mirror of
https://gitlab.com/sortix/sortix.git
synced 2023-02-13 20:55:38 -05:00
66 lines
2.2 KiB
C++
66 lines
2.2 KiB
C++
/*******************************************************************************
|
|
|
|
Copyright(C) Jonas 'Sortie' Termansen 2013.
|
|
|
|
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/>.
|
|
|
|
fsetdefaultbuf.cpp
|
|
Sets up default buffering semantics for a FILE.
|
|
|
|
*******************************************************************************/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
|
|
extern "C" int fsetdefaultbuf(FILE* fp)
|
|
{
|
|
char* buf = (char*) malloc(sizeof(char) * BUFSIZ);
|
|
if ( !buf )
|
|
{
|
|
// TODO: Determine whether this is truly what we would want and whether
|
|
// a buffer should be pre-allocated when the FILE is created such that
|
|
// this situation _cannot_ occur.
|
|
|
|
// Alright, we're in a bit of a situation here. Normally, we'd go
|
|
// buffered but we are out of memory. We could either fail, but that
|
|
// would mean subsequent calls such as fgetc and fputc would also fail -
|
|
// however that we are out of memory doesn't mean that IO would also
|
|
// fail. Therefore we'll revert to unbuffered semantics and hope that's
|
|
// good enough.
|
|
|
|
return setvbuf(fp, NULL, _IONBF, 0);
|
|
}
|
|
|
|
// Determine the buffering semantics depending on whether the destination is
|
|
// an interactive device or not.
|
|
#ifdef SORTIX_KERNEL
|
|
int mode = _IOLBF; // TODO: Detect this?
|
|
#else
|
|
int mode = fp->buffer_mode != -1 ? fp->buffer_mode
|
|
: isatty(fileno(fp)) ? _IOLBF : _IOFBF;
|
|
#endif
|
|
int ret = setvbuf(fp, buf, mode, BUFSIZ);
|
|
if ( ret )
|
|
{
|
|
free(buf);
|
|
return -1;
|
|
}
|
|
|
|
// The buffer now belongs to the FILE.
|
|
fp->flags |= _FILE_BUFFER_OWNED;
|
|
return ret;
|
|
}
|