70 lines
2.0 KiB
C++
70 lines
2.0 KiB
C++
/*******************************************************************************
|
|
|
|
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012.
|
|
|
|
This file is part of the Sortix C Library.
|
|
|
|
The Sortix C Library is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU Lesser General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or (at your
|
|
option) any later version.
|
|
|
|
The Sortix C Library is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
|
|
License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
fgetc.cpp
|
|
Reads a single character from a FILE.
|
|
|
|
*******************************************************************************/
|
|
|
|
#include <assert.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
|
|
#include <errno.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
extern "C" int fgetc(FILE* fp)
|
|
{
|
|
if ( fp->flags & _FILE_NO_BUFFER )
|
|
{
|
|
unsigned char c;
|
|
if ( fread(&c, sizeof(c), 1, fp) != 1 )
|
|
return EOF;
|
|
return c;
|
|
}
|
|
|
|
if ( !fp->read_func )
|
|
return EOF; // TODO: ferror doesn't report error!
|
|
|
|
if ( fp->flags & _FILE_LAST_WRITE )
|
|
fflush_stop_writing(fp);
|
|
fp->flags |= _FILE_LAST_READ;
|
|
|
|
if ( fp->offset_input_buffer < fp->amount_input_buffered )
|
|
retry:
|
|
return fp->buffer[fp->offset_input_buffer++];
|
|
|
|
assert(fp->buffer && fp->buffersize);
|
|
|
|
size_t pushback = _FILE_MAX_PUSHBACK;
|
|
if ( fp->buffersize <= pushback )
|
|
pushback = 0;
|
|
size_t count = fp->buffersize - pushback;
|
|
size_t size = sizeof(unsigned char);
|
|
size_t numread = fp->read_func(fp->buffer + pushback, size, count, fp->user);
|
|
if ( !numread )
|
|
return EOF;
|
|
|
|
fp->offset_input_buffer = pushback;
|
|
fp->amount_input_buffered = pushback + numread;
|
|
|
|
goto retry;
|
|
}
|