Integrate perlio:

[  7539]
PerlIO infrastructure complete.

[  7538]
Type tweaks + less contorted allocation scheme

[  7537]
Fix for stdio as default "discipline" - PerlIO_init() was fdopen(2,"w")'ing
a fresh FILE * rather than re-using stderr. Which meant PerlIO_stderr() was
fully buffered rather than unbuffered (on Solaris, Linux seemed to do something
sensible) which lead to some interesting fails.

[  7535]
Implement stack of layers - (perlio.c _is_ derived from the old file honest...)
- Works on Linux with
perlio + unix
stdio
- Works on Solaris with
perlio + unix
- Fails ONE test (print to STDIN should fail) on Solaris with stdio.
- Fails (hangs in openpid) if you try and stack
perlio + stdio - Linux stdio's read() logic is hanging.

[  7492]
Change files which are mysteriously different to mainline to be
copies of mainline.

[  7491]
Perlio fixes discovered on big-endian & very traditional Solaris:
- typo in endian code in putc.
- Don't allow read of write-only files and vice-versa
- and off-by-one in flush-all loop.
Remove debug calls as they were using GCC specific features.

[  7484]
PerlIO passes all tests.

[  7482]
Include <unistd.h> to get correct lseek() prototype etc.
(I thought perl.h did that) - down to two fails
- comp/require.t (last test)
- lib/io_xs.t - possibly import/export of FILE * ?

[  7480]
Fixed two bugs:
- error code not being set on close (of broken pipe)
- append mode was truncating.
At least one seek/tell bug remains.

[  7479]
Prototype (stdio-like) PerlIO passing basic tests. Checked in
in case of accidents. Still several worrying fails, no line disciplines yet.

p4raw-link: @7539 on //depot/perlio: f3862f8bcf6d3aa824432654b287f4ebd64db17f
p4raw-link: @7538 on //depot/perlio: 05d1247b4b0324742a6edccf90ff347d8905fcdb
p4raw-link: @7537 on //depot/perlio: c7fc522f3f7e35723803aaacf8c326dac22dae76
p4raw-link: @7535 on //depot/perlio: 9e353e3b7330a59ca210e75e4484e7762fcd1ce4
p4raw-link: @7492 on //depot/perlio: e9e021e644582e6ca1e9f6b4c1f1a8a7c7e2a58d
p4raw-link: @7491 on //depot/perlio: f89522bf4daaf3c639b016283ffbace973e9c323
p4raw-link: @7484 on //depot/perlio: b1ef6e3bd726972447a8b536231f096656903bb3
p4raw-link: @7482 on //depot/perlio: 02f66e2f9235025f08502389e56df70aa71733c0
p4raw-link: @7480 on //depot/perlio: bb9950b796df42e2f824a072ae878c87e977be20
p4raw-link: @7479 on //depot/perlio: 6f9d8c32c6a78a47c6088f50d7051d779f712ee1

p4raw-id: //depot/perl@7547

8 files changed, 1769 insertions, 282 deletions

diff --git a/MANIFEST b/MANIFEST
index 1b4021353d..2b47007729 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -772,6 +772,7 @@ lib/open2.pl		Open a two-ended pipe (uses IPC::Open2)
 lib/open3.pl		Open a three-ended pipe (uses IPC::Open3)
 lib/overload.pm		Module for overloading perl operators
 lib/perl5db.pl		Perl debugging routines
+lib/perlio.pm		Perl IO interface pragma
 lib/pwd.pl		Routines to keep track of PWD environment variable
 lib/shellwords.pl	Perl library to split into words with shell quoting
 lib/sigtrap.pm		For trapping an abort and giving traceback
diff --git a/iperlsys.h b/iperlsys.h
index 6844801bb4..55471cdbd4 100644
--- a/iperlsys.h
+++ b/iperlsys.h
@@ -78,11 +78,17 @@ extern void PerlIO_init (void);
 typedef Signal_t (*Sighandler_t) (int);
 #endif
 
+#ifndef Fpos_t
+#define Fpos_t Off_t
+#endif
+
 #if defined(PERL_IMPLICIT_SYS)
 
 #ifndef PerlIO
-typedef struct _PerlIO PerlIO;
-#endif
+typedef struct _PerlIO PerlIOl;
+typedef PerlIOl *PerlIO;
+#define PerlIO PerlIO
+#endif /* No PerlIO */
 
 /* IPerlStdIO		*/
 struct IPerlStdIO;
@@ -120,7 +126,7 @@ typedef void		(*LPSetCnt)(struct IPerlStdIO*, PerlIO*, int);
 typedef void		(*LPSetPtrCnt)(struct IPerlStdIO*, PerlIO*, char*,
 			    int);
 typedef void		(*LPSetlinebuf)(struct IPerlStdIO*, PerlIO*);
-typedef int		(*LPPrintf)(struct IPerlStdIO*, PerlIO*, const char*, 
+typedef int		(*LPPrintf)(struct IPerlStdIO*, PerlIO*, const char*,
 			    ...);
 typedef int		(*LPVprintf)(struct IPerlStdIO*, PerlIO*, const char*,
 			    va_list);
@@ -134,6 +140,7 @@ typedef int		(*LPSetpos)(struct IPerlStdIO*, PerlIO*,
 typedef void		(*LPInit)(struct IPerlStdIO*);
 typedef void		(*LPInitOSExtras)(struct IPerlStdIO*);
 typedef PerlIO*		(*LPFdupopen)(struct IPerlStdIO*, PerlIO*);
+typedef int		(*LPIsUtf8)(struct IPerlStdIO*, PerlIO*);
 
 struct IPerlStdIO
 {
@@ -176,6 +183,7 @@ struct IPerlStdIO
     LPInit		pInit;
     LPInitOSExtras	pInitOSExtras;
     LPFdupopen		pFdupopen;
+    LPIsUtf8		pIsUtf8;
 };
 
 struct IPerlStdIOInfo
@@ -185,19 +193,19 @@ struct IPerlStdIOInfo
 };
 
 #ifdef USE_STDIO_PTR
-#  define PerlIO_has_cntptr(f)		1       
+#  define PerlIO_has_cntptr(f)		1
 #  ifdef STDIO_PTR_LVALUE
 #    ifdef  STDIO_CNT_LVALUE
-#      define PerlIO_canset_cnt(f)	1      
+#      define PerlIO_canset_cnt(f)	1
 #      ifdef STDIO_PTR_LVAL_NOCHANGE_CNT
-#        define PerlIO_fast_gets(f)	1        
+#        define PerlIO_fast_gets(f)	1
 #      endif
 #    else /* STDIO_CNT_LVALUE */
-#      define PerlIO_canset_cnt(f)	0      
+#      define PerlIO_canset_cnt(f)	0
 #    endif
 #  else /* STDIO_PTR_LVALUE */
 #    ifdef STDIO_PTR_LVAL_SETS_CNT
-#      define PerlIO_fast_gets(f)	1        
+#      define PerlIO_fast_gets(f)	1
 #    endif
 #  endif
 #else  /* USE_STDIO_PTR */
@@ -206,7 +214,7 @@ struct IPerlStdIOInfo
 #endif /* USE_STDIO_PTR */
 
 #ifndef PerlIO_fast_gets
-#define PerlIO_fast_gets(f)		0        
+#define PerlIO_fast_gets(f)		0
 #endif
 
 #ifdef FILE_base
@@ -274,7 +282,7 @@ struct IPerlStdIOInfo
 #define PerlIO_printf		Perl_fprintf_nocontext
 #define PerlIO_stdoutf		*PL_StdIO->pPrintf
 #define PerlIO_vprintf(f,fmt,a)						\
-	(*PL_StdIO->pVprintf)(PL_StdIO, (f),(fmt),a)          
+	(*PL_StdIO->pVprintf)(PL_StdIO, (f),(fmt),a)
 #define PerlIO_tell(f)							\
 	(*PL_StdIO->pTell)(PL_StdIO, (f))
 #define PerlIO_seek(f,o,w)						\
@@ -294,18 +302,22 @@ struct IPerlStdIOInfo
 	(*PL_StdIO->pInitOSExtras)(PL_StdIO)
 #define PerlIO_fdupopen(f)						\
 	(*PL_StdIO->pFdupopen)(PL_StdIO, (f))
+#define PerlIO_isutf8(f)						\
+	(*PL_StdIO->pIsUtf8)(PL_StdIO, (f))
 
 #else	/* PERL_IMPLICIT_SYS */
 
 #include "perlsdio.h"
 #include "perl.h"
 #define PerlIO_fdupopen(f)		(f)
+#define PerlIO_isutf8(f)		0
 
 #endif	/* PERL_IMPLICIT_SYS */
 
 #ifndef PERLIO_IS_STDIO
 #ifdef USE_SFIO
 #include "perlsfio.h"
+#define PerlIO_isutf8(f)		0
 #endif /* USE_SFIO */
 #endif /* PERLIO_IS_STDIO */
 
@@ -331,14 +343,11 @@ struct IPerlStdIOInfo
 #endif
 
 #ifndef PerlIO
-struct _PerlIO;
-#define PerlIO struct _PerlIO
+typedef struct _PerlIO PerlIOl;
+typedef PerlIOl *PerlIO;
+#define PerlIO PerlIO
 #endif /* No PerlIO */
 
