file-translation-constants.md

description	title	ms.date	helpviewer_keywords	ms.assetid
Learn more about: File Translation Constants	File Translation Constants	11/04/2016	translation constants file translation [C++], constants translation, file translation constants translation, constants constants [C++], file translation mode file translation [C++]	49b13bf3-442e-4d19-878b-bd1029fa666a

File Translation Constants

Syntax

#include <stdio.h>

Remarks

These constants specify the mode of translation ("b" or "t"). The mode is included in the string specifying the type of access ("r", "w", "a", "r+", "w+", "a+").

The translation modes are as follows:

• t

  Opens in text (translated) mode. In this mode, carriage return-line feed (CR-LF) combinations are translated into single line feeds (LF) on input, and LF characters are translated into CR-LF combinations on output. Also, CTRL+Z is interpreted as an end-of-file character on input. In files opened for reading or reading and writing, fopen checks for CTRL+Z at the end of the file and removes it, if possible. This is done because using the fseek and ftell functions to move within a file ending with CTRL+Z may cause fseek to behave improperly near the end of the file.

  [!NOTE] The t option is not part of the ANSI standard for fopen and freopen. It is a Microsoft extension and should not be used where ANSI portability is desired.

• b

  Opens in binary (untranslated) mode. The above translations are suppressed.

If t or b is not given in mode, the translation mode is defined by the default-mode variable _fmode. For more information about using text and binary modes, see Text and Binary Mode File I/O.

See also

_fdopen, _wfdopen
fopen, _wfopen
freopen, _wfreopen
_fsopen, _wfsopen
Global Constants