77 lines
1.9 KiB
C
77 lines
1.9 KiB
C
/*
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FUNCTION
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<<fwide>>---set and determine the orientation of a FILE stream
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INDEX
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fwide
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INDEX
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_fwide_r
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SYNOPSIS
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#include <wchar.h>
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int fwide(FILE *<[fp]>, int <[mode]>);
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int _fwide_r(struct _reent *<[ptr]>, FILE *<[fp]>, int <[mode]>);
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DESCRIPTION
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When <[mode]> is zero, the <<fwide>> function determines the current
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orientation of <[fp]>. It returns a value > 0 if <[fp]> is
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wide-character oriented, i.e. if wide character I/O is permitted but
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char I/O is disallowed. It returns a value < 0 if <[fp]> is byte
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oriented, i.e. if char I/O is permitted but wide character I/O is
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disallowed. It returns zero if <[fp]> has no orientation yet; in
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this case the next I/O operation might change the orientation (to byte
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oriented if it is a char I/O operation, or to wide-character oriented
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if it is a wide character I/O operation).
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Once a stream has an orientation, it cannot be changed and persists
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until the stream is closed, unless the stream is re-opened with freopen,
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which removes the orientation of the stream.
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When <[mode]> is non-zero, the <<fwide>> function first attempts to set
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<[fp]>'s orientation (to wide-character oriented if <[mode]> > 0, or to
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byte oriented if <[mode]> < 0). It then returns a value denoting the
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current orientation, as above.
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RETURNS
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The <<fwide>> function returns <[fp]>'s orientation, after possibly
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changing it. A return value > 0 means wide-character oriented. A return
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value < 0 means byte oriented. A return value of zero means undecided.
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PORTABILITY
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C99, POSIX.1-2001.
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*/
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#include <_ansi.h>
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#include <wchar.h>
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#include "local.h"
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int
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_fwide_r (struct _reent *ptr,
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FILE *fp,
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int mode)
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{
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int ret;
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CHECK_INIT(ptr, fp);
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_newlib_flockfile_start (fp);
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if (mode != 0) {
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(void) ORIENT (fp, mode);
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}
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if (!(fp->_flags & __SORD))
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ret = 0;
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else
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ret = (fp->_flags2 & __SWID) ? 1 : -1;
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_newlib_flockfile_end (fp);
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return ret;
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}
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int
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fwide (FILE *fp,
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int mode)
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{
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return _fwide_r (_REENT, fp, mode);
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}
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