C Language: freopen function(Reopen File)

In the C Programming Language, the freopen function first closes the file associated with stream. Then the freopen function opens filename and associates it with stream. In essence, it associates a different file to a stream that is already open.

Syntax

The syntax for the fopen function in the C Language is:




FILE *freopen(const char *filename, const char *mode, FILE *stream);



Parameters or Arguments

filename

The filename to associate with the file being reopened.

mode

The mode in which to open the file.

stream

The stream to associate with filename.

Returns

The freopen function returns a file pointer for the opened file. If the file can not be opened, the freopen function returns a null pointer.

Required Header

In the C Language, the required header for the freopen function is:




#include <stdio.h>



Applies To

In the C Language, the freopen function can be used in the following versions:

  • ANSI/ISO 9899-1990

stdio.h Functions





Instagram