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Constant Pointer:- It is type of pointer whose address cannot be modified after first time initialization. Ex:-  #include<stdio.h>    int main()    {        int var = 10, var2 = 20;        int *const ptr = &var;        ptr = &var2;                /* error cant change read only ptr is constant*/        *ptr = 30;                  /* value can be changed */        printf(“ptr  = %d\n”,*ptr);       return 0;   } In this program ptr is constant which cannot hold the other addresses but value can be modified. Pointer to a constant:- It is type of pointer in which the data  pointed cannot be modified. Ex:- #include<stdio.h>      int main()    {        int var = 10, var2 = 20;        const int* ptr = &var;        ptr = &var2;                /* can change the address */        *ptr = 30;                  /* error data is constant  */        printf(“ptr  = %d\n”,*ptr);       return 0;

#include<stdio.h> #include<string.h> #include<stdlib.h> #include<unistd.h> #include<errno.h> #include<arpa/inet.h> #include<netinet/in.h> #include<sys/socket.h> #include<sys/ioctl.h> #include<sys/types.h> #include<net/if.h> /** +++++++++++++++++++++++++++++++ Program:- Find IP address using ioctl +++++++++++++++++++++++++++++++ Author:- Surendra S.Patil +++++++++++++++++++++++++++++++ I/P:- interface name ex:- “eth0 “ +++++++++++++++++++++++++++++++ O/P:- Ip address (192.168.2.2) +++++++++++++++++++++++++++++++ */ int main() {   int sock_fd;   struct ifreq interface;   /* create socket and get socket descriptor */   sock_fd = socket(AF_INET,SOCK_DGRAM,0);  if (-1 == sock_fd) {   fprintf(stderr,”errno:- %d :- %s”,errno,strerror(errno));   exit(EXIT_FAILURE); }  /* copy the interface name */   strcpy(interface.ifr_name,”eth0″);  if(-1 == ioctl(sock_fd,SIOCGIFADDR,&interface)) {   fpr

1) How do you determine the size and range of the following data types ? char unsigned char short int unsigned int unsigned long float Ans:- limits.h header file defines the minimum and maximum range macros for each of the data types , sizeof(datatype) returns the number of bytes used by the datatype in current machine. 2) Write logical expressions that tests whether a given character variable c is lowercase letter uppercase letter digit white space(includes space,tab,newline) Ans:- lowercase letter = (c >= 'a' && c <= 'z') uppercase letter = (c >= 'A' && c <= 'Z') digit = (c >= '0' && c <= '9') white space(includes space,tab,newline) = (c == ' ' || c == '\t' || c == '\n') 3) Consider unsigned int val=0xCAFE; Write expressio

1. W hat do curly braces denote in C? Why does it make sense to use curly brac es to surround the body of a function?   Answer: The curly braces denote a block of code, in which variables can be declared. Variables declared within the block are valid only until the end of the block, marked by the matching right curly brace ’}’. The body of a function is one such type of block, and thus, curly braces are used to describe the extent of that block . 2.Describe the difference between the literal values 7, "7", and ’7 ’ ?   Answer: The first literal is integer 7.Second literal is null terminated string value '7'.Third literal is character '7' having ASCII character code (55). 3. Consider the statement double ans = 10.0+2.0/3.0−2.0∗2.0; Rewrite this statement, inserting parentheses to ensure that ans = 11.0 upon evaluation of this statement ? Answer: double ans = 10.0+2.0/ (( 3.0−2.0 ) ∗2.0 ) ; 4 .C

"Don't cry because it's over, smile because it happened." ― Dr. Seuss "How wonderful it is that nobody need wait a single moment before starting to improve the world." ― Anne Frank "The optimist proclaims that we live in the best of all possible worlds; and the pessimist fears this is true." ― James Branch Cabell Your time is limited, so don’t waste it living someone else’s life. –Steve Jobs Strive not to be a success, but rather to be of value. –Albert Einstein Life is 10% what happens to me and 90% of how I react to it. –John Maxwell If you do what you’ve always done, you’ll get what you’ve always gotten. –Tony Robbins The mind is everything. What you think you become.  –Buddha The best time to plant a tree was 20 years ago. The second best time is now. –Chinese Proverb An unexamined life is not worth living. –Socrates Eighty percent of success is showing up. –Woody Allen Don’t wait. The time will never be just right. –Napoleon Hill

Remove All Negative Influence Avoid negative influences . Even if it's a family member or close friend, we must not tolerate anyone's bad behavior. Steer clear from it so that it will not rub off on us.   Replace negative thoughts with positive ones . Look for a bright side in every situation. We will find that there are surprising benefits within them. If we do this long enough, it will become habitual, and it will make a tremendous difference in improving our positive thinking skills. Say "I can!" more than "I can't!" Remember, everything can be framed positively; make a relentless effort to do so.    Even when we don't get what we want, we gain valuable experience. Experiences are often much more valuable than material things. Material things slowly waste away; experiences stay with us, growing, our entire lives. There are both positive and negative aspects to most situations. We get to choose which ones we will focu