-#ifndef Fpos_t
-#define Fpos_t long
-#endif
-
 #ifndef NEXT30_NO_ATTRIBUTE
 #ifndef HASATTRIBUTE       /* disable GNU-cc attribute checking? */
 #ifdef  __attribute__      /* Avoid possible redefinition errors */
@@ -480,7 +489,9 @@ extern int	PerlIO_setpos		(PerlIO *,const Fpos_t *);
 #ifndef PerlIO_fdupopen
 extern PerlIO *	PerlIO_fdupopen		(PerlIO *);
 #endif
-
+#ifndef PerlIO_isutf8
+extern int	PerlIO_isutf8		(PerlIO *);
+#endif
 
 /*
  *   Interface for directory functions
@@ -558,7 +569,7 @@ struct IPerlDirInfo
 #define PerlDir_mkdir(name, mode)	Mkdir((name), (mode))
 #ifdef VMS
 #  define PerlDir_chdir(n)		Chdir(((n) && *(n)) ? (n) : "SYS$LOGIN")
-#else 
+#else
 #  define PerlDir_chdir(name)		chdir((name))
 #endif
 #define PerlDir_rmdir(name)		rmdir((name))
@@ -1262,7 +1273,7 @@ typedef int		(*LPRecvfrom)(struct IPerlSock*, SOCKET, char*, int,
 typedef int		(*LPSelect)(struct IPerlSock*, int, char*, char*,
 			    char*, const struct timeval*);
 typedef int		(*LPSend)(struct IPerlSock*, SOCKET, const char*, int,
-			    int); 
+			    int);
 typedef int		(*LPSendto)(struct IPerlSock*, SOCKET, const char*,
 			    int, int, const struct sockaddr*, int);
 typedef void		(*LPSethostent)(struct IPerlSock*, int);
diff --git a/lib/perlio.pm b/lib/perlio.pm
new file mode 100644
index 0000000000..48acfbbf0b
--- /dev/null
+++ b/lib/perlio.pm
@@ -0,0 +1,87 @@
+package perlio;
+1;
+__END__
+
+=head1 NAME
+
+perlio - perl pragma to configure C level IO
+
+=head1 SYNOPSIS
+
+  Shell:
+    PERLIO=perlio perl ....
+
+    print "Have ",join(',',keys %perlio::layers),"\n";
+    print "Using ",join(',',@perlio::layers),"\n";
+
+
+=head1 DESCRIPTION
+
+Mainly a Place holder for now.
+
+The C<%perlio::layers> hash is a record of the available "layers" that may be pushed
+onto a C<PerlIO> stream.
+
+The C<@perlio::layers> array is the current set of layers that are used when
+a new C<PerlIO> stream is opened. The C code looks are the array each time
+a stream is opened so the "stack" can be manipulated by messing with the array :
+
+    pop(@perlio::layers);
+    push(@perlio::layers,$perlio::layers{'stdio'});
+
+The values if both the hash and the array are perl objects, of class C<perlio::Layer>
+which are created by the C code in C<perlio.c>. As yet there is nothing useful you
+can do with the objects at the perl level.
+
+There are three layers currently defined:
+
+=over 4
+
+=item unix
+
+Low level layer which calls C<read>, C<write> and C<lseek> etc.
+
+=item stdio
+
+Layer which calls C<fread>, C<fwrite> and C<fseek>/C<ftell> etc.
+Note that as this is "real" stdio it will ignore any layers beneath it and
+got straight to the operating system via the C library as usual.
+
+=item perlio
+
+This is a re-implementation of "stdio-like" buffering written as a PerlIO "layer".
+As such it will call whatever layer is below it for its operations.
+
+=back
+
+=head2 Defaults and how to override them
+
+If C<Configure> found out how to do "fast" IO using system's stdio, then
+the default layers are :
+
+  unix stdio
+
+Otherwise the default layers are
+
+  unix perlio
+
+(STDERR will have just unix in this case as that is optimal way to make it
+"unbuffered" - do not add a buffering layer!)
+
+The default may change once perlio has been better tested and tuned.
+
+The default can be overridden by setting the environment variable PERLIO
+to a space separated list of layers (unix is always pushed first).
+This can be used to see the effect of/bugs in the various layers e.g.
+
+  cd .../perl/t
+  PERLIO=stdio  ./perl harness
+  PERLIO=perlio ./perl harness
+
+=head1 AUTHOR
+
+Nick Ing-Simmons E<lt>nick@ing-simmons.netE<gt>
+
+=cut
+
+
diff --git a/objXSUB.h b/objXSUB.h
index 4d5ff6b8a5..5827b7225c 100644
--- a/objXSUB.h
+++ b/objXSUB.h
@@ -1901,7 +1901,7 @@
 #define Perl_whichsig		pPerl->Perl_whichsig
 #undef  whichsig
 #define whichsig		Perl_whichsig
-#if defined(USE_PURE_BISON)
+#ifdef USE_PURE_BISON
 #else
 #endif
 #if defined(MYMALLOC)
diff --git a/perlapi.c b/perlapi.c
index efa716410c..a9dd2f070d 100644
--- a/perlapi.c
+++ b/perlapi.c
@@ -2237,21 +2237,21 @@ Perl_init_i18nl14n(pTHXo_ int printwarn)
 
 #undef  Perl_new_collate
 void
-Perl_new_collate(pTHXo_ const char* newcoll)
+Perl_new_collate(pTHXo_ char* newcoll)
 {
     ((CPerlObj*)pPerl)->Perl_new_collate(newcoll);
 }
 
 #undef  Perl_new_ctype
 void
-Perl_new_ctype(pTHXo_ const char* newctype)
+Perl_new_ctype(pTHXo_ char* newctype)
 {
     ((CPerlObj*)pPerl)->Perl_new_ctype(newctype);
 }
 
 #undef  Perl_new_numeric
 void
-Perl_new_numeric(pTHXo_ const char* newcoll)
+Perl_new_numeric(pTHXo_ char* newcoll)
 {
     ((CPerlObj*)pPerl)->Perl_new_numeric(newcoll);
 }
@@ -3439,7 +3439,7 @@ Perl_whichsig(pTHXo_ char* sig)
 {
     return ((CPerlObj*)pPerl)->Perl_whichsig(sig);
 }
-#if defined(USE_PURE_BISON)
+#ifdef USE_PURE_BISON
 #else
 #endif
 #if defined(MYMALLOC)
diff --git a/perlio.c b/perlio.c
index 969b8d1c6d..5d8ecdbb95 100644
--- a/perlio.c
+++ b/perlio.c
@@ -7,7 +7,6 @@
  *
  */
 
-
 #define VOIDUSED 1
 #ifdef PERL_MICRO
 #   include "uconfig.h"
@@ -15,14 +14,14 @@
 #   include "config.h"
 #endif
 
-#define PERLIO_NOT_STDIO 0 
+#define PERLIO_NOT_STDIO 0
 #if !defined(PERLIO_IS_STDIO) && !defined(USE_SFIO)
-#define PerlIO FILE
+/* #define PerlIO FILE */
 #endif
 /*
- * This file provides those parts of PerlIO abstraction 
+ * This file provides those parts of PerlIO abstraction
  * which are not #defined in iperlsys.h.
- * Which these are depends on various Configure #ifdef's 
+ * Which these are depends on various Configure #ifdef's
  */
 
 #include "EXTERN.h"
@@ -31,15 +30,15 @@
 
 #if !defined(PERL_IMPLICIT_SYS)
 
-#ifdef PERLIO_IS_STDIO 
+#ifdef PERLIO_IS_STDIO
 
 void
 PerlIO_init(void)
 {
- /* Does nothing (yet) except force this file to be included 
+ /* Does nothing (yet) except force this file to be included
     in perl binary. That allows this file to force inclusion
-    of other functions that may be required by loadable 
-    extensions e.g. for FileHandle::tmpfile  
+    of other functions that may be required by loadable
+    extensions e.g. for FileHandle::tmpfile
  */
 }
 
@@ -57,7 +56,7 @@ PerlIO_tmpfile(void)
 #undef HAS_FSETPOS
 #undef HAS_FGETPOS
 
-/* This section is just to make sure these functions 
+/* This section is just to make sure these functions
    get pulled in from libsfio.a
 */
 
@@ -71,368 +70,1770 @@ PerlIO_tmpfile(void)
 void
 PerlIO_init(void)
 {
- /* Force this file to be included  in perl binary. Which allows 
-  *  this file to force inclusion  of other functions that may be 
-  *  required by loadable  extensions e.g. for FileHandle::tmpfile  
+ /* Force this file to be included  in perl binary. Which allows
+  *  this file to force inclusion  of other functions that may be
+  *  required by loadable  extensions e.g. for FileHandle::tmpfile
   */
 
  /* Hack
   * sfio does its own 'autoflush' on stdout in common cases.
-  * Flush results in a lot of lseek()s to regular files and 
+  * Flush results in a lot of lseek()s to regular files and
   * lot of small writes to pipes.
   */
  sfset(sfstdout,SF_SHARE,0);
 }
 
 #else /* USE_SFIO */
+/*======================================================================================*/
+/* Implement all the PerlIO interface ourselves.
+ */
 
