C Programs during trng

1.  /*  Program 7 - ANYFILE.C */

#include <stdio.h>

#include <stdlib.h>

int main()

{

FILE *fp1;

char oneword[100], filename[25];

char *c;

   printf("Enter filename -> ");

   scanf("%s", filename);            /* read the desired filename  */

   fp1 = fopen(filename, "r");

   if (fp1 == NULL)

   {

      printf("File failed to open\n");

      exit (EXIT_FAILURE);

   }

   do 

   {

      c = fgets(oneword, 100, fp1);  /* get one line from the file */

      if (c != NULL)                

         printf("%s", oneword);      /* display it on the monitor  */

   } while (c != NULL);              /* repeat until NULL          */

   fclose(fp1);

   return EXIT_SUCCESS;

}

/* Result of execution

(The file selected is listed on the monitor)

*/

                             /*   Program 6 - BACKWARD.C */

#include <stdio.h>       /* Prototypes for standard Input/Output   */

#include <string.h>      /* Prototypes for string operations       */

void forward_and_backwards(char line_of_char[], int index);

int main()

{

char line_of_char[80];

int index = 0;

   strcpy(line_of_char, "This is a string.\n");

   forward_and_backwards(line_of_char, index);

   return 0;

}

void forward_and_backwards(char line_of_char[], int index)

{

   if (line_of_char[index]) 

   {

      printf("%c", line_of_char[index]);

      index++;

      forward_and_backwards(line_of_char, index);

   }

   printf("%c", line_of_char[index]);

}

/* Result of execution

This is a string.

.gnirts a si sih

*/

 /* Pointer*/

#include <stdio.h>

#include <string.h>

int main()

{

char strg[40], *there, one, two;

int  *pt, list[100], index;

   strcpy(strg, "This is a character string.");

   one = strg[0];                    /* one and two are identical */

   two = *strg;

   printf("The first output is %c %c\n", one, two);

   one = strg[8];                   /* one and two are indentical */

   two = *(strg+8);

   printf("The second output is %c %c\n", one, two);

   there = strg+10;          /* strg+10 is identical to &strg[10] */

   printf("The third output is %c\n", strg[10]);

   printf("The fourth output is %c\n", *there);

   for (index = 0 ; index < 100 ; index++)

      list[index] = index + 100;

   pt = list + 27;

   printf("The fifth output is %d\n", list[27]);

   printf("The sixth output is %d\n", *pt);

   return 0;

}

/* Result of execution

The first output is T T

The second output is a a

The third output is c

The fourth output is c

The fifth output is 127

The sixth output is 127

*/