close(sockfd)

return0

}

扩展资料

C语言编写一个简单的ATM系统

#include<stdio.h>

intchoice

intshow_menu()

doubleget_money()

voiddeposit(double)

voidwithdraw(double)

doubleaccount=0.0

intmain(intargc,constchar*argv[])

{

system("COLOR5f")

show_menu()

doubletemp

while(choice!=0)

{

system("cls")

switch(choice)

{

case1:

printf("您的当前余额为:%.2f\n",get_money())

break

case2:

printf("请输入您的存款金额:\n")

scanf("%lf",&temp)

deposit(temp)

printf("您的当前余额为:%.2f\n",get_money())

break

case3:

printf("您的当前余额为:%.2f\n",get_money())

printf("请输入您的取款金额:\n")

scanf("%lf",&temp)

withdraw(temp)

printf("您的当前余额为:%.2f\n",get_money())

break

default:

break

}

getchar()

choice=show_menu()

}

printf("欢迎您下次再来中国银行为您提供的服务，再见！\n")

return0

}

intshow_menu()

{

printf("*****欢迎使用中国银行行为为您提供的服务******\n")

printf("\n1.查询账户余额2.存款3.取款0.退出\n")

printf("\n请选择服务种类：")

scanf("%d",&choice)

returnchoice

}

doubleget_money()

{

returnaccount

}

voiddeposit(doublemoney)

{

account=account+money

}

voidwithdraw(doublemoney)

{

if(account<money)

printf("抱歉，余额不足，不能取%.2f这么多钱!\n",money)

else

account=account-money

}

#include <stdio.h>#include <stdlib.h>#include <string.h>#define szSTR 64 #define fileDB "c:\\contact.txt" struct CONTACT { char name[szSTR]/*姓名*/ char unit[szSTR]/*工作单位*/ char tele[szSTR]/*电话*/ char mail[szSTR]/*mail*/ }typedef struct CONTACT CON#define BNAME 1 #define BUNIT 2 #define BTELE 4 #define BMAIL 8 #define BFULL 0xFF int OPER[5] = void input(CON * s, int mask) { if(mask &BNAME) if(mask &BUNIT) if(mask &BTELE) if(mask &BMAIL) }/*end input*/ void show (int id, CON * s) { if(!s) return if(id) printf("%d\t%s\t%s\t%s\t%s\n", id, s->name , s->unit , s->tele , s->mail )else printf("%s%s%s%s\n", s->name , s->unit , s->tele , s->mail )/*end if*/ }/*end show*/ void regist(void) { CON sFILE * f = 0input(&s, BFULL)f = fopen(fileDB, "ab")fwrite(&s,sizeof(s),1,f)fclose(f)printf("资料已保存!\n")}/*end regist*/ int browse(char * key, fpos_t * p, CON * s) { FILE * f =0int i = 0, r = 0CON tchar * a = 0, * b = 0fpos_t q if(!s) return 0f = fopen(fileDB, "rb")if(!f) { printf("数据库暂无记录\n")return 0}/*end if*/ printf("编号\t姓名\t单位\t电话\t电邮\n")printf("------------------------------------------------\n")while(!feof(f)) { fgetpos(f, &q)r = fread(&t, sizeof(t), 1, f)if(r<1)breakif(t.name[0]==0) continueif(key) { a = strstr(t.name , key)b = strstr(t.tele , key)if(a == 0 &&b == 0) continue}/*end if*/ if(p) *p = qif(s) memcpy(s, &t, sizeof(t))i++show(i, &t)}/*end while*/ fclose(f)printf("------------------------------------------------\n")return i}/*end browse*/ fpos_t query(CON * s) { char key[szSTR]=""fpos_t p = 0int r = 0printf("请输入姓名或者电话号码:")scanf("%s", key)r = browse(key, &p, s)return r?p:-1}/*end query*/ void clear(void) { FILE * f = 0CON sfpos_t p = query(&s)if(p<0) returnf = fopen(fileDB, "rb+")fsetpos(f, &p)memset(&s, 0, sizeof(s))fwrite(&s, sizeof(s),1, f)fclose(f)printf("记录已删除!\n")}/*end clear*/ void modify(void) { FILE * f = 0CON sint cmd = 0fpos_t p = query(&s)if(p<0) returnf = fopen(fileDB, "rb+")fsetpos(f, &p)for() { show(0, &s)printf("请选择:1-姓名2-工作单位3-电话4-电邮5-保存并退出6-放弃修改并退出\n")scanf("%d", &cmd)switch(cmd) { case 1: case 2: case 3: case 4: input(&s, OPER[cmd])breakcase 5: fsetpos(f, &p)fwrite(&s, sizeof(s), 1, f)case 6: fclose(f)returndefault: printf("错误的 *** 作,请重新输入。\n")}/*end case*/ }/*mext*/ }/*end clear*/ int main(void) { int cmd = 0CON sfor() { printf("欢迎使用通信簿!请选择:1-添加2-查询3-删除4-修改5-全部输出0-退出\n")scanf("%d", &cmd)switch(cmd) { case 0: return 0case 1: regist()breakcase 2: query(&s)breakcase 3: clear()breakcase 4: modify()breakcase 5: browse(0, 0, &s)break}//end case } return 0}

记得采纳啊

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