C PROGRAMMING

DEFINING, OPENING AND CLOSING A FILE 

 

Defining a files

When working with files, you need to declare a pointer of type file. This declaration is needed for communication between the file and program.

example : FILE *fptr;

Opening a file - for creation and edit

Opening a file is performed using the library function in the "stdio.h" header file: fopen(). The syntax for opening a file in standard I/O is:

ptr = fopen("fileopen","mode") For Example:

fopen("E:\\cprogram\\newprogram.txt","w"); fopen("E:\\cprogram\\oldprogram.bin","rb");

• Let's suppose the file newrogram.txt doesn't exist in the location E:\\cprogram. The first function creates a new file named newprogram.txt and opens it for writing as per the mode 'w'.

The writing mode allows you to create and edit (overwrite) the contents of the file.

• Now let's suppose the second binary file oldprogram.bin exists in the location E:\\cprogram. The second function opens the existing file for reading in binary mode 'rb'. The reading mode only allows you to read the file, you cannot write into the file.

Closing a file

fclose(fptr);