-/* Implement all the PerlIO interface using stdio. 
-   - this should be only file to include <stdio.h>
-*/
+/* We _MUST_ have <unistd.h> if we are using lseek() and may have large files */
+#ifdef I_UNISTD
+#include <unistd.h>
+#endif
+#include "XSUB.h"
+
+#undef printf
+void PerlIO_debug(char *fmt,...) __attribute__((format(printf,1,2)));
+
+void
+PerlIO_debug(char *fmt,...)
+{
+ static int dbg = 0;
+ if (!dbg)
+  {
+   char *s = getenv("PERLIO_DEBUG");
+   if (s && *s)
+    dbg = open(s,O_WRONLY|O_CREAT|O_APPEND,0666);
+   else
+    dbg = -1;
+  }
+ if (dbg > 0)
+  {
+   dTHX;
+   va_list ap;
+   SV *sv = newSVpvn("",0);
+   char *s;
+   STRLEN len;
+   va_start(ap,fmt);
+   s = CopFILE(PL_curcop);
+   if (!s)
+    s = "(none)";
+   Perl_sv_catpvf(aTHX_ sv, "%s:%"IVdf" ", s, (IV)CopLINE(PL_curcop));
+   Perl_sv_vcatpvf(aTHX_ sv, fmt, &ap);
+
+   s = SvPV(sv,len);
+   write(dbg,s,len);
+   va_end(ap);
+   SvREFCNT_dec(sv);
+  }
+}
+
+/*--------------------------------------------------------------------------------------*/
+
+typedef struct
+{
+ char *		name;
+ Size_t		size;
+ IV		kind;
+ IV		(*Fileno)(PerlIO *f);
+ PerlIO *	(*Fdopen)(int fd, const char *mode);
+ PerlIO *	(*Open)(const char *path, const char *mode);
+ int		(*Reopen)(const char *path, const char *mode, PerlIO *f);
+ /* Unix-like functions - cf sfio line disciplines */
+ SSize_t	(*Read)(PerlIO *f, void *vbuf, Size_t count);
+ SSize_t	(*Unread)(PerlIO *f, const void *vbuf, Size_t count);
+ SSize_t	(*Write)(PerlIO *f, const void *vbuf, Size_t count);
+ IV		(*Seek)(PerlIO *f, Off_t offset, int whence);
+ Off_t		(*Tell)(PerlIO *f);
+ IV		(*Close)(PerlIO *f);
+ /* Stdio-like buffered IO functions */
+ IV		(*Flush)(PerlIO *f);
+ IV		(*Eof)(PerlIO *f);
+ IV		(*Error)(PerlIO *f);
+ void		(*Clearerr)(PerlIO *f);
+ void		(*Setlinebuf)(PerlIO *f);
+ /* Perl's snooping functions */
+ STDCHAR *	(*Get_base)(PerlIO *f);
+ Size_t		(*Get_bufsiz)(PerlIO *f);
+ STDCHAR *	(*Get_ptr)(PerlIO *f);
+ SSize_t	(*Get_cnt)(PerlIO *f);
+ void		(*Set_ptrcnt)(PerlIO *f,STDCHAR *ptr,SSize_t cnt);
+} PerlIO_funcs;
+
+
+struct _PerlIO
+{
+ PerlIOl *	next;       /* Lower layer */
+ PerlIO_funcs *	tab;        /* Functions for this layer */
+ IV		flags;      /* Various flags for state */
+};
+
+/*--------------------------------------------------------------------------------------*/
+
+/* Flag values */
+#define PERLIO_F_EOF		0x00010000
+#define PERLIO_F_CANWRITE	0x00020000
+#define PERLIO_F_CANREAD	0x00040000
+#define PERLIO_F_ERROR		0x00080000
+#define PERLIO_F_TRUNCATE	0x00100000
+#define PERLIO_F_APPEND		0x00200000
+#define PERLIO_F_BINARY		0x00400000
+#define PERLIO_F_UTF8		0x00800000
+#define PERLIO_F_LINEBUF	0x01000000
+#define PERLIO_F_WRBUF		0x02000000
+#define PERLIO_F_RDBUF		0x04000000
+#define PERLIO_F_TEMP		0x08000000
+#define PERLIO_F_OPEN		0x10000000
+
+#define PerlIOBase(f)      (*(f))
+#define PerlIOSelf(f,type) ((type *)PerlIOBase(f))
+#define PerlIONext(f)      (&(PerlIOBase(f)->next))
+
+/*--------------------------------------------------------------------------------------*/
+/* Inner level routines */
+
+/* Table of pointers to the PerlIO structs (malloc'ed) */
+PerlIO *_perlio      = NULL;
+#define PERLIO_TABLE_SIZE 64
 
-#undef PerlIO_stderr
 PerlIO *
-PerlIO_stderr(void)
+PerlIO_allocate(void)
 {
- return (PerlIO *) stderr;
+ /* Find a free slot in the table, allocating new table as necessary */
+ PerlIO **last = &_perlio;
+ PerlIO *f;
+ while ((f = *last))
+  {
+   int i;
+   last = (PerlIO **)(f);
+   for (i=1; i < PERLIO_TABLE_SIZE; i++)
+    {
+     if (!*++f)
+      {
+       return f;
+      }
+    }
+  }
+ Newz('I',f,PERLIO_TABLE_SIZE,PerlIO);
+ if (!f)
+  return NULL;
+ *last = f;
+ return f+1;
 }
 
-#undef PerlIO_stdin
+void
+PerlIO_cleantable(PerlIO **tablep)
+{
+ PerlIO *table = *tablep;
+ if (table)
+  {
+   int i;
+   PerlIO_cleantable((PerlIO **) &(table[0]));
+   for (i=PERLIO_TABLE_SIZE-1; i > 0; i--)
+    {
+     PerlIO *f = table+i;
+     if (*f)
+      PerlIO_close(f);
+    }
+   Safefree(table);
+   *tablep = NULL;
+  }
+}
+
+void
+PerlIO_cleanup(void)
+{
+ PerlIO_cleantable(&_perlio);
+}
+
+void
+PerlIO_pop(PerlIO *f)
+{
+ PerlIOl *l = *f;
+ if (l)
+  {
+   *f = l->next;
+   Safefree(l);
+  }
+}
+
+#undef PerlIO_close
+int
+PerlIO_close(PerlIO *f)
+{
+ int code = (*PerlIOBase(f)->tab->Close)(f);
+ while (*f)
+  {
+   PerlIO_pop(f);
+  }
+ return code;
+}
+
+
+/*--------------------------------------------------------------------------------------*/
+/* Given the abstraction above the public API functions */
+
+#undef PerlIO_fileno
+int
+PerlIO_fileno(PerlIO *f)
+{
+ return (*PerlIOBase(f)->tab->Fileno)(f);
+}
+
+
+extern PerlIO_funcs PerlIO_unix;
+extern PerlIO_funcs PerlIO_perlio;
+extern PerlIO_funcs PerlIO_stdio;
+
+XS(XS_perlio_import)
+{
+ dXSARGS;
+ GV *gv = CvGV(cv);
+ char *s = GvNAME(gv);
+ STRLEN l = GvNAMELEN(gv);
+ PerlIO_debug("%.*s\n",(int) l,s);
+ XSRETURN_EMPTY;
+}
+
+XS(XS_perlio_unimport)
+{
+ dXSARGS;
+ GV *gv = CvGV(cv);
+ char *s = GvNAME(gv);
+ STRLEN l = GvNAMELEN(gv);
+ PerlIO_debug("%.*s\n",(int) l,s);
+ XSRETURN_EMPTY;
+}
+
+HV *PerlIO_layer_hv;
+AV *PerlIO_layer_av;
+
+SV *
+PerlIO_find_layer(char *name, STRLEN len)
+{
+ dTHX;
+ SV **svp;
+ SV *sv;
+ if (len <= 0)
+  len = strlen(name);
+ svp  = hv_fetch(PerlIO_layer_hv,name,len,0);
+ if (svp && (sv = *svp) && SvROK(sv))
+  return *svp;
+ return NULL;
+}
+
+void
+PerlIO_define_layer(PerlIO_funcs *tab)
+{
+ dTHX;
+ HV *stash = gv_stashpv("perlio::Layer", TRUE);
+ SV *sv = sv_bless(newRV_noinc(newSViv((IV) tab)),stash);
+ hv_store(PerlIO_layer_hv,tab->name,strlen(tab->name),sv,0);
+}
+
+PerlIO_funcs *
+PerlIO_default_layer(I32 n)
+{
+ dTHX;
+ SV **svp;
+ SV *layer;
+ PerlIO_funcs *tab = &PerlIO_stdio;
+ int len;
+ if (!PerlIO_layer_hv)
+  {
+   char *s  = getenv("PERLIO");
+   newXS("perlio::import",XS_perlio_import,__FILE__);
+   newXS("perlio::unimport",XS_perlio_unimport,__FILE__);
+   PerlIO_layer_hv = get_hv("perlio::layers",GV_ADD|GV_ADDMULTI);
+   PerlIO_layer_av = get_av("perlio::layers",GV_ADD|GV_ADDMULTI);
+   PerlIO_define_layer(&PerlIO_unix);
+   PerlIO_define_layer(&PerlIO_unix);
+   PerlIO_define_layer(&PerlIO_perlio);
+   PerlIO_define_layer(&PerlIO_stdio);
+   av_push(PerlIO_layer_av,SvREFCNT_inc(PerlIO_find_layer(PerlIO_unix.name,0)));
+   if (s)
+    {
+     while (*s)
+      {
+       while (*s && isspace((unsigned char)*s))
+        s++;
+       if (*s)
+        {
+         char *e = s;
+         SV *layer;
+         while (*e && !isspace((unsigned char)*e))
+          e++;
+         layer = PerlIO_find_layer(s,e-s);
+         if (layer)
+          {
+           PerlIO_debug("Pushing %.*s\n",(e-s),s);
+           av_push(PerlIO_layer_av,SvREFCNT_inc(layer));
+          }
+         else
+          Perl_croak(aTHX_ "Unknown layer %.*s",(e-s),s);
+         s = e;
+        }
+      }
+    }
+  }
+ len  = av_len(PerlIO_layer_av);
+ if (len < 1)
+  {
+   if (PerlIO_stdio.Set_ptrcnt)
+    {
+     av_push(PerlIO_layer_av,SvREFCNT_inc(PerlIO_find_layer(PerlIO_stdio.name,0)));
+    }
+   else
+    {
+     av_push(PerlIO_layer_av,SvREFCNT_inc(PerlIO_find_layer(PerlIO_perlio.name,0)));
+    }
+   len  = av_len(PerlIO_layer_av);
+  }
+ if (n < 0)
+  n += len+1;
+ svp = av_fetch(PerlIO_layer_av,n,0);
+ if (svp && (layer = *svp) && SvROK(layer) && SvIOK((layer = SvRV(layer))))
+  {
+   tab = (PerlIO_funcs *) SvIV(layer);
+  }
+ /* PerlIO_debug("Layer %d is %s\n",n,tab->name); */
+ return tab;
+}
+
+#define PerlIO_default_top() PerlIO_default_layer(-1)
+#define PerlIO_default_btm() PerlIO_default_layer(0)
+
+void
+PerlIO_stdstreams()
+{
+ if (!_perlio)
+  {
+   PerlIO_allocate();
+   PerlIO_fdopen(0,"Ir");
+   PerlIO_fdopen(1,"Iw");
+   PerlIO_fdopen(2,"Iw");
+  }
+}
+
+#undef PerlIO_fdopen
 PerlIO *
-PerlIO_stdin(void)
+PerlIO_fdopen(int fd, const char *mode)
 {
- return (PerlIO *) stdin;
+ PerlIO_funcs *tab = PerlIO_default_top();
+ if (!_perlio)
+  PerlIO_stdstreams();
+ return (*tab->Fdopen)(fd,mode);
 }
 
