# fgetwc

## 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.1‐2017 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
           corresponding wide-character code, and advance the associated file
           position indicator 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_(), _vwscanf_(), 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
           successful.
    


## 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 indicate 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_() operation.
    
           **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
                  signal, and no data was transferred.
    
           **EIO** A physical I/O error has occurred, or the process is in a
                  background 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.
    


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