1FWIDE(3P) POSIX Programmer's Manual FWIDE(3P)
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6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
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13 fwide — set stream orientation
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16 #include <stdio.h>
17 #include <wchar.h>
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19 int fwide(FILE *stream, int mode);
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22 The functionality described on this reference page is aligned with the
23 ISO C standard. Any conflict between the requirements described here
24 and the ISO C standard is unintentional. This volume of POSIX.1‐2008
25 defers to the ISO C standard.
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27 The fwide() function shall determine the orientation of the stream
28 pointed to by stream. If mode is greater than zero, the function first
29 attempts to make the stream wide-oriented. If mode is less than zero,
30 the function first attempts to make the stream byte-oriented. Other‐
31 wise, mode is zero and the function does not alter the orientation of
32 the stream.
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34 If the orientation of the stream has already been determined, fwide()
35 shall not change it.
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37 The fwide() function shall not change the setting of errno if success‐
38 ful.
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40 Since no return value is reserved to indicate an error, an application
41 wishing to check for error situations should set errno to 0, then call
42 fwide(), then check errno, and if it is non-zero, assume an error has
43 occurred.
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46 The fwide() function shall return a value greater than zero if, after
47 the call, the stream has wide-orientation, a value less than zero if
48 the stream has byte-orientation, or zero if the stream has no orienta‐
49 tion.
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52 The fwide() function may fail if:
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54 EBADF The stream argument is not a valid stream.
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56 The following sections are informative.
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59 None.
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62 A call to fwide() with mode set to zero can be used to determine the
63 current orientation of a stream.
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66 None.
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69 None.
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72 The Base Definitions volume of POSIX.1‐2008, <stdio.h>, <wchar.h>
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75 Portions of this text are reprinted and reproduced in electronic form
76 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
77 -- Portable Operating System Interface (POSIX), The Open Group Base
78 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
79 cal and Electronics Engineers, Inc and The Open Group. (This is
80 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
81 event of any discrepancy between this version and the original IEEE and
82 The Open Group Standard, the original IEEE and The Open Group Standard
83 is the referee document. The original Standard can be obtained online
84 at http://www.unix.org/online.html .
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86 Any typographical or formatting errors that appear in this page are
87 most likely to have been introduced during the conversion of the source
88 files to man page format. To report such errors, see https://www.ker‐
89 nel.org/doc/man-pages/reporting_bugs.html .
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93IEEE/The Open Group 2013 FWIDE(3P)