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ch15/broad_recv.c

@@ -0,0 +1,55 @@
+#include <stdio.h>  
+#include <stdlib.h>  
+#include <string.h>  
+#include <unistd.h>  
+#include <arpa/inet.h>  
+#include <sys/socket.h>  
+
+#define BUF_SIZE    30
+
+void error_handling(char *message);  
+
+int main(int argc, char *argv[]){  
+    int recv_sock;
+    int str_len;
+    char buf[BUF_SIZE];  
+    struct sockaddr_in adr;
+
+    if(argc != 2){  
+        printf("Usage : %s <port>\n",argv[0]);  
+        exit(1);  
+    }  
+
+    recv_sock = socket(PF_INET,SOCK_DGRAM,0);  
+    if(recv_sock == -1){  
+        error_handling("socket() error");  
+    }  
+
+    memset(&adr,0,sizeof(adr));  
+    adr.sin_family=AF_INET;  
+    adr.sin_addr.s_addr=htonl(INADDR_ANY);	// ip  
+    adr.sin_port=htons(atoi(argv[1]));  //port
+
+    if(bind(recv_sock,(struct sockaddr *)&adr,sizeof(adr))==-1){
+	error_handling("bind error");
+    }
+
+    while(1){
+    	str_len = recvfrom(recv_sock,buf,BUF_SIZE-1,0,NULL,0);
+	if(str_len < 0){
+	    break;
+	}
+	buf[str_len] = 0;
+	fputs(buf,stdout);
+    }
+    close(recv_sock);
+
+    return 0;  
+}  
+
+void error_handling(char *message){  
+
+    fputs(message,stderr);  
+    fputs("\n",stderr);  
+    exit(1);  
+}  

ch15/broad_send.c

@@ -0,0 +1,55 @@
+#include <stdio.h>  
+#include <stdlib.h>  
+#include <string.h>  
+#include <unistd.h>  
+#include <arpa/inet.h>  
+#include <sys/socket.h>  
+
+#define BUF_SIZE    30
+
+void error_handling(char *message);  
+
+int main(int argc, char *argv[]){  
+    int send_sock;
+    FILE *fp;  
+    char buf[BUF_SIZE];  
+    struct sockaddr_in broad_adr;
+    int so_brd = 1;
+
+    if(argc != 3){  
+        printf("Usage : %s <group><port>\n",argv[0]);  
+        exit(1);  
+    }  
+
+    send_sock = socket(PF_INET,SOCK_DGRAM,0);  
+    if(send_sock == -1){  
+        error_handling("socket() error");  
+    }  
+
+    memset(&broad_adr,0,sizeof(broad_adr));  
+    broad_adr.sin_family=AF_INET;  
+    broad_adr.sin_addr.s_addr=inet_addr(argv[1]);	//ip  
+    broad_adr.sin_port=htons(atoi(argv[2]));  //port
+
+    setsockopt(send_sock,SOL_SOCKET,SO_BROADCAST,(void *)&so_brd,sizeof(so_brd));
+    if((fp = fopen("news.txt","r")) == NULL){
+  	error_handling("fopen");
+    }
+
+    while(!feof(fp)){
+	fgets(buf,BUF_SIZE,fp);
+	sendto(send_sock,buf,strlen(buf),0,(struct sockaddr *)&broad_adr,sizeof(broad_adr));
+	sleep(2);
+    }
+    fclose(fp);
+    close(send_sock);
+
+    return 0;  
+}  
+
+void error_handling(char *message){  
+
+    fputs(message,stderr);  
+    fputs("\n",stderr);  
+    exit(1);  
+}