This generalizes the '__freadable' solarism.
2007-04-13 Bruno Haible <[EMAIL PROTECTED]>
* modules/freadable: New file.
* lib/freadable.h: New file.
* lib/freadable.c: New file.
* m4/freadable.m4: New file.
============================ modules/freadable ================================
Description:
freadable() function: Determine whether a FILE stream supports reading.
Files:
lib/freadable.h
lib/freadable.c
m4/freadable.m4
Depends-on:
stdbool
configure.ac:
gl_FUNC_FREADABLE
Makefile.am:
Include:
"freadable.h"
License:
LGPL
Maintainer:
Bruno Haible, Eric Blake
============================= lib/freadable.h =================================
/* Retrieve information about a FILE stream.
Copyright (C) 2007 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
#include <stdbool.h>
#include <stdio.h>
/* Return true if the stream STREAM supports reading, false if it supports
only writing, i.e. if it was opened write-only or append-only.
STREAM must not be wide-character oriented.
The result doesn't change until the stream is closed or re-opened. */
#if HAVE___FREADABLE /* glibc >= 2.2, Solaris >= 7 */
# include <stdio_ext.h>
# define freadable(stream) (__freadable (stream) != 0)
#else
# ifdef __cplusplus
extern "C" {
# endif
extern bool freadable (FILE *stream);
# ifdef __cplusplus
}
# endif
#endif
============================= lib/freadable.c =================================
/* Retrieve information about a FILE stream.
Copyright (C) 2007 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
#include <config.h>
/* Specification. */
#include "freadable.h"
bool
freadable (FILE *fp)
{
/* Most systems provide FILE as a struct and the necessary bitmask in
<stdio.h>, because they need it for implementing getc() and putc() as
fast macros. */
#if defined _IO_ferror_unlocked /* GNU libc, BeOS */
return (fp->_flags & _IO_NO_READS) == 0;
#elif defined __sferror /* FreeBSD, NetBSD, OpenBSD, MacOS X,
Cygwin */
return (fp->_flags & (__SRW | __SRD)) != 0;
#elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, mingw
*/
return (fp->_flag & (_IORW | _IOREAD)) != 0;
#else
#error "Please port gnulib freadable.c to your platform!"
#endif
}
============================= m4/freadable.m4 =================================
# freadable.m4 serial 1
dnl Copyright (C) 2007 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_FUNC_FREADABLE],
[
AC_CHECK_FUNCS_ONCE([__freadable])
if test $ac_cv_func___freadable = no; then
AC_LIBOBJ([freadable])
fi
])
