FGETWC(P) POSIX Programmer's Manual FGETWC(P)NAMEfgetwc - 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 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 st_atime field of the file associ‐
ated 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() 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 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.
SEE ALSOfeof() , ferror() , fopen() , the Base Definitions volume of
IEEE Std 1003.1-2001, <stdio.h>, <wchar.h>
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 .
IEEE/The Open Group 2003 FGETWC(P)
