并发服务器 典型模型

#include "header.h"#define MAXBUF 1024typedef struct sockaddr SA;void child_function(int connect_fd);void child_function(int connect_fd){char buffer[MAXBUF];memset(buffer,'\0',sizeof(buffer));if(read(connect_fd,buffer,sizeof(buffer)) < 0){perror("read error");exit(-1);}printf("the client message :%s\n",buffer);int i;for(i = 0; i < strlen(buffer); i++){buffer[i] = toupper(buffer[i]);}if(write(connect_fd,buffer,strlen(buffer)) < 0){perror("write error");exit(-1);}close(connect_fd);}int main(void){int listen_fd,connect_fd;struct sockaddr_in serveraddr,clientaddr;socklen_t addrlen;pid_t pid;if((listen_fd=socket(AF_INET,SOCK_STREAM,0)) == -1){perror("socket fail");exit(-1);}  memset(&serveraddr,0,sizeof(serveraddr));serveraddr.sin_family=AF_INET;serveraddr.sin_port=htons(8000);serveraddr.sin_addr.s_addr=inet_addr("127.0.0.1");if(bind(listen_fd,(SA *)&serveraddr,sizeof(serveraddr)) == -1){perror("bind fail");exit(-1);}if(listen(listen_fd,10) == -1){perror("listen fail");exit(-1);}while(1){addrlen = sizeof(clientaddr);if((connect_fd=accept(listen_fd,(SA *)&clientaddr,&addrlen)) == -1){perror("accept fail");exit(-1);}printf("a new connection :%d\n",connect_fd);if((pid = fork()) == 0){close(listen_fd);child_function(connect_fd);exit(0);}else if(pid < 0){perror("fork");break;}else{close(connect_fd);}}close(listen_fd);}