FGETWC(P) POSIX Programmer's Manual FGETWC(P)
fgetwc - get a wide-character code from a stream
wint_t fgetwc(FILE *stream);
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
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
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.
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 read-
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
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 ignor-
ing or blocking the SIGTTIN signal or the process group is orphaned. This error may
also be generated for implementation-defined reasons.
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 capabil-
ities of the device.
The following sections are informative.
The ferror() or feof() functions must be used to distinguish between an error condition
and an end-of-file condition.
feof() , ferror() , fopen() , the Base Definitions volume of IEEE Std 1003.1-2001,
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 orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 FGETWC(P)