Here is source code of the C program to illustrate reading of data from a file. The C program is successfully compiled and run on a Linux system. The program output is also shown below.
/*
* C program to illustrate how a file stored on the disk is read
*/
#include <stdio.h>
#include <stdlib.h>
void main()
{
FILE *fptr;
char filename[15];
char ch;
printf("Enter the filename to be opened \n");
scanf("%s", filename);
/* open the file for reading */
fptr = fopen(filename, "r");
if (fptr == NULL)
{
printf("Cannot open file \n");
exit(0);
}
ch = fgetc(fptr);
while (ch != EOF)
{
printf ("%c", ch);
ch = fgetc(fptr);
}
fclose(fptr);
}



$ cc pgm96.c
$ a.out
Enter the filename to be opened
pgm95.c
/*
* C program to create a file called emp.rec and store information
* about a person, in terms of his name, age and salary.
*/
#include <stdio.h>
void main()
{
FILE *fptr;
char name[20];
int age;
float salary;
fptr = fopen ("emp.rec", "w"); /* open for writing*/
if (fptr == NULL)
{
printf("File does not exists \n");
return;
}
printf("Enter the name \n");
scanf("%s", name);
fprintf(fptr, "Name = %s\n", name);
printf("Enter the age \n");
scanf("%d", &age);
fprintf(fptr, "Age = %d\n", age);
printf("Enter the salary \n");
scanf("%f", &salary);
fprintf(fptr, "Salary = %.2f\n", salary);
fclose(fptr);
}