fgetwc(3p) — Linux manual page

PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

FGETWC(3P)              POSIX Programmer's Manual              FGETWC(3P)

PROLOG         top

       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         top

       fgetwc — get a wide-character code from a stream

SYNOPSIS         top

       #include <stdio.h>
       #include <wchar.h>

       wint_t fgetwc(FILE *stream);

DESCRIPTION         top

       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         top

       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         top

       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         top

       None.

APPLICATION USAGE         top

       The ferror() or feof() functions must be used to distinguish
       between an error condition and an end-of-file condition.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       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         top

       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)