Issue #40 IP Lookup using getopt

datastructs/ringbuffer/ring.h

@@ -2,9 +2,9 @@
 #define RING_H
 
 /* A ring buffer for multi-threaded programs. A single producer pushes
- * objects into the ring, while a single consumer pops them off for
- * processing. If the ring is full (i.e., the consumer is slower than the
- * producer), then the push operation fails.
+* objects into the ring, while a single consumer pops them off for
+* processing. If the ring is full (i.e., the consumer is slower than the
+* producer), then the push operation fails.
 */
 
 struct ring
@@ -18,16 +18,16 @@ struct ring
 
 
 /* Create a ring buffer with the specified size. Return the ring or NULL
-   if there is not enough memory to create. */
+if there is not enough memory to create. */
 struct ring* ring_create(int size);
 
 /* Add an entry to the ring.
-        Return 0 on success, or a sensible error code if ring is full
+Return 0 on success, or a sensible error code if ring is full
 */
 int ring_push(struct ring *rb, void* data);
 
 /* Remove an entry from the ring.
-        Return a pointer to the data, or NULL if empty
+Return a pointer to the data, or NULL if empty
 */
 void* ring_pop(struct ring *rb);
 

datastructs/ringbuffer/test/ring_test.c

@@ -9,7 +9,7 @@ with exceeding push and pop options
 
 #include "../ring.h"
 
-int
+	int
 main()
 {
 	//set buffer size as 5, first push 3 elements, and then pop 2 elements, then push 6 elements, at last pop 12 elements

sockets/iplookup.c

@@ -2,73 +2,77 @@
 #include <stdio.h>
 #include <string.h>
 #include <sys/socket.h>
+#include <unistd.h>
 #include <errno.h>
 #include <netdb.h>
 #include <arpa/inet.h>
 
 int main(int argc , char *argv[])
 {
 	int sockfd;
+	struct addrinfo *res = 0; //Setting addrinfo struct for getaddrinfo.
 	struct addrinfo hints, *servinfo, *p;
 	struct sockaddr_in *h;
+	char *hostname = malloc(sizeof(char) * 1000), *ip = malloc(sizeof(char) * 100);;
 	int rc, ctr;
-	
+
 	//if argc size is less than 2, then the hostname was not included as a command line input.	
 	if(argc <3){
 		printf("Error: Missing Hostname/IP Address or flag to decide IP->Hostname or Hostname->IP\n");
 		exit(1);
 	}
 	//if command line input is "-h", then hostname was given.
-	if (strcmp(argv[1], "-h") == 0) {
-		char *hostname = argv[2]; //hostname from command line input.
-    		char ip[100]; 		  //set up to take in the IPv4 address later.
+	int o;
+       while((o = getopt (argc, argv, "h:i:")) != -1){
+		switch(o){
+			case 'h':
+				hostname = optarg; //hostname from command line input.
+
+				memset(&hints, 0, sizeof hints); //setting space for hints.
+				hints.ai_family = AF_INET;	 //setting the family type to IPv4 only.
+				hints.ai_socktype = SOCK_STREAM; //setting socket type to streams.
+
+				//if the return value is not zero, there is an error.
+				if((rc = getaddrinfo(hostname, "http", &hints, &servinfo)) != 0)
+				{
+					perror(gai_strerror(rc)); //print the error. gai_strerror translates the error to readable human text.
+					exit(-1);
+				}
+
+				ctr = 1;
+				//find the first connection from the results
+				for(p = servinfo; p != NULL; p = p->ai_next)
+				{
+					h = (struct sockaddr_in *) p->ai_addr; //set h to the pointer of the sockaddr struct. ai_addr is a pointer to a filled-in socket address struct.
+					strcpy(ip, inet_ntoa(h->sin_addr)); //sin_addr holds the IPv4 address. this is copied to ip.
+					printf("%s - IPv4 address #%d: %s\n" ,hostname , ctr, ip);
+					ctr++;
+				}
+				break;
 
-    		memset(&hints, 0, sizeof hints); //setting space for hints.
-    		hints.ai_family = AF_INET;	 //setting the family type to IPv4 only.
-    		hints.ai_socktype = SOCK_STREAM; //setting socket type to streams.
-
-    		//if the return value is not zero, there is an error.
-    		if((rc = getaddrinfo(hostname, "http", &hints, &servinfo)) != 0)
-    		{
-    			perror(gai_strerror(rc)); //print the error. gai_strerror translates the error to readable human text.
-    			exit(-1);
-    		}
-
-        	ctr = 1;
-    		//find the first connection from the results
-    		for(p = servinfo; p != NULL; p = p->ai_next)
-    		{
-    			h = (struct sockaddr_in *) p->ai_addr; //set h to the pointer of the sockaddr struct. ai_addr is a pointer to a filled-in socket address struct.
-    			strcpy(ip, inet_ntoa(h->sin_addr)); //sin_addr holds the IPv4 address. this is copied to ip.
-        	    printf("%s - IPv4 address #%d: %s\n" ,hostname , ctr, ip);
-        	    ctr++;
-    		}
+			case 'i':
+
+				ip = optarg;     //command line input
+				printf("Command line input: %s\n", ip); //output to show user their input.
 
-    	}
-    	//otherwise, if command line input is "-i", then IPv4 address was given.
-	else if(strcmp(argv[1], "-i") == 0){
-		struct addrinfo *res=0; //Setting addrinfo struct for getaddrinfo.
-		int rc;             //used for error-checking later on.
-
-        	char *ip = argv[2];     //command line input
-    		char hostname[1000];     //variable to store output
-        	printf("Command line input: %s\n", ip); //output to show user their input.
-
-        	rc = getaddrinfo(ip, 0, 0, &res);   //getaddrinfo is used to supply parameters to getnameinfo.
-        	//error checking getaddrinfo.
-        	if(rc != 0)
-    		{
-    			perror(gai_strerror(rc)); //print the error. gai_strerror translates the error to readable human text.
-    			exit(-1);
-    		}
-
-		rc = getnameinfo(res->ai_addr, res->ai_addrlen, hostname, 1000, 0, 0, 0);
-        	//error checking getnameinfo.
-        	if(rc != 0)
-    		{
-    			perror(gai_strerror(rc)); //print the error. gai_strerror translates the error to readable human text.
-    			exit(-1);
-    		}
-        	printf("Hostname found: %s\n", hostname);
-    	}
+				rc = getaddrinfo(ip, 0, 0, &res);   //getaddrinfo is used to supply parameters to getnameinfo.
+				//error checking getaddrinfo.
+				if(rc != 0)
+				{
+					perror(gai_strerror(rc)); //print the error. gai_strerror translates the error to readable human text.
+					exit(-1);
+				}
+
+				rc = getnameinfo(res->ai_addr, res->ai_addrlen, hostname, 1000, 0, 0, 0);
+				//error checking getnameinfo.
+				if(rc != 0)
+				{
+					perror(gai_strerror(rc)); //print the error. gai_strerror translates the error to readable human text.
+					exit(-1);
+				}
+				printf("Hostname found: %s\n", hostname);
+				break;
+
+		}
+	}
 }