set-fmode.md

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Learn more about: _set_fmode	_set_fmode	4/2/2020	_set_fmode _o__set_fmode	msvcrt.dll msvcr80.dll msvcr90.dll msvcr100.dll msvcr100_clr0400.dll msvcr110.dll msvcr110_clr0400.dll msvcr120.dll msvcr120_clr0400.dll ucrtbase.dll api-ms-win-crt-stdio-l1-1-0.dll	DLLExport	apiref	_set_fmode set_fmode	file translation [C++], default mode _set_fmode function file translation [C++], setting mode set_fmode function	f80eb9c7-733b-4652-a9bc-6b3790a35f12

_set_fmode

Sets the default file translation mode for file I/O operations.

Syntax

errno_t _set_fmode(
   int mode
);

Parameters

mode
The file translation mode desired: _O_TEXT or _O_BINARY.

Return value

Returns zero if successful, an error code on failure. If mode isn't _O_TEXT or _O_BINARY or _O_WTEXT, the invalid parameter handler is invoked, as described in Parameter validation. If execution is allowed to continue, this function sets errno to EINVAL and returns EINVAL.

Remarks

The function sets the _fmode global variable. This variable specifies the default file translation mode for the file I/O operations _open and _pipe.

_O_TEXT and _O_BINARY are defined in Fcntl.h. EINVAL is defined in Errno.h.

By default, this function's global state is scoped to the application. To change this behavior, see Global state in the CRT.

Requirements

Routine	Required header	Optional header
_set_fmode	<stdlib.h>	<fcntl.h>, <errno.h>

For more compatibility information, see Compatibility.

Example

// crt_set_fmode.c
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>     /* for _O_TEXT and _O_BINARY */
#include <errno.h>     /* for EINVAL */
#include <sys\stat.h>  /* for _S_IWRITE */
#include <share.h>     /* for _SH_DENYNO */

int main()
{
   int mode, fd, ret;
   errno_t err;
   int buf[12] = { 65, 66, 67, 68, 69, 70, 71, 72, 73, 74,
                   75, 76 };
   char * filename = "fmode.out";

   err = _get_fmode(&mode);
   if (err == EINVAL)
   {
      printf( "Invalid parameter: mode\n");
      return 1;
   }
   else
      printf( "Default Mode is %s\n", mode == _O_TEXT ? "text" :
              "binary");

   err = _set_fmode(_O_BINARY);
   if (err == EINVAL)
   {
      printf( "Invalid mode.\n");
      return 1;
   }

   if ( _sopen_s(&fd, filename, _O_RDWR | _O_CREAT, _SH_DENYNO, _S_IWRITE | _S_IREAD) != 0 )
   {
      printf( "Error opening the file %s\n", filename);
      return 1;
   }

   if (ret = _write(fd, buf, 12*sizeof(int)) < 12*sizeof(int))
   {
      printf( "Problem writing to the file %s.\n", filename);
      printf( "Number of bytes written: %d\n", ret);
   }

   if (_close(fd) != 0)
   {
      printf("Error closing the file %s. Error code %d.\n",
             filename, errno);
   }

   system("type fmode.out");
}

Default Mode is binary
A   B   C   D   E   F   G   H   I   J   K   L

See also

_fmode
_get_fmode
_setmode
Text and binary mode file I/O