From: Bruno Haible <bruno@clisp.org>
Date: Sat, 14 Apr 2007 00:14:56 +0000 (+0000)
Subject: New module 'fwritable'.
X-Git-Tag: cvs-readonly~529
X-Git-Url: http://erislabs.org.uk/gitweb/?a=commitdiff_plain;h=d1b26967b8d0882441359644bd9122345bd2b03a;p=gnulib.git

New module 'fwritable'.
---

diff --git a/ChangeLog b/ChangeLog
index 206c16518..beaa2fa5f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2007-04-13  Bruno Haible  <bruno@clisp.org>
 
+	* modules/fwritable: New file.
+	* lib/fwritable.h: New file.
+	* lib/fwritable.c: New file.
+	* m4/fwritable.m4: New file.
+
+2007-04-13  Bruno Haible  <bruno@clisp.org>
+
 	* modules/freadable-tests: New file.
 	* tests/test-freadable.c: New file.
 
diff --git a/lib/fwritable.c b/lib/fwritable.c
new file mode 100644
index 000000000..2885deabe
--- /dev/null
+++ b/lib/fwritable.c
@@ -0,0 +1,38 @@
+/* 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 "fwritable.h"
+
+bool
+fwritable (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_WRITES) == 0;
+#elif defined __sferror             /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */
+  return (fp->_flags & (__SRW | __SWR)) != 0;
+#elif defined _IOERR                /* AIX, HP-UX, IRIX, OSF/1, Solaris, mingw */
+  return (fp->_flag & (_IORW | _IOWRT)) != 0;
+#else
+ #error "Please port gnulib fwritable.c to your platform!"
+#endif
+}
diff --git a/lib/fwritable.h b/lib/fwritable.h
new file mode 100644
index 000000000..94dcc77e6
--- /dev/null
+++ b/lib/fwritable.h
@@ -0,0 +1,43 @@
+/* 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 writing, false if it supports
+   only reading.
+   STREAM must not be wide-character oriented.
+   The result doesn't change until the stream is closed or re-opened.  */
+
+#if HAVE___FWRITABLE /* glibc >= 2.2, Solaris >= 7 */
+
+# include <stdio_ext.h>
+# define fwritable(stream) (__fwritable (stream) != 0)
+
+#else
+
+# ifdef __cplusplus
+extern "C" {
+# endif
+
+extern bool fwritable (FILE *stream);
+
+# ifdef __cplusplus
+}
+# endif
+
+#endif
diff --git a/m4/fwritable.m4 b/m4/fwritable.m4
new file mode 100644
index 000000000..057d16a5d
--- /dev/null
+++ b/m4/fwritable.m4
@@ -0,0 +1,13 @@
+# fwritable.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_FWRITABLE],
+[
+  AC_CHECK_FUNCS_ONCE([__fwritable])
+  if test $ac_cv_func___fwritable = no; then
+    AC_LIBOBJ([fwritable])
+  fi
+])
diff --git a/modules/fwritable b/modules/fwritable
new file mode 100644
index 000000000..43bd66ba1
--- /dev/null
+++ b/modules/fwritable
@@ -0,0 +1,25 @@
+Description:
+fwritable() function: Determine whether a FILE stream supports writing.
+
+Files:
+lib/fwritable.h
+lib/fwritable.c
+m4/fwritable.m4
+
+Depends-on:
+stdbool
+
+configure.ac:
+gl_FUNC_FWRITABLE
+
+Makefile.am:
+
+Include:
+"fwritable.h"
+
+License:
+LGPL
+
+Maintainer:
+Bruno Haible, Eric Blake
+