-#undef PerlIO_stdout
+#undef PerlIO_open
 PerlIO *
-PerlIO_stdout(void)
+PerlIO_open(const char *path, const char *mode)
+{
+ PerlIO_funcs *tab = PerlIO_default_top();
+ if (!_perlio)
+  PerlIO_stdstreams();
+ return (*tab->Open)(path,mode);
+}
+
+IV
+PerlIOBase_init(PerlIO *f, const char *mode)
+{
+ PerlIOl *l = PerlIOBase(f);
+ l->flags  &= ~(PERLIO_F_CANREAD|PERLIO_F_CANWRITE|
+                PERLIO_F_TRUNCATE|PERLIO_F_APPEND|PERLIO_F_BINARY);
+ if (mode)
+  {
+   switch (*mode++)
+    {
+     case 'r':
+      l->flags = PERLIO_F_CANREAD;
+      break;
+     case 'a':
+      l->flags = PERLIO_F_APPEND|PERLIO_F_CANWRITE;
+      break;
+     case 'w':
+      l->flags = PERLIO_F_TRUNCATE|PERLIO_F_CANWRITE;
+      break;
+     default:
+      errno = EINVAL;
+      return -1;
+    }
+   while (*mode)
+    {
+     switch (*mode++)
+      {
+       case '+':
+        l->flags |= PERLIO_F_CANREAD|PERLIO_F_CANWRITE;
+        break;
+       case 'b':
+        l->flags |= PERLIO_F_BINARY;
+        break;
+      default:
+       errno = EINVAL;
+       return -1;
+      }
+    }
+  }
+ else
+  {
+   if (l->next)
+    {
+     l->flags |= l->next->flags &
+                 (PERLIO_F_CANREAD|PERLIO_F_CANWRITE|
+                   PERLIO_F_TRUNCATE|PERLIO_F_APPEND|PERLIO_F_BINARY);
+    }
+  }
+ return 0;
+}
+
+#undef PerlIO_reopen
+PerlIO *
+PerlIO_reopen(const char *path, const char *mode, PerlIO *f)
+{
+ if (f)
+  {
+   PerlIO_flush(f);
+   if ((*PerlIOBase(f)->tab->Reopen)(path,mode,f) == 0)
+    {
+     PerlIOBase_init(f,mode);
+     return f;
+    }
+   return NULL;
+  }
+ else
+  return PerlIO_open(path,mode);
+}
+
+#undef PerlIO_read
+SSize_t
+PerlIO_read(PerlIO *f, void *vbuf, Size_t count)
+{
+ return (*PerlIOBase(f)->tab->Read)(f,vbuf,count);
+}
+
+#undef PerlIO_ungetc
+int
+PerlIO_ungetc(PerlIO *f, int ch)
+{
+ STDCHAR buf = ch;
+ if ((*PerlIOBase(f)->tab->Unread)(f,&buf,1) == 1)
+  return ch;
+ return -1;
+}
+
+#undef PerlIO_write
+SSize_t
+PerlIO_write(PerlIO *f, const void *vbuf, Size_t count)
+{
+ return (*PerlIOBase(f)->tab->Write)(f,vbuf,count);
+}
+
+#undef PerlIO_seek
+int
+PerlIO_seek(PerlIO *f, Off_t offset, int whence)
+{
+ return (*PerlIOBase(f)->tab->Seek)(f,offset,whence);
+}
+
+#undef PerlIO_tell
+Off_t
+PerlIO_tell(PerlIO *f)
+{
+ return (*PerlIOBase(f)->tab->Tell)(f);
+}
+
+#undef PerlIO_flush
+int
+PerlIO_flush(PerlIO *f)
+{
+ if (f)
+  {
+   return (*PerlIOBase(f)->tab->Flush)(f);
+  }
+ else
+  {
+   PerlIO **table = &_perlio;
+   int code = 0;
+   while ((f = *table))
+    {
+     int i;
+     table = (PerlIO **)(f++);
+     for (i=1; i < PERLIO_TABLE_SIZE; i++)
+      {
+       if (*f && PerlIO_flush(f) != 0)
+        code = -1;
+       f++;
+      }
+    }
+   return code;
+  }
+}
+
+#undef PerlIO_isutf8
+int
+PerlIO_isutf8(PerlIO *f)
+{
+ return (PerlIOBase(f)->flags & PERLIO_F_UTF8) != 0;
+}
+
+#undef PerlIO_eof
+int
+PerlIO_eof(PerlIO *f)
+{
+ return (*PerlIOBase(f)->tab->Eof)(f);
+}
+
+#undef PerlIO_error
+int
+PerlIO_error(PerlIO *f)
 {
- return (PerlIO *) stdout;
+ return (*PerlIOBase(f)->tab->Error)(f);
+}
+
+#undef PerlIO_clearerr
+void
+PerlIO_clearerr(PerlIO *f)
+{
+ (*PerlIOBase(f)->tab->Clearerr)(f);
+}
+
+#undef PerlIO_setlinebuf
+void
+PerlIO_setlinebuf(PerlIO *f)
+{
+ (*PerlIOBase(f)->tab->Setlinebuf)(f);
+}
+
+#undef PerlIO_has_base
+int
+PerlIO_has_base(PerlIO *f)
+{
+ if (f && *f)
+  {
+   return (PerlIOBase(f)->tab->Get_base != NULL);
+  }
+ return 0;
 }
 
 #undef PerlIO_fast_gets
-int 
+int
 PerlIO_fast_gets(PerlIO *f)
 {
-#if defined(USE_STDIO_PTR) && defined(STDIO_PTR_LVALUE) && defined(STDIO_CNT_LVALUE)
- return 1;
-#else
+ if (f && *f)
+  {
+   PerlIOl *l = PerlIOBase(f);
+   return (l->tab->Set_ptrcnt != NULL);
+  }
  return 0;
-#endif
 }
 
 #undef PerlIO_has_cntptr
-int 
+int
 PerlIO_has_cntptr(PerlIO *f)
 {
-#if defined(USE_STDIO_PTR)
- return 1;
-#else
+ if (f && *f)
+  {
+   PerlIO_funcs *tab = PerlIOBase(f)->tab;
+   return (tab->Get_ptr != NULL && tab->Get_cnt != NULL);
+  }
  return 0;
-#endif
 }
 
 #undef PerlIO_canset_cnt
-int 
+int
 PerlIO_canset_cnt(PerlIO *f)
 {
-#if defined(USE_STDIO_PTR) && defined(STDIO_CNT_LVALUE)
- return 1;
-#else
+ if (f && *f)
+  {
+   PerlIOl *l = PerlIOBase(f);
+   return (l->tab->Set_ptrcnt != NULL);
+  }
  return 0;
-#endif
+}
+
+#undef PerlIO_get_base
+STDCHAR *
+PerlIO_get_base(PerlIO *f)
+{
+ return (*PerlIOBase(f)->tab->Get_base)(f);
+}
+
+#undef PerlIO_get_bufsiz
+int
+PerlIO_get_bufsiz(PerlIO *f)
+{
+ return (*PerlIOBase(f)->tab->Get_bufsiz)(f);
+}
+
+#undef PerlIO_get_ptr
+STDCHAR *
+PerlIO_get_ptr(PerlIO *f)
+{
+ return (*PerlIOBase(f)->tab->Get_ptr)(f);
+}
+
+#undef PerlIO_get_cnt
+int
+PerlIO_get_cnt(PerlIO *f)
+{
+ return (*PerlIOBase(f)->tab->Get_cnt)(f);
 }
 
