New module 'freadahead'.

ChangeLog

@@ -1,3 +1,11 @@
+2007-08-19  Bruno Haible  <bruno@clisp.org>
+
+	* modules/freadahead: New file.
+	* lib/freadahead.h: New file.
+	* lib/freadahead.c: New file.
+	* MODULES.html.sh (File stream based Input/Output): Add freadahead,
+	fbufmode, fpurge, freadable, fwritable.
+
 2007-08-19  Eric Blake  <ebb9@byu.net>
 
 	Test yesno in combination with closein.

MODULES.html.sh

@@ -2194,9 +2194,14 @@ func_all_modules ()
   func_module close-stream
   func_module closein
   func_module closeout
+  func_module fbufmode
   func_module fopen-safer
   func_module fpending
+  func_module fpurge
+  func_module freadable
+  func_module freadahead
   func_module freading
+  func_module fwritable
   func_module fwriting
   func_module getpass
   func_module getpass-gnu

lib/freadahead.c

@@ -0,0 +1,62 @@
+/* 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 "freadahead.h"
+
+size_t
+freadahead (FILE *fp)
+{
+#if defined _IO_ferror_unlocked     /* GNU libc, BeOS */
+  if (fp->_IO_write_ptr > fp->_IO_write_base)
+    return 0;
+  return fp->_IO_read_end - fp->_IO_read_ptr;
+#elif defined __sferror             /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */
+  if ((fp->_flags & __SWR) != 0 || fp->_r < 0)
+    return 0;
+  return fp->_r;
+#elif defined _IOERR                /* AIX, HP-UX, IRIX, OSF/1, Solaris, mingw */
+# if defined __sun && defined _LP64 /* Solaris/{SPARC,AMD64} 64-bit */
+#  define fp_ ((struct { unsigned char *_ptr; \
+			 unsigned char *_base; \
+			 unsigned char *_end; \
+			 long _cnt; \
+			 int _file; \
+			 unsigned int _flag; \
+		       } *) fp)
+  if ((fp_->_flag & _IOWRT) != 0)
+    return 0;
+  return fp_->_cnt;
+# else
+  if ((fp->_flag & _IOWRT) != 0)
+    return 0;
+  return fp->_cnt;
+# endif
+#elif defined __UCLIBC__            /* uClibc */
+# ifdef __STDIO_BUFFERS
+  if (fp->__modeflags & __FLAG_WRITING)
+    return 0;
+  return fp->__bufread - fp->__bufpos;
+# else
+  return 0;
+# endif
+#else
+ #error "Please port gnulib freadahead.c to your platform! Look at the definition of fflush, fread on your system, then report this to bug-gnulib."
+#endif
+}

lib/freadahead.h

@@ -0,0 +1,37 @@
+/* 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 <stddef.h>
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Assuming the stream STREAM is open for reading:
+   Return the number of bytes waiting in the input buffer of STREAM.
+
+   If this number is 0 and the stream is not currently writing,
+   fflush (STREAM) is known to be a no-op.
+
+   STREAM must not be wide-character oriented.  */
+
+extern size_t freadahead (FILE *stream);
+
+#ifdef __cplusplus
+}
+#endif

modules/freadahead

@@ -0,0 +1,24 @@
+Description:
+freadahead() function: Determine the number of bytes waiting in the input
+buffer of a stream.
+
+Files:
+lib/freadahead.h
+lib/freadahead.c
+
+Depends-on:
+
+configure.ac:
+
+Makefile.am:
+lib_SOURCES += freadahead.c
+
+Include:
+"freadahead.h"
+
+License:
+LGPL
+
+Maintainer:
+Bruno Haible
+