fgetwc(3p) — Linux manual page

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.1‐2017 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.

SEE ALSO

       Section 2.5, Standard I/O Streams, feof(3p), ferror(3p),
       fopen(3p)

       The Base Definitions volume of POSIX.1‐2017, stdio.h(0p),
       wchar.h(0p)

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  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.opengroup.org/unix/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.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group               2017                        FGETWC(3P)

Pages that refer to this page: wchar.h(0p), fgetws(3p), fscanf(3p), fwscanf(3p), getwc(3p), getwchar(3p)

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