 #undef PerlIO_set_cnt
 void
-PerlIO_set_cnt(PerlIO *f, int cnt)
+PerlIO_set_cnt(PerlIO *f,int cnt)
 {
- dTHX;
- if (cnt < -1 && ckWARN_d(WARN_INTERNAL))
-  Perl_warner(aTHX_ WARN_INTERNAL, "Setting cnt to %d\n",cnt);
-#if defined(USE_STDIO_PTR) && defined(STDIO_CNT_LVALUE)
- FILE_cnt(f) = cnt;
-#else
- Perl_croak(aTHX_ "Cannot set 'cnt' of FILE * on this system");
-#endif
+ (*PerlIOBase(f)->tab->Set_ptrcnt)(f,NULL,cnt);
 }
 
 #undef PerlIO_set_ptrcnt
 void
 PerlIO_set_ptrcnt(PerlIO *f, STDCHAR *ptr, int cnt)
 {
- dTHX;
-#ifdef FILE_bufsiz
- STDCHAR *e = FILE_base(f) + FILE_bufsiz(f);
- int ec = e - ptr;
- if (ptr > e + 1 && ckWARN_d(WARN_INTERNAL))
-  Perl_warner(aTHX_ WARN_INTERNAL, "Setting ptr %p > end+1 %p\n", ptr, e + 1);
- if (cnt != ec && ckWARN_d(WARN_INTERNAL))
-  Perl_warner(aTHX_ WARN_INTERNAL, "Setting cnt to %d, ptr implies %d\n",cnt,ec);
-#endif
-#if defined(USE_STDIO_PTR) && defined(STDIO_PTR_LVALUE)
-  FILE_ptr(f) = ptr;
-#else
-  Perl_croak(aTHX_ "Cannot set 'ptr' of FILE * on this system");
-#endif
-#if defined(USE_STDIO_PTR) && defined(STDIO_CNT_LVALUE) && defined (STDIO_PTR_LVAL_NOCHANGE_CNT)
-  FILE_cnt(f) = cnt;
-#else
-#if defined(STDIO_PTR_LVAL_SETS_CNT)
-  assert (FILE_cnt(f) == cnt);
-#else
-  Perl_croak(aTHX_ "Cannot set 'cnt' of FILE * on this system when setting 'ptr'");
-#endif
-#endif
+ (*PerlIOBase(f)->tab->Set_ptrcnt)(f,ptr,cnt);
 }
 
-#undef PerlIO_get_cnt
-int 
-PerlIO_get_cnt(PerlIO *f)
+/*--------------------------------------------------------------------------------------*/
+/* "Methods" of the "base class" */
+
+IV
+PerlIOBase_fileno(PerlIO *f)
 {
-#ifdef FILE_cnt
- return FILE_cnt(f);
-#else
- dTHX;
- Perl_croak(aTHX_ "Cannot get 'cnt' of FILE * on this system");
- return -1;
-#endif
+ return PerlIO_fileno(PerlIONext(f));
 }
 
-#undef PerlIO_get_bufsiz
-int 
-PerlIO_get_bufsiz(PerlIO *f)
+PerlIO *
+PerlIO_push(PerlIO *f,PerlIO_funcs *tab,const char *mode)
 {
-#ifdef FILE_bufsiz
- return FILE_bufsiz(f);
-#else
- dTHX;
- Perl_croak(aTHX_ "Cannot get 'bufsiz' of FILE * on this system");
+ PerlIOl *l = NULL;
+ Newc('L',l,tab->size,char,PerlIOl);
+ if (l)
+  {
+   Zero(l,tab->size,char);
+   l->next = *f;
+   l->tab  = tab;
+   *f      = l;
+   PerlIOBase_init(f,mode);
+  }
+ return f;
+}
+
+SSize_t
+PerlIOBase_unread(PerlIO *f, const void *vbuf, Size_t count)
+{
+ Off_t old = PerlIO_tell(f);
+ if (PerlIO_seek(f,-((Off_t)count),SEEK_CUR) == 0)
+  {
+   Off_t new = PerlIO_tell(f);
+   return old - new;
+  }
+ return 0;
+}
+
+IV
+PerlIOBase_sync(PerlIO *f)
+{
+ return 0;
+}
+
+IV
+PerlIOBase_close(PerlIO *f)
+{
+ IV code = 0;
+ if (PerlIO_flush(f) != 0)
+  code = -1;
+ if (PerlIO_close(PerlIONext(f)) != 0)
+  code = -1;
+ PerlIOBase(f)->flags &= ~(PERLIO_F_CANREAD|PERLIO_F_CANWRITE|PERLIO_F_OPEN);
+ return code;
+}
+
+IV
+PerlIOBase_eof(PerlIO *f)
+{
+ if (f && *f)
+  {
+   return (PerlIOBase(f)->flags & PERLIO_F_EOF) != 0;
+  }
+ return 1;
+}
+
+IV
+PerlIOBase_error(PerlIO *f)
+{
+ if (f && *f)
+  {
+   return (PerlIOBase(f)->flags & PERLIO_F_ERROR) != 0;
+  }
+ return 1;
+}
+
+void
+PerlIOBase_clearerr(PerlIO *f)
+{
+ if (f && *f)
+  {
+   PerlIOBase(f)->flags &= ~PERLIO_F_ERROR;
+  }
+}
+
+void
+PerlIOBase_setlinebuf(PerlIO *f)
+{
+
+}
+
+
+
+/*--------------------------------------------------------------------------------------*/
+/* Bottom-most level for UNIX-like case */
+
+typedef struct
+{
+ struct _PerlIO base;       /* The generic part */
+ int		fd;         /* UNIX like file descriptor */
+ int		oflags;     /* open/fcntl flags */
+} PerlIOUnix;
+
+int
+PerlIOUnix_oflags(const char *mode)
+{
+ int oflags = -1;
+ switch(*mode)
+  {
+   case 'r':
+    oflags = O_RDONLY;
+    if (*++mode == '+')
+     {
+      oflags = O_RDWR;
+      mode++;
+     }
+    break;
+
+   case 'w':
+    oflags = O_CREAT|O_TRUNC;
+    if (*++mode == '+')
+     {
+      oflags |= O_RDWR;
+      mode++;
+     }
+    else
+     oflags |= O_WRONLY;
+    break;
+
+   case 'a':
+    oflags = O_CREAT|O_APPEND;
+    if (*++mode == '+')
+     {
+      oflags |= O_RDWR;
+      mode++;
+     }
+    else
+     oflags |= O_WRONLY;
+    break;
+  }
+ if (*mode || oflags == -1)
+  {
+   errno = EINVAL;
+   oflags = -1;
+  }
+ return oflags;
+}
+
+IV
+PerlIOUnix_fileno(PerlIO *f)
+{
+ return PerlIOSelf(f,PerlIOUnix)->fd;
+}
+
+PerlIO *
+PerlIOUnix_fdopen(int fd,const char *mode)
+{
+ PerlIO *f = NULL;
+ if (*mode == 'I')
+  mode++;
+ if (fd >= 0)
+  {
+   int oflags = PerlIOUnix_oflags(mode);
+   if (oflags != -1)
+    {
+     PerlIOUnix *s = PerlIOSelf(PerlIO_push(f = PerlIO_allocate(),&PerlIO_unix,mode),PerlIOUnix);
+     s->fd     = fd;
+     s->oflags = oflags;
+     PerlIOBase(f)->flags |= PERLIO_F_OPEN;
+    }
+  }
+ return f;
+}
+
+PerlIO *
+PerlIOUnix_open(const char *path,const char *mode)
+{
+ PerlIO *f = NULL;
+ int oflags = PerlIOUnix_oflags(mode);
+ if (oflags != -1)
+  {
+   int fd = open(path,oflags,0666);
+   if (fd >= 0)
+    {
+     PerlIOUnix *s = PerlIOSelf(PerlIO_push(f = PerlIO_allocate(),&PerlIO_unix,mode),PerlIOUnix);
+     s->fd     = fd;
+     s->oflags = oflags;
+     PerlIOBase(f)->flags |= PERLIO_F_OPEN;
+    }
+  }
+ return f;
+}
+
+int
+PerlIOUnix_reopen(const char *path, const char *mode, PerlIO *f)
+{
+ PerlIOUnix *s = PerlIOSelf(f,PerlIOUnix);
+ int oflags = PerlIOUnix_oflags(mode);
+ if (PerlIOBase(f)->flags & PERLIO_F_OPEN)
+  (*PerlIOBase(f)->tab->Close)(f);
+ if (oflags != -1)
+  {
+   int fd = open(path,oflags,0666);
+   if (fd >= 0)
+    {
+     s->fd = fd;
+     s->oflags = oflags;
+     PerlIOBase(f)->flags |= PERLIO_F_OPEN;
+     return 0;
+    }
+  }
  return -1;
-#endif
 }
 
