IO非阻塞操作
sock的方法不一定非得是阻塞的,也可以非阻塞的操作。有两种方法分别为设置fcntl 和设置相应函数的参数。
服务端:
- #include <sys/socket.h>
- #include <stdio.h>
- #include <string.h>
- #include <netinet/in.h>
- #include <arpa/inet.h>
- #include <unistd.h>
- #include <stdlib.h>
- #include <errno.h>
- #define BUFSIZE 128
- int main(int argc,char *argv[]){
- int server_sockfd, client_sockfd;
- int server_len, client_len;
- struct sockaddr_in server_address;
- struct sockaddr_in client_address;
- int i,byte;
- char char_send[BUFSIZE];
- server_sockfd = socket(AF_INET, SOCK_STREAM, 0);
- bzero(&server_address, sizeof(server_address));
- server_address.sin_family = AF_INET;
- server_address.sin_port = htons(7838);
- server_address.sin_addr.s_addr = INADDR_ANY;
- server_len = sizeof(server_address);
- if ((bind(server_sockfd, (struct sockaddr *)&server_address, server_len))== -1) {
- perror("bind");
- exit(EXIT_FAILURE);
- }
- listen(server_sockfd, 5);
- printf("server waiting for connect\n");
- client_len = sizeof(client_address);
- client_sockfd = accept(server_sockfd,(struct sockaddr *)&client_address, (socklen_t *)&client_len);
- for(i=0;i<5;i++){
- memset(char_send,'\0',BUFSIZE);
- printf("input message to send:");
- fgets(char_send,BUFSIZE,stdin);
- if((byte=send(client_sockfd,char_send,strlen(char_send),0))==-1){
- perror("send");
- exit(EXIT_FAILURE);
- }
- memset(char_send,'\0',BUFSIZE);
- //最后一个参数为非阻塞的设置
- byte = recv(client_sockfd, char_send, BUFSIZE,MSG_DONTWAIT);
- if(byte > 0){
- printf("get %d message:%s", byte, char_send);
- byte=0;
- }else if(byte<0){
- if(errno==EAGAIN){
- errno=0;
- continue;
- }else{
- perror("recv");
- exit(EXIT_FAILURE);
- }
- }
- }
- shutdown(client_sockfd,2);
- shutdown(server_sockfd,2);
- }
#include <sys/socket.h> #include <stdio.h> #include <string.h> #include <netinet/in.h> #include <arpa/inet.h> #include <unistd.h> #include <stdlib.h> #include <errno.h> #define BUFSIZE 128 int main(int argc,char *argv[]){ int server_sockfd, client_sockfd; int server_len, client_len; struct sockaddr_in server_address; struct sockaddr_in client_address; int i,byte; char char_send[BUFSIZE]; server_sockfd = socket(AF_INET, SOCK_STREAM, 0); bzero(&server_address, sizeof(server_address)); server_address.sin_family = AF_INET; server_address.sin_port = htons(7838); server_address.sin_addr.s_addr = INADDR_ANY; server_len = sizeof(server_address); if ((bind(server_sockfd, (struct sockaddr *)&server_address, server_len))== -1) { perror("bind"); exit(EXIT_FAILURE); } listen(server_sockfd, 5); printf("server waiting for connect\n"); client_len = sizeof(client_address); client_sockfd = accept(server_sockfd,(struct sockaddr *)&client_address, (socklen_t *)&client_len); for(i=0;i<5;i++){ memset(char_send,'\0',BUFSIZE); printf("input message to send:"); fgets(char_send,BUFSIZE,stdin); if((byte=send(client_sockfd,char_send,strlen(char_send),0))==-1){ perror("send"); exit(EXIT_FAILURE); } memset(char_send,'\0',BUFSIZE); //最后一个参数为非阻塞的设置 byte = recv(client_sockfd, char_send, BUFSIZE,MSG_DONTWAIT); if(byte > 0){ printf("get %d message:%s", byte, char_send); byte=0; }else if(byte<0){ if(errno==EAGAIN){ errno=0; continue; }else{ perror("recv"); exit(EXIT_FAILURE); } } } shutdown(client_sockfd,2); shutdown(server_sockfd,2); }
客户端:
- #include <stdio.h>
- #include <string.h>
- #include <errno.h>
- #include <sys/socket.h>
- #include <resolv.h>
- #include <stdlib.h>
- #include <netinet/in.h>
- #include <arpa/inet.h>
- #include <unistd.h>
