fgetc#
Synopsis#
#include <stdio.h>
int fgetc(FILE *stream);
Status#
Partially implemented
Conformance#
IEEE Std 1003.1-2017
Description#
If the end-of-file indicator for the input stream pointed to by stream is not set and a next byte is present, the
fgetc()
function shall obtain the next byte as an unsigned char converted to an int, from the input stream pointed
to by stream, and advance the associated file position indicator for the stream (if defined). Since fgetc()
operates on bytes, reading a character consisting of multiple bytes (or “a multibyte character”) may require multiple
calls to fgetc()
.
The fgetc()
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 fgetc()
, fgets()
,
fread()
, fscanf()
, getc()
, getchar()
, getdelim()
, getline()
, gets()
, or scanf()
using stream that
returns data not supplied by a prior call to ungetc()
.
Return value#
Upon successful completion, fgetc()
shall return the next byte from the input stream pointed to by stream.
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 fgetc()
shall return EOF
. If a read error occurs, the error indicator for the
stream shall be set, fgetc()
shall return EOF
and shall set errno
to indicate the error.
Errors#
The fgetc()
function shall fail if data needs to be read and:
EAGAIN
- TheO_NONBLOCK
flag is set for the file descriptor underlying stream and the thread would be delayed in thefgetc()
operation.EBADF
- The file descriptor underlying stream is not a valid file descriptor open for reading.EINTR
- The read operation was terminated due to the receipt of a signal, and no data was transferred.EIO
- A physicalI/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 blockingSIGTTIN
or the process is ignoringSIGTTIN
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 fgetc()
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.
Tests#
Untested
Known bugs#
None