1FGETWC(P) POSIX Programmer's Manual FGETWC(P)
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6 fgetwc - get a wide-character code from a stream
7
9 #include <stdio.h>
10 #include <wchar.h>
11 wint_t fgetwc(FILE *stream);
13
16 The fgetwc() function shall obtain the next character (if present) from
17 the input stream pointed to by stream, convert that to the correspond‐
18 ing wide-character code, and advance the associated file position indi‐
19 cator for the stream (if defined).
20 If an error occurs, the resulting value of the file position indicator
22 for the stream is unspecified.
23 The fgetwc() function may mark the st_atime field of the file associ‐
25 ated with stream for update. The st_atime field shall be marked for
26 update by the first successful execution of fgetc(), fgets(), fgetwc(),
27 fgetws(), fread(), fscanf(), getc(), getchar(), gets(), or scanf()
28 using stream that returns data not supplied by a prior call to ungetc()
29 or ungetwc().
30
32 Upon successful completion, the fgetwc() function shall return the
33 wide-character code of the character read from the input stream pointed
34 to by stream converted to a type wint_t. If the stream is at end-of-
35 file, the end-of-file indicator for the stream shall be set and
36 fgetwc() shall return WEOF. If a read error occurs, the error indicator
37 for the stream shall be set, fgetwc() shall return WEOF, and shall
38 set errno to indicate the error. If an encoding error occurs, the
39 error indicator for the stream shall be set, fgetwc() shall return
40 WEOF, and shall set errno to indicate the error.
41
43 The fgetwc() function shall fail if data needs to be read and:
44 EAGAIN The O_NONBLOCK flag is set for the file descriptor underlying
46 stream and the process would be delayed in the fgetwc() opera‐
47 tion.
48 EBADF The file descriptor underlying stream is not a valid file
50 descriptor open for reading.
51 EILSEQ The data obtained from the input stream does not form a valid
53 character.
54 EINTR The read operation was terminated due to the receipt of a sig‐
56 nal, and no data was transferred.
57 EIO A physical I/O error has occurred, or the process is in a back‐
59 ground process group attempting to read from its controlling
60 terminal, and either the process is ignoring or blocking the
61 SIGTTIN signal or the process group is orphaned. This error may
62 also be generated for implementation-defined reasons.
63 EOVERFLOW
65 The file is a regular file and an attempt was made to read at or
66 beyond the offset maximum associated with the corresponding
67 stream.
68 The fgetwc() function may fail if:
71 ENOMEM Insufficient storage space is available.
73 ENXIO A request was made of a nonexistent device, or the request was
75 outside the capabilities of the device.
76 The following sections are informative.
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81 None.
82
84 The ferror() or feof() functions must be used to distinguish between an
85 error condition and an end-of-file condition.
86
88 None.
89
91 None.
92
94 feof() , ferror() , fopen() , the Base Definitions volume of
95 IEEE Std 1003.1-2001, <stdio.h>, <wchar.h>
96
98 Portions of this text are reprinted and reproduced in electronic form
99 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
100 -- Portable Operating System Interface (POSIX), The Open Group Base
101 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
102 Electrical and Electronics Engineers, Inc and The Open Group. In the
103 event of any discrepancy between this version and the original IEEE and
104 The Open Group Standard, the original IEEE and The Open Group Standard
105 is the referee document. The original Standard can be obtained online
106 at http://www.opengroup.org/unix/online.html .
107IEEE/The Open Group 2003 FGETWC(P)