网络socket套接字编程服务器客户端程序

#include "commhead.h" struct userinfo{ char userName[32]; char passWord[32]; }; struct userinfo users[]={ {"linux","linux"}, {"admin","admin"}, {" "," "} }; /* *find user in user table ,return -1,on error,return user on success *其实我们有更好的处理用户信息的方法！在这里我们暂时还是这样使用！ * */ int findName(const char *userName) { int i; if(NULL == userName){ printf("The name is empty!\n"); return -1; } /* *Loop in user table to find the user! * */ for(i = 0; users[i].userName[0] != ' ';i++){ if(!strcmp(userName,users[i].userName)){ return i; } } printf("The user is invalid!\n"); return -1; } void sendData(int conn_fd,const char *string) { ssize_t nleft; ssize_t nwrite; /*if(send(conn_fd,string,sizeof(string),0) < 0){ perror("send"); exit(-1); } */ nleft = strlen(string); printf("send data %s with length %d\n",string,nleft); while(nleft > 0){ if((nwrite = send(conn_fd,string,nleft,0)) < 0){ perror("send"); exit(-1); } nleft -= nwrite; } } int main(int argc,char **argv) { int serverFd,connectFd; int optionValue; int flagRecv = USER_NAME; int ret; int nameNum;//the number in user table pid_t pid; socklen_t addrLen; struct sockaddr_in clientAddr,serverAddr; char recvBuf[128]; static char ipBuf[33]; addrLen = sizeof(struct sockaddr_in); if((serverFd = socket(AF_INET,SOCK_STREAM,0)) < 0){ perror("socket"); exit(EXIT_FAILURE); } memset(&serverAddr,0,sizeof(struct sockaddr_in)); serverAddr.sin_family = AF_INET; serverAddr.sin_port = htons(SERVER_PORT); serverAddr.sin_addr.s_addr = htonl(INADDR_ANY); optionValue = 1; if(setsockopt(serverFd,SOL_SOCKET,SO_REUSEADDR,&optionValue,sizeof(optionValue)) < 0){ perror("setsockopt"); exit(EXIT_FAILURE); } if(bind(serverFd,(struct sockaddr *)&serverAddr,addrLen) < 0){ perror("bind"); exit(EXIT_FAILURE); } if(listen(serverFd,LISTEN_NUM) < 0){ perror("listen"); exit(EXIT_FAILURE); } //printf("The server is running...,we are listening...\n"); while(1){ printf("The server is running...,we are listening...\n"); if((connectFd = accept(serverFd,(struct sockaddr*)&clientAddr,&addrLen)) < 0){ perror("accept"); exit(EXIT_FAILURE); } if(inet_ntop(AF_INET,(char *)&clientAddr.sin_addr.s_addr,ipBuf,sizeof(ipBuf)) == NULL){ perror("inet_pton"); exit(EXIT_FAILURE); } printf("accept a new client, ip:%s\n",ipBuf); if((pid = fork()) < 0){ perror("fork"); exit(EXIT_FAILURE); } if(pid == 0){ // child process begin flagRecv = USER_NAME; while(1){ if((ret = recv(connectFd,recvBuf,sizeof(recvBuf),0)) < 0){ perror("recv"); exit(EXIT_FAILURE); } recvBuf[ret - 1] = '\0'; if(flagRecv == USER_NAME){ if((nameNum = findName(recvBuf)) < 0){ sendData(connectFd,"n\n"); printf("The user name is invalid !\n"); }else{ sendData(connectFd,"y\n"); flagRecv = PASS_WORD; printf("The user name is valid\n"); } continue; } if(flagRecv == PASS_WORD){ if(!(strcmp(users[nameNum].passWord,recvBuf))){ sendData(connectFd,"y\n"); printf("send welcome to client!\n"); sendData(connectFd,"welcome login my tcp server\n"); printf("%s login\n",users[nameNum].userName); break; // printf("This is after break!\n"); }else{ sendData(connectFd,"n\n"); printf("The pass word is error!\n"); } } }//end second while close(serverFd); close(connectFd); exit(EXIT_SUCCESS); } if( pid > 0){ close(connectFd); printf("Close socket in parent process!\n"); } }//end first while return 0;//HERE maybe never reach ,because the process will exit before; }