6.23.11 fwide Function

Sets and determines the width orientation of a stream.

Include

<wchar.h>

Prototype

int fwide(FILE * stream, int mode);

Arguments

stream

the stream to write to

mode

the stream orientation to set

Return Value

The function returns a positive value if, after the call, the stream has wide orientation, a negative value if the stream has byte orientation, or zero if the stream has no orientation.

Remarks

For positive values of mode, the function attempts to make the stream wide oriented; for negative values, it attempts to make the stream byte oriented. For a mode of zero, the orientation of the stream is not altered. Once a stream has been oriented, subsequent calls to fwide() do not change that stream's orientation.

Example

#include <wchar.h>
#include <stdio.h>

void prStrOrient(int orientation)
{
  if (orientation > 0)
    puts("The stream is wide oriented");
  else if (orientation < 0)
    puts("The stream is byte oriented");
  else
    puts("The stream is not oriented");
}

int main(void)
{
  FILE * myfile;
  int ret;

  if ((myfile = fopen("afile", "w")) == NULL)
    wprintf(L"Cannot open afile\n");
  else {
    ret = fwide(myfile, 0);
    prStrOrient(ret);
    ret = fwide(myfile, 1);     // set wide orientation
    prStrOrient(ret);
    ret = fwide(myfile, -1);    // no further changes made
    prStrOrient(ret);
    fclose (myfile);
  }
}

Example Output

Content of afile.

The stream is not oriented
The stream is wide oriented
The stream is wide oriented