fgetwc (3p) - Linux Manuals

fgetwc: get a wide-character code from a stream

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 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 st_atime field of the file associated with stream for update. The st_atime field shall be marked for update by the first successful execution of fgetc(), fgets(), fgetwc(), fgetws(), fread(), fscanf(), getc(), getchar(), gets(), or scanf() using stream that returns data not supplied by a prior call to ungetc() or ungetwc().

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 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 process 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 process is ignoring or blocking the SIGTTIN signal or the process group 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.

COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 .