This program demonstrates various C file I/O and standard input/output operations while using constants and basic arithmetic. It reads from ../Input.txt and writes processed content to ../Output.txt.

Purpose: Illustrates file I/O, standard input/output, and string/character processing. How It Works: File Handling:

Opens ../Input.txt for reading and ../Output.txt for writing. Handles file opening errors with error messages. Standard Input/Output:

Reads an integer, a character, and a string from the user. Outputs them using printf, putchar, and puts. Casting and Arithmetic:

Performs a calculation involving a constant (PINUMBER) and user input, demonstrating type casting. File Copying:

Character-by-Character Copy: Uses fgetc to read characters and fputc to write them to ../Output.txt. Line-by-Line Copy: Uses fgets to read and fputs to write lines, appending newlines for clarity. Word-by-Word Copy: Reads words with fscanf and writes them using fprintf. Rewind:

Resets the file pointer to the beginning of the input file before each new operation.