Re-direct a stream to another file.

This function is compatible with the following targets:

ANSI

BeOS

EMB/RTOS

Mac OS

Palm OS

Win32

#include <stdio.h>

FILE *freopen(const char *filename, 

Parameters for this facility are:

filename	const char *	The name of the file to re-open
mode	const char *	The file opening mode
stream	FILE *	A pointer to a FILE stream

The freopen() function changes the file stream is associated with to another file. The function first closes the file the stream is associated with, and opens the new file, filename, with the specified mode, using the same stream.

fopen() returns the value of stream, if it is successful. If fopen() fails it returns a null pointer (NULL).

"fopen"

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
	FILE *f;

	// re-direct output from the console to a new file
	if (( f = freopen("newstdout", "w+", stdout)) == NULL) {
		printf("Can't create new stdout file.\n");
		exit(1);
	}
	printf("If all goes well, this text should be in\n");
	printf("a text file, not on the screen via stdout.\n");
	fclose(f);

	return 0;
}