added more codes

miscellaneous/address-conversion.c

@@ -0,0 +1,41 @@
+#include<stdio.h>
+#include<sys/socket.h>
+#include<stdlib.h>
+#include<arpa/inet.h>
+
+#define SERV_PORT 9002
+
+int main()
+{
+
+  char str[INET_ADDRSTRLEN],*str1,*str2;
+  struct sockaddr_in server;
+  //server.sin_port=SERV_PORT;
+
+  // store this IP address in server:
+  printf("Testing inet_pton and inet inet_ntop\n");
+  inet_pton(AF_INET, "192.0.2.33", &(server.sin_addr));
+  // now get it back and print it
+  inet_ntop(AF_INET, &(server.sin_addr), str, INET_ADDRSTRLEN);
+  printf("%s\n", str); // prints "192.0.2.33"
+
+  bzero(&str1,sizeof(str1));
+  bzero(&server,sizeof(server));
+  printf("Testing inet_ntoa and inet_aton\n");
+
+  inet_aton("192.168.1.1",&(server.sin_addr));
+  str1=inet_ntoa(server.sin_addr);
+  printf("%s\n",str1);
+
+
+  bzero(&str1,sizeof(str1));
+  bzero(&server,sizeof(server));
+  printf("Testing inet_addr\n");
+
+  server.sin_addr.s_addr=inet_addr("192.2.2.2");
+  str2=inet_ntoa(server.sin_addr);
+  printf("%s\n",str2);
+
+
+}
+

miscellaneous/host-byte-order.c

@@ -0,0 +1,35 @@
+#include<stdio.h>
+#include<stdlib.h>
+
+#define CPU_VENDOR_OS "intel-gnu-linux"
+
+int main()
+{
+	union
+	{
+		short s;
+		char c[sizeof(short)];
+	}un;
+	un.s=0x0102;
+	printf("%s\n",CPU_VENDOR_OS);
+	if(sizeof(short)==2)
+	{
+		if(un.c[0]==1 && un.c[1]==2)
+		{
+			printf("Big endian\n");
+		}
+		else if(un.c[0]==2 && un.c[1]==1)
+		{
+			printf("Little endian\n");
+		}
+		else 
+		{
+			 printf("Unknown\n");
+		}	
+	}
+	else
+	{
+		printf("sizeof(short) = %lu",sizeof(short));
+	}		
+	return 0;
+}

miscellaneous/sigint.c

@@ -0,0 +1,25 @@
+#include <stdio.h>
+#include <signal.h>
+
+/* Signal Handler for SIGINT */
+void sigintHandler(int sig_num)
+{
+    // Reset handler to catch SIGINT next time.
+
+    signal(SIGINT, sigintHandler);
+    printf("\n Cannot be terminated using Ctrl+C \n");
+    fflush(stdout);
+}
+
+int main ()
+{
+    // Set the SIGINT (Ctrl-C) signal handler to sigintHandler 
+
+    signal(SIGINT, sigintHandler);
+
+    /* Infinite loop */
+    while(1)
+    {        
+    }
+    return 0;
+}

udp/udp-echo-connected/connected-udp-client.c

@@ -0,0 +1,49 @@
+#include<stdio.h>
+#include<arpa/inet.h>
+#include<sys/socket.h>
+#include<string.h>
+
+#define SERV_PORT 9002
+#define SERV_IP "127.0.0.1"
+#define MAX 1001
+
+
+void dg_cli(int sockfd,struct sockaddr* server,socklen_t serv_len)
+{
+
+	int n;
+	char sendline[MAX],recvline[MAX+1];
+	connect(sockfd,server,serv_len);
+	while(fgets(sendline,MAX,stdin)!=NULL)
+    {
+    	write(sockfd,sendline,strlen(sendline));
+    	n=read(sockfd,recvline,MAX);
+    	recvline[n]=0;
+    	fputs(recvline,stdout);
+    	bzero(recvline,sizeof(recvline));
+	    bzero(sendline,sizeof(sendline));
+    }		
+}
+
+
+int main()
+{
+	int connfd,listenfd;
+	struct sockaddr_in server,client;
+	socklen_t len;
+
+	listenfd=socket(AF_INET,SOCK_DGRAM,0);
+
+    bzero(&server,sizeof(server));
+
+    server.sin_family=AF_INET;
+    server.sin_port=htons(SERV_PORT);
+    server.sin_addr.s_addr=inet_addr(SERV_IP);
+
+    len=sizeof(server);
+
+     dg_cli(listenfd,(struct sockaddr*)&server,len);
+
+
+   return 0;
+}

udp/udp-echo-connected/connected-udp-server.c

@@ -0,0 +1,52 @@
+#include<stdio.h>
+#include<sys/socket.h>
+#include<arpa/inet.h>
+#include<string.h>
+#include<error.h>
+#include<netinet/in.h>
+
+
+#define SERV_PORT 9002
+#define SERV_IP "127.0.0.1"
+#define MAXLINE 1001
+#define MAX 1001
+
+int main()
+{
+	struct sockaddr_in server,client;
+	socklen_t clilen;
+	int listenfd,sockfd,n;
+    char buff[MAXLINE];
+
+	listenfd=socket(AF_INET,SOCK_DGRAM,0);
+
+	bzero(&server,sizeof(server));
+	server.sin_family=AF_INET;
+	server.sin_addr.s_addr=inet_addr(SERV_IP);
+	server.sin_port=htons(SERV_PORT);
+
+	if((bind(listenfd,(struct sockaddr*)&server,sizeof(server)))<0)
+     {
+     	perror("Bind failed");
+     }
+     else
+     {
+     	printf("Bind successful \n");
+     } 
+
+    clilen=sizeof(client);
+
+
+   for(;;)
+   {
+      //printf("Entering loop");
+      clilen=sizeof(client);
+      n=recvfrom(listenfd,buff,MAXLINE,0,(struct sockaddr*)&client,&clilen);
+      sendto(listenfd,buff,n,0,(struct sockaddr*)&client,clilen);
+      buff[n]=0;
+      printf("Recd %s from client\n",buff);
+
+    }
+
+
+}