-#undef PerlIO_get_ptr
-STDCHAR *
-PerlIO_get_ptr(PerlIO *f)
+SSize_t
+PerlIOUnix_read(PerlIO *f, void *vbuf, Size_t count)
 {
-#ifdef FILE_ptr
- return FILE_ptr(f);
+ int fd = PerlIOSelf(f,PerlIOUnix)->fd;
+ while (1)
+  {
+   SSize_t len = read(fd,vbuf,count);
+   if (len >= 0 || errno != EINTR)
+    return len;
+  }
+}
+
+SSize_t
+PerlIOUnix_write(PerlIO *f, const void *vbuf, Size_t count)
+{
+ int fd = PerlIOSelf(f,PerlIOUnix)->fd;
+ while (1)
+  {
+   SSize_t len = write(fd,vbuf,count);
+   if (len >= 0 || errno != EINTR)
+    return len;
+  }
+}
+
+IV
+PerlIOUnix_seek(PerlIO *f, Off_t offset, int whence)
+{
+ Off_t new = lseek(PerlIOSelf(f,PerlIOUnix)->fd,offset,whence);
+ return (new == (Off_t) -1) ? -1 : 0;
+}
+
+Off_t
+PerlIOUnix_tell(PerlIO *f)
+{
+ return lseek(PerlIOSelf(f,PerlIOUnix)->fd,0,SEEK_CUR);
+}
+
+IV
+PerlIOUnix_close(PerlIO *f)
+{
+ int fd = PerlIOSelf(f,PerlIOUnix)->fd;
+ int code = 0;
+ while (close(fd) != 0)
+  {
+   if (errno != EINTR)
+    {
+     code = -1;
+     break;
+    }
+  }
+ if (code == 0)
+  {
+   PerlIOBase(f)->flags &= ~PERLIO_F_OPEN;
+  }
+ return code;
+}
+
+PerlIO_funcs PerlIO_unix = {
+ "unix",
+ sizeof(PerlIOUnix),
+ 0,
+ PerlIOUnix_fileno,
+ PerlIOUnix_fdopen,
+ PerlIOUnix_open,
+ PerlIOUnix_reopen,
+ PerlIOUnix_read,
+ PerlIOBase_unread,
+ PerlIOUnix_write,
+ PerlIOUnix_seek,
+ PerlIOUnix_tell,
+ PerlIOUnix_close,
+ PerlIOBase_sync,
+ PerlIOBase_eof,
+ PerlIOBase_error,
+ PerlIOBase_clearerr,
+ PerlIOBase_setlinebuf,
+ NULL, /* get_base */
+ NULL, /* get_bufsiz */
+ NULL, /* get_ptr */
+ NULL, /* get_cnt */
+ NULL, /* set_ptrcnt */
+};
+
+/*--------------------------------------------------------------------------------------*/
+/* stdio as a layer */
+
+typedef struct
+{
+ struct _PerlIO	base;
+ FILE *		stdio;      /* The stream */
+} PerlIOStdio;
+
+IV
+PerlIOStdio_fileno(PerlIO *f)
+{
+ return fileno(PerlIOSelf(f,PerlIOStdio)->stdio);
+}
+
+
+PerlIO *
+PerlIOStdio_fdopen(int fd,const char *mode)
+{
+ PerlIO *f = NULL;
+ int init = 0;
+ if (*mode == 'I')
+  {
+   init = 1;
+   mode++;
+  }
+ if (fd >= 0)
+  {
+   FILE *stdio = NULL;
+   if (init)
+    {
+     switch(fd)
+      {
+       case 0:
+        stdio = stdin;
+        break;
+       case 1:
+        stdio = stdout;
+        break;
+       case 2:
+        stdio = stderr;
+        break;
+      }
+    }
+   else
+    stdio = fdopen(fd,mode);
+   if (stdio)
+    {
+     PerlIOStdio *s = PerlIOSelf(PerlIO_push(f = PerlIO_allocate(),&PerlIO_stdio,mode),PerlIOStdio);
+     s->stdio  = stdio;
+    }
+  }
+ return f;
+}
+
+#undef PerlIO_importFILE
+PerlIO *
+PerlIO_importFILE(FILE *stdio, int fl)
+{
+ PerlIO *f = NULL;
+ if (stdio)
+  {
+   PerlIOStdio *s = PerlIOSelf(PerlIO_push(f = PerlIO_allocate(),&PerlIO_stdio,"r+"),PerlIOStdio);
+   s->stdio  = stdio;
+  }
+ return f;
+}
+
+PerlIO *
+PerlIOStdio_open(const char *path,const char *mode)
+{
+ PerlIO *f = NULL;
+ FILE *stdio = fopen(path,mode);
+ if (stdio)
+  {
+   PerlIOStdio *s = PerlIOSelf(PerlIO_push(f = PerlIO_allocate(),&PerlIO_stdio,mode),PerlIOStdio);
+   s->stdio  = stdio;
+  }
+ return f;
+}
+
+int
+PerlIOStdio_reopen(const char *path, const char *mode, PerlIO *f)
+{
+ PerlIOStdio *s = PerlIOSelf(f,PerlIOStdio);
+ FILE *stdio = freopen(path,mode,s->stdio);
+ if (!s->stdio)
+  return -1;
+ s->stdio = stdio;
+ return 0;
+}
+
+SSize_t
+PerlIOStdio_read(PerlIO *f, void *vbuf, Size_t count)
+{
+ FILE *s = PerlIOSelf(f,PerlIOStdio)->stdio;
+ SSize_t got = 0;
+ if (count == 1)
+  {
+   STDCHAR *buf = (STDCHAR *) vbuf;
+   /* Perl is expecting PerlIO_getc() to fill the buffer
+    * Linux's stdio does not do that for fread()
+    */
+   int ch = fgetc(s);
+   if (ch != EOF)
+    {
+     *buf = ch;
+     got = 1;
+    }
+  }
+ else
+  got = fread(vbuf,1,count,s);
+ return got;
+}
+
+SSize_t
+PerlIOStdio_unread(PerlIO *f, const void *vbuf, Size_t count)
+{
+ FILE *s = PerlIOSelf(f,PerlIOStdio)->stdio;
+ STDCHAR *buf = ((STDCHAR *)vbuf)+count-1;
+ SSize_t unread = 0;
+ while (count > 0)
+  {
+   int ch = *buf-- & 0xff;
+   if (ungetc(ch,s) != ch)
+    break;
+   unread++;
+   count--;
+  }
+ return unread;
+}
+
+SSize_t
+PerlIOStdio_write(PerlIO *f, const void *vbuf, Size_t count)
+{
+ return fwrite(vbuf,1,count,PerlIOSelf(f,PerlIOStdio)->stdio);
+}
+
+IV
+PerlIOStdio_seek(PerlIO *f, Off_t offset, int whence)
+{
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return fseek(stdio,offset,whence);
+}
+
+Off_t
+PerlIOStdio_tell(PerlIO *f)
+{
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return ftell(stdio);
+}
+
+IV
+PerlIOStdio_close(PerlIO *f)
+{
+ return fclose(PerlIOSelf(f,PerlIOStdio)->stdio);
+}
+
+IV
+PerlIOStdio_flush(PerlIO *f)
+{
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return fflush(stdio);
+}
+
+IV
+PerlIOStdio_eof(PerlIO *f)
+{
+ return feof(PerlIOSelf(f,PerlIOStdio)->stdio);
+}
+
+IV
+PerlIOStdio_error(PerlIO *f)
+{
+ return ferror(PerlIOSelf(f,PerlIOStdio)->stdio);
+}
+
+void
+PerlIOStdio_clearerr(PerlIO *f)
+{
+ clearerr(PerlIOSelf(f,PerlIOStdio)->stdio);
+}
+
+void
+PerlIOStdio_setlinebuf(PerlIO *f)
+{
+#ifdef HAS_SETLINEBUF
+ setlinebuf(PerlIOSelf(f,PerlIOStdio)->stdio);
 #else
- dTHX;
- Perl_croak(aTHX_ "Cannot get 'ptr' of FILE * on this system");
- return NULL;
+ setvbuf(PerlIOSelf(f,PerlIOStdio)->stdio, Nullch, _IOLBF, 0);
 #endif
 }
 
-#undef PerlIO_get_base
+#ifdef FILE_base
 STDCHAR *
-PerlIO_get_base(PerlIO *f)
+PerlIOStdio_get_base(PerlIO *f)
 {
-#ifdef FILE_base
- return FILE_base(f);
-#else
- dTHX;
- Perl_croak(aTHX_ "Cannot get 'base' of FILE * on this system");
- return NULL;
+ FILE *stdio  = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return FILE_base(stdio);
+}
+
+Size_t
+PerlIOStdio_get_bufsiz(PerlIO *f)
+{
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return FILE_bufsiz(stdio);
+}
 #endif
+
+#ifdef USE_STDIO_PTR
+STDCHAR *
+PerlIOStdio_get_ptr(PerlIO *f)
+{
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return FILE_ptr(stdio);
 }
 
