Programming and Data Structures by Pearson

420 Programming and Data Structures

Syntax

fp =fopen ( "d a ta . t x t " , "w ") ;

Here, data. txt is the file name and "w" is the mode.

2 . r (read) This mode opens a pre-existing file for reading. If the file doesn't exist, then compiler

returns NULL to the file pointer. Using pointer with i f statement we can prompt the user regarding

failure of operation.

Syntax

fp=fopen ("data.txt","r");

if (fp==NULL)

printf ("File does not exist");

OR

If (fp=(fopen ("data.txt","r"))==NULL)

printf ("File does not exist");

Here, data. dbf is opened for reading only. If the file does not exist the fopen () returns NULL to

file pointer x