_set_fmode

Article
06/05/2017

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The latest version of this topic can be found at _set_fmode.

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

Syntax

errno_t _set_fmode(   
   int mode   
);

Parameters

[in] mode
The file translation mode desired: _O_TEXT or _O_BINARY.

Return Value

Returns zero if successful, an error code on failure. If mode is not _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.

Requirements

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

For more compatibility information, see Compatibility in the Introduction.

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  
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