-#undef PerlIO_has_base 
-int 
-PerlIO_has_base(PerlIO *f)
+SSize_t
+PerlIOStdio_get_cnt(PerlIO *f)
+{
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return FILE_cnt(stdio);
+}
+
+void
+PerlIOStdio_set_ptrcnt(PerlIO *f,STDCHAR *ptr,SSize_t cnt)
 {
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ if (ptr != NULL)
+  {
+#ifdef STDIO_PTR_LVALUE
+   FILE_ptr(stdio) = ptr;
+#ifdef STDIO_PTR_LVAL_SETS_CNT
+   if (FILE_cnt(stdio) != (cnt))
+    {
+     dTHX;
+     assert(FILE_cnt(stdio) == (cnt));
+    }
+#endif
+#if (!defined(STDIO_PTR_LVAL_NOCHANGE_CNT))
+   /* Setting ptr _does_ change cnt - we are done */
+   return;
+#endif
+#else  /* STDIO_PTR_LVALUE */
+   abort();
+#endif /* STDIO_PTR_LVALUE */
+  }
+/* Now (or only) set cnt */
+#ifdef STDIO_CNT_LVALUE
+ FILE_cnt(stdio) = cnt;
+#else  /* STDIO_CNT_LVALUE */
+#if (defined(STDIO_PTR_LVALUE) && defined(STDIO_PTR_LVAL_SETS_CNT))
+ FILE_ptr(stdio) = FILE_ptr(stdio)+(FILE_cnt(stdio)-cnt);
+#else  /* STDIO_PTR_LVAL_SETS_CNT */
+ abort();
+#endif /* STDIO_PTR_LVAL_SETS_CNT */
+#endif /* STDIO_CNT_LVALUE */
+}
+
+#endif
+
+PerlIO_funcs PerlIO_stdio = {
+ "stdio",
+ sizeof(PerlIOStdio),
+ 0,
+ PerlIOStdio_fileno,
+ PerlIOStdio_fdopen,
+ PerlIOStdio_open,
+ PerlIOStdio_reopen,
+ PerlIOStdio_read,
+ PerlIOStdio_unread,
+ PerlIOStdio_write,
+ PerlIOStdio_seek,
+ PerlIOStdio_tell,
+ PerlIOStdio_close,
+ PerlIOStdio_flush,
+ PerlIOStdio_eof,
+ PerlIOStdio_error,
+ PerlIOStdio_clearerr,
+ PerlIOStdio_setlinebuf,
 #ifdef FILE_base
- return 1;
+ PerlIOStdio_get_base,
+ PerlIOStdio_get_bufsiz,
 #else
- return 0;
+ NULL,
+ NULL,
 #endif
+#ifdef USE_STDIO_PTR
+ PerlIOStdio_get_ptr,
+ PerlIOStdio_get_cnt,
+#if (defined(STDIO_PTR_LVALUE) && \
+    (defined(STDIO_CNT_LVALUE) || defined(STDIO_PTR_LVAL_SETS_CNT)))
+ PerlIOStdio_set_ptrcnt
+#else  /* STDIO_PTR_LVALUE */
+ NULL
+#endif /* STDIO_PTR_LVALUE */
+#else  /* USE_STDIO_PTR */
+ NULL,
+ NULL,
+ NULL
+#endif /* USE_STDIO_PTR */
+};
+
+#undef PerlIO_exportFILE
+FILE *
+PerlIO_exportFILE(PerlIO *f, int fl)
+{
+ PerlIO_flush(f);
+ /* Should really push stdio discipline when we have them */
+ return fdopen(PerlIO_fileno(f),"r+");
+}
+
+#undef PerlIO_findFILE
+FILE *
+PerlIO_findFILE(PerlIO *f)
+{
+ return PerlIO_exportFILE(f,0);
+}
+
+#undef PerlIO_releaseFILE
+void
+PerlIO_releaseFILE(PerlIO *p, FILE *f)
+{
+}
+
+/*--------------------------------------------------------------------------------------*/
+/* perlio buffer layer */
+
+typedef struct
+{
+ struct _PerlIO base;
+ Off_t		posn;       /* Offset of buf into the file */
+ STDCHAR *	buf;        /* Start of buffer */
+ STDCHAR *	end;        /* End of valid part of buffer */
+ STDCHAR *	ptr;        /* Current position in buffer */
+ Size_t		bufsiz;     /* Size of buffer */
+ IV		oneword;    /* Emergency buffer */
+} PerlIOBuf;
+
+
+PerlIO *
+PerlIOBuf_fdopen(int fd, const char *mode)
+{
+ PerlIO_funcs *tab = PerlIO_default_btm();
+ int init = 0;
+ PerlIO *f;
+ if (*mode == 'I')
+  {
+   init = 1;
+   mode++;
+  }
+ f = (*tab->Fdopen)(fd,mode);
+ if (f)
+  {
+   /* Initial stderr is unbuffered */
+   if (!init || fd != 2)
+    {
+     PerlIOBuf *b = PerlIOSelf(PerlIO_push(f,&PerlIO_perlio,NULL),PerlIOBuf);
+     b->posn = PerlIO_tell(PerlIONext(f));
+    }
+  }
+ return f;
+}
+
+PerlIO *
+PerlIOBuf_open(const char *path, const char *mode)
+{
+ PerlIO_funcs *tab = PerlIO_default_btm();
+ PerlIO *f = (*tab->Open)(path,mode);
+ if (f)
+  {
+   PerlIOBuf *b = PerlIOSelf(PerlIO_push(f,&PerlIO_perlio,NULL),PerlIOBuf);
+   b->posn = 0;
+  }
+ return f;
 }
 
-#undef PerlIO_puts
 int
-PerlIO_puts(PerlIO *f, const char *s)
+PerlIOBase_reopen(const char *path, const char *mode, PerlIO *f)
 {
- return fputs(s,f);
+ return (*PerlIOBase(f)->tab->Reopen)(path,mode,PerlIONext(f));
 }
 
-#undef PerlIO_open 
-PerlIO * 
-PerlIO_open(const char *path, const char *mode)
+void
+PerlIOBuf_alloc_buf(PerlIOBuf *b)
 {
- return fopen(path,mode);
+ if (!b->bufsiz)
+  b->bufsiz = 4096;
+ New('B',b->buf,b->bufsiz,STDCHAR);
+ if (!b->buf)
+  {
+   b->buf = (STDCHAR *)&b->oneword;
+   b->bufsiz = sizeof(b->oneword);
+  }
+ b->ptr = b->buf;
+ b->end = b->ptr;
 }
 
-#undef PerlIO_fdopen
-PerlIO * 
-PerlIO_fdopen(int fd, const char *mode)
+/* This "flush" is akin to sfio's sync in that it handles files in either
+   read or write state
+*/
+IV
+PerlIOBuf_flush(PerlIO *f)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ int code = 0;
+ if (PerlIOBase(f)->flags & PERLIO_F_WRBUF)
+  {
+   /* write() the buffer */
+   STDCHAR *p = b->buf;
+   int count;
+   while (p < b->ptr)
+    {
+     count = PerlIO_write(PerlIONext(f),p,b->ptr - p);
+     if (count > 0)
+      {
+       p += count;
+      }
+     else if (count < 0)
+      {
+       PerlIOBase(f)->flags |= PERLIO_F_ERROR;
+       code = -1;
+       break;
+      }
+    }
+   b->posn += (p - b->buf);
+  }
+ else if (PerlIOBase(f)->flags & PERLIO_F_RDBUF)
+  {
+   /* Note position change */
+   b->posn += (b->ptr - b->buf);
+   if (b->ptr < b->end)
+    {
+     /* We did not consume all of it */
+     if (PerlIO_seek(PerlIONext(f),b->posn,SEEK_SET) == 0)
+      {
+       b->posn = PerlIO_tell(PerlIONext(f));
+      }
+    }
+  }
+ b->ptr = b->end = b->buf;
+ PerlIOBase(f)->flags &= ~(PERLIO_F_RDBUF|PERLIO_F_WRBUF);
+ if (PerlIO_flush(PerlIONext(f)) != 0)
+  code = -1;
+ return code;
+}
+
+SSize_t
+PerlIOBuf_read(PerlIO *f, void *vbuf, Size_t count)
 {
- return fdopen(fd,mode);
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ STDCHAR *buf = (STDCHAR *) vbuf;
+ if (f)
+  {
+   Size_t got = 0;
+   if (!b->ptr)
+    PerlIOBuf_alloc_buf(b);
+   if (!(PerlIOBase(f)->flags & PERLIO_F_CANREAD))
+    return 0;
+   while (count > 0)
+    {
+     SSize_t avail = (b->end - b->ptr);
+     if ((SSize_t) count < avail)
+      avail = count;
+     if (avail > 0)
+      {
+       Copy(b->ptr,buf,avail,char);
+       got     += avail;
+       b->ptr  += avail;
+       count   -= avail;
+       buf     += avail;
+      }
+     if (count && (b->ptr >= b->end))
+      {
+       PerlIO_flush(f);
+       b->ptr = b->end = b->buf;
+       avail = PerlIO_read(PerlIONext(f),b->ptr,b->bufsiz);
+       if (avail <= 0)
+        {
+         if (avail == 0)
+          PerlIOBase(f)->flags |= PERLIO_F_EOF;
+         else
+          PerlIOBase(f)->flags |= PERLIO_F_ERROR;
+         break;
+        }
+       b->end      = b->buf+avail;
+       PerlIOBase(f)->flags |= PERLIO_F_RDBUF;
+      }
+    }
+   return got;
+  }
+ return 0;
 }
 
