sortix--sortix/libc/stdio/freopen.c

/*
 * Copyright (c) 2013, 2015 Jonas 'Sortie' Termansen.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * stdio/freopen.c
 * Changes the file with which a FILE is associated.
 */

#include <errno.h>
#include <stdio.h>

#include "fdio.h"

FILE* freopen(const char* path, const char* mode, FILE* fp)
{
	if ( !path )
		return errno = EBADF, (FILE*) NULL;

	// Uninstall the current backend of the FILE (after flushing) and return the
	// FILE to the default state (like a new object from fnewfile).
	fshutdown(fp);

	// Attempt to open the new path and install that into our FILE object.
	if ( !fdio_install_path(fp, path, mode) )
	{
		fclose(fp);
		return NULL;
	}

	return fp;
}