84 lines
2.5 KiB
C
84 lines
2.5 KiB
C
#include "common.h"
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void sigchld_handler(int sig)
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{
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while (waitpid(-1, 0, WNOHANG) > 0);
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return;
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}
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typedef void (*sighandler_t) (int sig) ;
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void Signal(int sig, sighandler_t handler){
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struct sigaction sa;
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sa.sa_handler = sigchld_handler;
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sigemptyset(&sa.sa_mask);
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sa.sa_flags = SA_RESTART; // 确保被信号中断的系统调用自动重启
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sigaction(SIGCHLD, &sa, NULL);
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}
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//工作函数
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void toggle(int conn_sock,int hit)
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{
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size_t n; int i,no=0;
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char buf[MAXLINE];
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printf("第%d个客户通信开始\n",hit);
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while((n =recv(conn_sock, buf, MAXLINE,0))> 0) {
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printf("toggle服务器收到第%d个客户第%d个消息,长度为%d字节\n", hit,++no,(int)n);
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for(i=0; i<n; i++)
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if(isupper(buf[i]))
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buf[i]=tolower(buf[i]);
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else if(islower(buf[i]))
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buf[i]=toupper(buf[i]);
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send (conn_sock, buf, n, 0);
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}
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printf("第%d个客户通信结束\n",hit);
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}
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int main(int argc, char **argv)
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{
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int listen_sock, conn_sock, port;
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struct sockaddr_in clientaddr;
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struct hostent *hp;
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char *haddrp;
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int hit;
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socklen_t clientlen=sizeof(struct sockaddr_in);
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if (argc != 2) {
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fprintf(stderr, "usage: %s <port>\n", argv[0]);
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exit(1);
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}
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port = atoi(argv[1]);
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//设置SIGHLD的信号处理函数，用于收割结束的子进程
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Signal(SIGCHLD, sigchld_handler);
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listen_sock = open_listen_sock(port);
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if( listen_sock==-1) {
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printf("端口号%d繁忙\n",port);
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exit(1);
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}
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for(hit=1; ; hit++) {
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conn_sock = accept(listen_sock, (SA *) &clientaddr, &clientlen);
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/* determine the domain name and IP address of the client */
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hp = gethostbyaddr((const char *)&clientaddr.sin_addr.s_addr,
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sizeof(clientaddr.sin_addr.s_addr), AF_INET);
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haddrp = inet_ntoa(clientaddr.sin_addr);
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printf("server connected to %s (%s)\n", hp->h_name, haddrp);
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if (fork() == 0) {
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close(listen_sock); /* Child process closes its listening socket */
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toggle(conn_sock,hit); /* Child process services client */
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close(conn_sock); /* Child process closes connection with client */
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exit(0); /* Child process exits */
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}
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close(conn_sock); /* Parent closes connected socket (important!) */
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}
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}
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