1.并发服务器与客户端 （UDP）
1 //client.c 2 #include <stdio.h> 3 #include <stdlib.h> 4 #include <string.h> 5 #include <unistd.h> 6 #include <netinet/in.h> 7 #include <fcntl.h> 8 9 #define MAX 10 10 #define MAXLINE 18 11 #define SERV_PORT 8000 12 13 int main(int argc, char *argv[]) 14 { 15 struct sockaddr_in servaddr; 16 int sockfd = 0, n = 0, number = 0; 17 char buf[MAXLINE] = {0}; 18 char str[INET_ADDRSTRLEN] = {0}; 19 char find[MAXLINE] = {0}; 20 socklen_t servaddr_len; 21 int len = 0, fr = 0, fw = 0, data_len = 0, read_len = 0; 22 23 sockfd = socket(AF_INET, SOCK_DGRAM, 0); 24 25 bzero(&servaddr, sizeof(servaddr)); 26 servaddr.sin_family = AF_INET; 27 inet_pton(AF_INET, argv[1], &servaddr.sin_addr); 28 servaddr.sin_port = htons(SERV_PORT); 29 30 while((fgets(buf, MAXLINE, stdin) != NULL)) 31 { 32 if('\n' == buf[strlen(buf) - 1]) { 33 buf[strlen(buf) - 1] = '\0'; 34 } 35 36 int fr = open(buf, O_RDONLY); 37 bzero(find, sizeof(find)); 38 len = strlen(buf); 39 number = -1; 40 //*((int *)(find + 0)) = number; 41 memcpy(find, &number, 4); 42 memcpy(&find[4], &len, 4); 43 memcpy(&find[8], buf, len); 44 n = sendto(sockfd, find, MAXLINE, 0, (struct sockaddr *)&servaddr, sizeof(servaddr)); 45 if(-1 == n) { 46 perror("sendto"); 47 exit(1); 48 } 49 int i = 0; 50 for(i = 0; i != MAXLINE; i ++) 51 { 52 printf("%x", find[i]); 53 } 54 printf("\n"); 55 56 n = recvfrom(sockfd, &fw, 4, 0, NULL, 0); 57 printf("fw = %d\n", fw); 58 //--------------------------------------------------------- 59 data_len = lseek(fr, 0, SEEK_END); 60 lseek(fr, 0, SEEK_SET); 61 printf("data_len = %d\n", data_len); 62 //========================================================== 63 while(data_len > 0) 64 { 65 bzero(find, sizeof(find)); 66 //bzero(buf, sizeof(buf)); 67 //memcpy(find, &fr, 4); 68 *((int *)(find)) = fw; 69 if(data_len < MAX) { 70 read_len = read(fr, buf, data_len); 71 //memcpy(&find[4], &read_len, 4); 72 *((int *)(find + 4)) = read_len; 73 memcpy(&find[8], buf, read_len); 74 } 75 else { 76 read_len = read(fr, buf, MAX); 77 //memcpy(&find[4], (char *)MAX, 4); 78 *((int *)(find + 4)) = MAX; 79 memcpy(&find[8], buf, MAX); 80 } 81 printf("read_len = %d\n", read_len); 82 printf("%s\n", &find[8]); 83 n = sendto(sockfd, find, MAXLINE, 0, (struct sockaddr *)&servaddr, sizeof(servaddr)); 84 data_len -= read_len; 85 printf("%d = data_len\n", data_len); 86 } 87 //=============================================================== 88 bzero(find, sizeof(find)); 89 *((int *)(find)) = fw; 90 n = sendto(sockfd, find, MAXLINE, 0, (struct sockaddr *)&servaddr, sizeof(servaddr)); 91 //====================================================================================== 92 bzero(buf, sizeof(buf)); 93 close(fr); 94 #if 0 95 n = recvfrom(sockfd, find, MAXLINE, 0, NULL, 0); 96 if(-1 == n) { 97 perror("recvform error"); 98 exit(1); 99 } 100 write(STDOUT_FILENO, find, n); 101 #endif 102 } 103 104 close(sockfd); 105 106 return 0; 107 }
1 //server.c 2 #include <stdio.h> 3 #include <stdlib.h> 4 #include <string.h> 5 #include <fcntl.h> 6 #include <netinet/in.h> 7 8 #define MAX 10 9 #define MAXLINE 18 10 #define SERV_PORT 8000 11 12 int main(int argc, char *argv[]) 13 { 14 struct sockaddr_in servaddr, cliaddr; 15 socklen_t cliaddr_len; 16 int sockfd = 0; 17 char buf[MAXLINE] = {0}; 18 char itemp[MAXLINE] = {0}; 19 char filename[MAX] = {0}; 20 char str[INET_ADDRSTRLEN] = {0}; 21 int i = 0, n = 0, file_len = 0, data_len = 0, fw = 0, write_len = 0, f_get = 0; 22 23 sockfd = socket(AF_INET, SOCK_DGRAM, 0); 24 25 bzero(&servaddr, sizeof(servaddr)); 26 servaddr.sin_family = AF_INET; 27 servaddr.sin_addr.s_addr = htonl(INADDR_ANY); 28 servaddr.sin_port = htons(SERV_PORT); 29 30 bind(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)); 31 32 printf("Accepting connections ...\n"); 33 cliaddr_len = sizeof(cliaddr); 34 35 while(1) 36 { 37 //-------------------------------------------------- 38 bzero(buf, sizeof(buf)); 39 n = recvfrom(sockfd, buf, MAXLINE, 0, (struct sockaddr *)&cliaddr, &cliaddr_len); 40 printf("received from %s at PORT %d\n", (char *)inet_ntop(AF_INET, &cliaddr.sin_addr, str, sizeof(str)), ntohs(cliaddr.sin_port)); 41 if(-1 == n) { 42 perror("recvfrom error"); 43 exit(1); 44 } 45 f_get = *((int *)(buf)); 46 printf("fw == %d\n", f_get); 47 if(-1 == f_get) { 48 memcpy(&file_len, &buf[4], 4); 49 printf("filename_len = %d\n", file_len); 50 memcpy(filename, &buf[8], file_len); 51 printf("filename = %s\n", filename); 52 fw = open(filename, O_WRONLY | O_TRUNC | O_CREAT, 0644); 53 if(fw < 0) { 54 perror("open fw"); 55 exit(1); 56 } 57 n = sendto(sockfd, &fw, 4, 0, (struct sockaddr *)&cliaddr, sizeof(cliaddr)); 58 } 59 else if(f_get == fw){ 60 write_len = *((int *)(buf + 4)); 61 printf("%d\n", write_len); 62 if(0 == write_len) { 63 close(f_get); 64 } 65 else { 66 write(f_get, &buf[8], write_len); 67 } 68 } 69 bzero(filename, sizeof(filename)); 70 bzero(buf, sizeof(buf)); 71 } 72 73 return 0; 74 }
2.函数原型 ： #include <sys/socket.h> #include <sys/types.h>
ssize_t sendto(int sockfd, const void *buf, size_t len, int flags, const struct sockaddr *dest_addr, socklen_t addrlen); //发送数据报
ssize_t recvfrom(int sockfd, void *buf, size_t len, int flags, struct sockaddr *src_addr, socklen_t *addrlen); //接受数据报
