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FGETWC(3P)                 POSIX Programmer's Manual                FGETWC(3P)
PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
NAME
       fgetwc -- get a wide-character code from a stream
SYNOPSIS
       #include <stdio.h>
       #include <wchar.h>
       wint_t fgetwc(FILE *stream);
DESCRIPTION
       The functionality described on this reference page is aligned with  the
       ISO C  standard.  Any  conflict between the requirements described here
       and the ISO C standard is unintentional. This  volume  of  POSIX.1-2008
       defers to the ISO C standard.
       The fgetwc() function shall obtain the next character (if present) from
       the input stream pointed to by stream, convert that to the  correspond-
       ing wide-character code, and advance the associated file position indi-
       cator for the stream (if defined).
       If an error occurs, the resulting value of the file position  indicator
       for the stream is unspecified.
       The  fgetwc()  function  may mark the last data access timestamp of the
       file associated with stream for update. The last data access  timestamp
       shall  be  marked  for  update  by  the  first  successful execution of
       fgetwc(), fgetws(), fwscanf(), getwc(),  getwchar(),  vfwscanf(),  vws-
       canf(),  or  wscanf()  using stream that returns data not supplied by a
       prior call to ungetwc().
       The fgetwc() function shall not change the setting of errno if success-
       ful.
RETURN VALUE
       Upon  successful  completion,  the  fgetwc()  function shall return the
       wide-character code of the character read from the input stream pointed
       to  by stream converted to a type wint_t.  If the end-of-file indicator
       for the stream is set, or if the stream is at end-of-file, the  end-of-
       file  indicator  for  the stream shall be set and fgetwc() shall return
       WEOF. If a read error occurs, the error indicator for the stream  shall
       be set, fgetwc() shall return WEOF, and shall set errno to indicate the
       error.  If an encoding error occurs, the error indicator for the stream
       shall  be set, fgetwc() shall return WEOF, and shall set errno to indi-
       cate the error.
ERRORS
       The fgetwc() function shall fail if data needs to be read and:
       EAGAIN The O_NONBLOCK flag is set for the  file  descriptor  underlying
              stream  and  the  thread would be delayed in the fgetwc() opera-
              tion.
       EBADF  The file descriptor  underlying  stream  is  not  a  valid  file
              descriptor open for reading.
       EILSEQ The  data  obtained  from the input stream does not form a valid
              character.
       EINTR  The read operation was terminated due to the receipt of  a  sig-
              nal, and no data was transferred.
       EIO    A  physical I/O error has occurred, or the process is in a back-
              ground process group attempting to  read  from  its  controlling
              terminal,  and  either the calling thread is blocking SIGTTIN or
              the process is ignoring SIGTTIN or  the  process  group  of  the
              process  is  orphaned.   This  error  may  also be generated for
              implementation-defined reasons.
       EOVERFLOW
              The file is a regular file and an attempt was made to read at or
              beyond  the  offset  maximum  associated  with the corresponding
              stream.
       The fgetwc() function may fail if:
       ENOMEM Insufficient storage space is available.
       ENXIO  A request was made of a nonexistent device, or the  request  was
              outside the capabilities of the device.
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       The ferror() or feof() functions must be used to distinguish between an
       error condition and an end-of-file condition.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       Section 2.5, Standard I/O Streams, feof(), ferror(), fopen()
       The Base Definitions volume of POSIX.1-2008, <stdio.h>, <wchar.h>
COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri-
       cal and Electronics Engineers,  Inc  and  The  Open  Group.   (This  is
       POSIX.1-2008  with  the  2013  Technical Corrigendum 1 applied.) In the
       event of any discrepancy between this version and the original IEEE and
       The  Open Group Standard, the original IEEE and The Open Group Standard
       is the referee document. The original Standard can be  obtained  online
       at http://www.unix.org/online.html .
       Any  typographical  or  formatting  errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files  to  man page format. To report such errors, see https://www.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                           FGETWC(3P)