Add support for dup2'ing files. Infrastructure and ROMFS done. Still need FAT, BINFS, NXFFS, and NFS

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5516 42af7a65-404d-4744-a932-0658087f49c3

ChangeLog.txt

@@ -466,3 +466,4 @@
 	  death-of-child signals (SIGCHLD).
 	* apps/examples/ostest/waitpid.c:  Add a test for waitpid(), waitid(),
 	  and wait().
+	* builtin/binfs.c:  Add hooks for dup() method (not implemented).

builtin/binfs.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * apps/builtin/binfs.c
  *
- *   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2011-2013 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -118,7 +118,9 @@ const struct mountpt_operations binfs_operations =
   NULL,              /* write */
   NULL,              /* seek */
   binfs_ioctl,       /* ioctl */
+
   NULL,              /* sync */
+  NULL,              /* dup */
 
   binfs_opendir,     /* opendir */
   NULL,              /* closedir */

examples/posix_spawn/spawn_main.c

@@ -89,15 +89,6 @@
 #  error "You must not disable loadable modules via CONFIG_BINFMT_DISABLE in your configuration file"
 #endif
 
-/* The redirection test does not work.  This is because it tries to redirect
- * file as stdin.  That won't work now because (1) the file descriptors must
- * be dup'ed when the new task is created, and (2) there is no support in
- * place for dup'ing file descriptors for anything other than sockets and
- * character drivers.  This is a bug!
- */
-
-#define FILE_DUP_BUG 1
-
 /* Describe the ROMFS file system */
 
 #define SECTORSIZE   512
@@ -147,9 +138,7 @@ static unsigned int g_mmstep;     /* Memory Usage at beginning of test step */
 
 static const char delimiter[] =
   "****************************************************************************";
-#ifndef FILE_DUP_BUG
 static const char g_redirect[] = "redirect";
-#endif
 static const char g_hello[]    = "hello";
 static const char g_data[]     = "testdata.txt";
 
@@ -375,8 +364,6 @@ int spawn_main(int argc, char *argv[])
    * Case 2: Simple program with redirection of stdin to a file input
    *************************************************************************/
 
-#ifndef FILE_DUP_BUG
-
   /* Output a seperated so that we can clearly discriminate the output of
    * this program from the others.
    */
@@ -463,7 +450,6 @@ int spawn_main(int argc, char *argv[])
   posix_spawnattr_dump(&attr);
 
   mm_update(&g_mmstep, "after file_action/attr destruction");
-#endif
 
   /* Clean-up */