- #include <fcntl.h>
- #define MAXBUF 128
- int main(int argc, char **argv){
- int sockfd, ret, i;
- struct sockaddr_in dest, mine;
- char buffer[MAXBUF + 1];
- if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
- perror("Socket");
- exit(EXIT_FAILURE);
- }
- bzero(&dest, sizeof(dest));
- dest.sin_family = AF_INET;
- dest.sin_port = htons(7838);
- if(argc<2){
- printf("Usage: %s <dest ip> <src ip>",argv[0]);
- exit(1);
- }
- if (inet_aton(argv[1], (struct in_addr *) &dest.sin_addr.s_addr) == 0){
- perror(argv[1]);
- exit(1);
- }
- bzero(&mine, sizeof(mine));
- mine.sin_family = AF_INET;
- mine.sin_port = htons(7839);
- if (inet_aton(argv[2], (struct in_addr *) &mine.sin_addr.s_addr) == 0){
- perror(argv[2]);
- exit(EXIT_FAILURE);
- }
- if (bind(sockfd, (struct sockaddr *) &mine, sizeof(struct sockaddr)) == -1){
- perror(argv[3]);
- exit(EXIT_FAILURE);
- }
- printf("will connect!\n");
- if (connect(sockfd, (struct sockaddr *) &dest, sizeof(dest)) != 0) {
- perror("Connect ");
- exit(EXIT_FAILURE);
- }
- //设置sock连接的非阻塞
- if(fcntl(sockfd, F_SETFL, O_NONBLOCK) == -1) {
- perror("fcntl");
- exit(EXIT_FAILURE);
- }
- while(1){
- bzero(buffer, MAXBUF + 1);
- //因为在socket中设置过,所以就不用再设置了
- ret = recv(sockfd, buffer, MAXBUF, 0);
- if(ret > 0){
- printf("get %d message:%s", ret, buffer);
- ret=0;
- }else if(ret < 0) {
- if(errno == EAGAIN) {
- errno=0;
- continue;
- }else{
- perror("recv");
- exit(EXIT_FAILURE);
- }
- }
- memset( buffer,'\0',MAXBUF+1);
- printf("input message to send:");
- fgets( buffer,MAXBUF,stdin);
- if((ret=send(sockfd,buffer,strlen(buffer),0))==-1){
- perror("send");
- exit(EXIT_FAILURE);
- }
- }
- close(sockfd);
- return 0;
- }
#include <stdio.h> #include <string.h> #include <errno.h> #include <sys/socket.h> #include <resolv.h> #include <stdlib.h> #include <netinet/in.h> #include <arpa/inet.h> #include <unistd.h> #include <fcntl.h> #define MAXBUF 128 int main(int argc, char **argv){ int sockfd, ret, i; struct sockaddr_in dest, mine; char buffer[MAXBUF + 1]; if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) { perror("Socket"); exit(EXIT_FAILURE); } bzero(&dest, sizeof(dest)); dest.sin_family = AF_INET; dest.sin_port = htons(7838); if(argc<2){ printf("Usage: %s <dest ip> <src ip>",argv[0]); exit(1); } if (inet_aton(argv[1], (struct in_addr *) &dest.sin_addr.s_addr) == 0){ perror(argv[1]); exit(1); } bzero(&mine, sizeof(mine)); mine.sin_family = AF_INET; mine.sin_port = htons(7839); if (inet_aton(argv[2], (struct in_addr *) &mine.sin_addr.s_addr) == 0){ perror(argv[2]); exit(EXIT_FAILURE); } if (bind(sockfd, (struct sockaddr *) &mine, sizeof(struct sockaddr)) == -1){ perror(argv[3]); exit(EXIT_FAILURE); } printf("will connect!\n"); if (connect(sockfd, (struct sockaddr *) &dest, sizeof(dest)) != 0) { perror("Connect "); exit(EXIT_FAILURE); } //设置sock连接的非阻塞 if(fcntl(sockfd, F_SETFL, O_NONBLOCK) == -1) { perror("fcntl"); exit(EXIT_FAILURE); } while(1){ bzero(buffer, MAXBUF + 1); //因为在socket中设置过,所以就不用再设置了 ret = recv(sockfd, buffer, MAXBUF, 0); if(ret > 0){ printf("get %d message:%s", ret, buffer); ret=0; }else if(ret < 0) { if(errno == EAGAIN) { errno=0; continue; }else{ perror("recv"); exit(EXIT_FAILURE); } } memset( buffer,'\0',MAXBUF+1); printf("input message to send:"); fgets( buffer,MAXBUF,stdin); if((ret=send(sockfd,buffer,strlen(buffer),0))==-1){ perror("send"); exit(EXIT_FAILURE); } } close(sockfd); return 0; }
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