mirror of
git://sourceware.org/git/glibc.git
synced 2024-11-21 01:12:26 +08:00
115 lines
3.4 KiB
C
115 lines
3.4 KiB
C
/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public License as
|
|
published by the Free Software Foundation; either version 2 of the
|
|
License, or (at your option) any later version.
|
|
|
|
The GNU 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If
|
|
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
|
|
Cambridge, MA 02139, USA. */
|
|
|
|
/* This file provides glue between Unix stdio and GNU stdio.
|
|
It supports use of Unix stdio `getc' and `putc' (and, by extension,
|
|
`getchar' and `putchar') macros on GNU stdio streams (they are slow, but
|
|
they work). It also supports all stdio operations (including Unix
|
|
`getc' and `putc') on Unix's stdin, stdout, and stderr (the elements of
|
|
`_iob').
|
|
|
|
The reasoning behind this is to allow programs (and especially
|
|
libraries) compiled with Unix header files to work with the GNU C
|
|
library. */
|
|
|
|
#include <ansidecl.h>
|
|
#include <stdio.h>
|
|
#include <errno.h>
|
|
|
|
typedef union
|
|
{
|
|
struct
|
|
{
|
|
int magic;
|
|
FILE **streamp; /* Overlaps GNU stdio `bufp' member. */
|
|
/* These two overlap the GNU stdio `get_limit' and `put_limit'
|
|
members. They must be <= `streamp'/`bufp' for GNU getc and putc
|
|
to do the right thing. */
|
|
FILE **streamp2, **streamp3;
|
|
} glue;
|
|
struct _iobuf
|
|
{
|
|
int _cnt;
|
|
unsigned char *_ptr;
|
|
unsigned char *_base;
|
|
int _bufsiz;
|
|
short int _flag;
|
|
char _file;
|
|
} unix_iobuf;
|
|
FILE gnu_stream;
|
|
} unix_FILE;
|
|
|
|
/* These are the Unix stdio's stdin, stdout, and stderr.
|
|
In Unix stdin is (&_iob[0]), stdout is (&_iob[1]), and stderr is
|
|
(&_iob[2]). The magic number marks these as glued streams. The
|
|
__validfp macro in stdio.h is used by every stdio function. It checks
|
|
for glued streams, and replaces them with the GNU stdio stream. */
|
|
unix_FILE _iob[] =
|
|
{
|
|
#define S(name) { { _GLUEMAGIC, &name, &name, &name } }
|
|
S (stdin),
|
|
S (stdout),
|
|
S (stderr),
|
|
#undef S
|
|
};
|
|
|
|
/* Called by the Unix stdio `getc' macro.
|
|
The macro is assumed to look something like:
|
|
(--file->_cnt < 0 ? _filbuf (file) ...)
|
|
In a Unix stdio FILE `_cnt' is the first element.
|
|
In a GNU stdio or glued FILE, the first element is the magic number. */
|
|
int
|
|
DEFUN(_filbuf, (file), unix_FILE *file)
|
|
{
|
|
switch (++file->glue.magic) /* Compensate for Unix getc's decrement. */
|
|
{
|
|
case _GLUEMAGIC:
|
|
/* This is a glued stream. */
|
|
return getc (*file->glue.streamp);
|
|
|
|
case _IOMAGIC:
|
|
/* This is a normal GNU stdio stream. */
|
|
return getc ((FILE *) file);
|
|
|
|
default:
|
|
/* Bogus stream. */
|
|
errno = EINVAL;
|
|
return EOF;
|
|
}
|
|
}
|
|
|
|
/* Called by the Unix stdio `putc' macro. Much like getc, above. */
|
|
int
|
|
DEFUN(_flsbuf, (c, file),
|
|
int c AND unix_FILE *file)
|
|
{
|
|
/* Compensate for putc's decrement. */
|
|
switch (++file->glue.magic)
|
|
{
|
|
case _GLUEMAGIC:
|
|
return putc (c, *file->glue.streamp);
|
|
|
|
case _IOMAGIC:
|
|
return putc (c, (FILE *) file);
|
|
|
|
default:
|
|
errno = EINVAL;
|
|
return EOF;
|
|
}
|
|
}
|