-#undef PerlIO_reopen
-PerlIO * 
-PerlIO_reopen(const char *name, const char *mode, PerlIO *f)
+SSize_t
+PerlIOBuf_unread(PerlIO *f, const void *vbuf, Size_t count)
 {
- return freopen(name,mode,f);
+ const STDCHAR *buf = (const STDCHAR *) vbuf+count;
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ SSize_t unread = 0;
+ SSize_t avail;
+ if (!b->buf)
+  PerlIOBuf_alloc_buf(b);
+ if (PerlIOBase(f)->flags & PERLIO_F_WRBUF)
+  PerlIO_flush(f);
+ if (b->buf)
+  {
+   if (PerlIOBase(f)->flags & PERLIO_F_RDBUF)
+    {
+     avail = (b->ptr - b->buf);
+     if (avail > (SSize_t) count)
+      avail = count;
+     b->ptr -= avail;
+    }
+   else
+    {
+     avail = b->bufsiz;
+     if (avail > (SSize_t) count)
+      avail = count;
+     b->end = b->ptr + avail;
+    }
+   if (avail > 0)
+    {
+     buf    -= avail;
+     if (buf != b->ptr)
+      {
+       Copy(buf,b->ptr,avail,char);
+      }
+     count  -= avail;
+     unread += avail;
+     PerlIOBase(f)->flags &= ~ PERLIO_F_EOF;
+    }
+  }
+ return unread;
 }
 
-#undef PerlIO_close
-int      
-PerlIO_close(PerlIO *f)
+SSize_t
+PerlIOBuf_write(PerlIO *f, const void *vbuf, Size_t count)
 {
- return fclose(f);
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ const STDCHAR *buf = (const STDCHAR *) vbuf;
+ Size_t written = 0;
+ if (!b->buf)
+  PerlIOBuf_alloc_buf(b);
+ if (!(PerlIOBase(f)->flags & PERLIO_F_CANWRITE))
+  return 0;
+ while (count > 0)
+  {
+   SSize_t avail = b->bufsiz - (b->ptr - b->buf);
+   if ((SSize_t) count < avail)
+    avail = count;
+   PerlIOBase(f)->flags |= PERLIO_F_WRBUF;
+   if (PerlIOBase(f)->flags & PERLIO_F_LINEBUF)
+    {
+     while (avail > 0)
+      {
+       int ch = *buf++;
+       *(b->ptr)++ = ch;
+       count--;
+       avail--;
+       written++;
+       if (ch == '\n')
+        {
+         PerlIO_flush(f);
+         break;
+        }
+      }
+    }
+   else
+    {
+     if (avail)
+      {
+       Copy(buf,b->ptr,avail,char);
+       count   -= avail;
+       buf     += avail;
+       written += avail;
+       b->ptr  += avail;
+      }
+    }
+   if (b->ptr >= (b->buf + b->bufsiz))
+    PerlIO_flush(f);
+  }
+ return written;
 }
 
-#undef PerlIO_eof
-int      
-PerlIO_eof(PerlIO *f)
+IV
+PerlIOBuf_seek(PerlIO *f, Off_t offset, int whence)
 {
- return feof(f);
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ int code;
+ code = PerlIO_flush(f);
+ if (code == 0)
+  {
+   PerlIOBase(f)->flags &= ~PERLIO_F_EOF;
+   code = PerlIO_seek(PerlIONext(f),offset,whence);
+   if (code == 0)
+    {
+     b->posn = PerlIO_tell(PerlIONext(f));
+    }
+  }
+ return code;
 }
 
-#undef PerlIO_getname
-char *
-PerlIO_getname(PerlIO *f, char *buf)
+Off_t
+PerlIOBuf_tell(PerlIO *f)
 {
-#ifdef VMS
- return fgetname(f,buf);
-#else
- dTHX;
- Perl_croak(aTHX_ "Don't know how to get file name");
- return NULL;
-#endif
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ Off_t posn = b->posn;
+ if (b->buf)
+  posn += (b->ptr - b->buf);
+ return posn;
 }
 
-#undef PerlIO_getc
-int      
-PerlIO_getc(PerlIO *f)
+IV
+PerlIOBuf_close(PerlIO *f)
 {
- return fgetc(f);
+ IV code = PerlIOBase_close(f);
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (b->buf && b->buf != (STDCHAR *) &b->oneword)
+  {
+   Safefree(b->buf);
+  }
+ b->buf = NULL;
+ b->ptr = b->end = b->buf;
+ PerlIOBase(f)->flags &= ~(PERLIO_F_RDBUF|PERLIO_F_WRBUF);
+ return code;
 }
 
-#undef PerlIO_error
-int      
-PerlIO_error(PerlIO *f)
+void
+PerlIOBuf_setlinebuf(PerlIO *f)
 {
- return ferror(f);
+ if (f)
+  {
+   PerlIOBase(f)->flags &= ~PERLIO_F_LINEBUF;
+  }
 }
 
-#undef PerlIO_clearerr
 void
-PerlIO_clearerr(PerlIO *f)
+PerlIOBuf_set_cnt(PerlIO *f, int cnt)
 {
- clearerr(f);
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ dTHX;
+ if (!b->buf)
+  PerlIOBuf_alloc_buf(b);
+ b->ptr = b->end - cnt;
+ assert(b->ptr >= b->buf);
 }
 
-#undef PerlIO_flush
-int      
-PerlIO_flush(PerlIO *f)
+STDCHAR *
+PerlIOBuf_get_ptr(PerlIO *f)
 {
- return Fflush(f);
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (!b->buf)
+  PerlIOBuf_alloc_buf(b);
+ return b->ptr;
 }
 
-#undef PerlIO_fileno
-int      
-PerlIO_fileno(PerlIO *f)
+SSize_t
+PerlIOBuf_get_cnt(PerlIO *f)
 {
- return fileno(f);
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (!b->buf)
+  PerlIOBuf_alloc_buf(b);
+ if (PerlIOBase(f)->flags & PERLIO_F_RDBUF)
+  return (b->end - b->ptr);
+ return 0;
+}
+
+STDCHAR *
+PerlIOBuf_get_base(PerlIO *f)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (!b->buf)
+  PerlIOBuf_alloc_buf(b);
+ return b->buf;
+}
+
+Size_t
+PerlIOBuf_bufsiz(PerlIO *f)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (!b->buf)
+  PerlIOBuf_alloc_buf(b);
+ return (b->end - b->buf);
 }
 
-#undef PerlIO_setlinebuf
 void
-PerlIO_setlinebuf(PerlIO *f)
+PerlIOBuf_set_ptrcnt(PerlIO *f, STDCHAR *ptr, SSize_t cnt)
 {
-#ifdef HAS_SETLINEBUF
-    setlinebuf(f);
-#else
-#  ifdef __BORLANDC__ /* Borland doesn't like NULL size for _IOLBF */
-    setvbuf(f, Nullch, _IOLBF, BUFSIZ);
-#  else
-    setvbuf(f, Nullch, _IOLBF, 0);
-#  endif
-#endif
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (!b->buf)
+  PerlIOBuf_alloc_buf(b);
+ b->ptr = ptr;
+ if (PerlIO_get_cnt(f) != cnt || b->ptr < b->buf)
+  {
+   dTHX;
+   assert(PerlIO_get_cnt(f) == cnt);
+   assert(b->ptr >= b->buf);
+  }
+ PerlIOBase(f)->flags |= PERLIO_F_RDBUF;
 }
 
-#undef PerlIO_putc
-int      
-PerlIO_putc(PerlIO *f, int ch)
+PerlIO_funcs PerlIO_perlio = {
+ "perlio",
+ sizeof(PerlIOBuf),
+ 0,
+ PerlIOBase_fileno,
+ PerlIOBuf_fdopen,
+ PerlIOBuf_open,
+ PerlIOBase_reopen,
+ PerlIOBuf_read,
+ PerlIOBuf_unread,
+ PerlIOBuf_write,
+ PerlIOBuf_seek,
+ PerlIOBuf_tell,
+ PerlIOBuf_close,
+ PerlIOBuf_flush,
+ PerlIOBase_eof,
+ PerlIOBase_error,
+ PerlIOBase_clearerr,
+ PerlIOBuf_setlinebuf,
+ PerlIOBuf_get_base,
+ PerlIOBuf_bufsiz,
+ PerlIOBuf_get_ptr,
+ PerlIOBuf_get_cnt,
+ PerlIOBuf_set_ptrcnt,
+};
+
+void
+PerlIO_init(void)
 {
- return putc(ch,f);
+ if (!_perlio)
+  {
+   atexit(&PerlIO_cleanup);
+  }
 }
 
-#undef PerlIO_ungetc
-int      
-PerlIO_ungetc(PerlIO *f, int ch)
+#undef PerlIO_stdin
+PerlIO *
+PerlIO_stdin(void)
 {
- return ungetc(ch,f);
+ if (!_perlio)
+  PerlIO_stdstreams();
+ return &_perlio[1];
 }
 
-#undef PerlIO_read
-SSize_t
-PerlIO_read(PerlIO *f, void *buf, Size_t count)
+#undef PerlIO_stdout
+PerlIO *
+PerlIO_stdout(void)
 {
- return fread(buf,1,count,f);
+ if (!_perlio)
+  PerlIO_stdstreams();
+ return &_perlio[2];
 }
 
-#undef PerlIO_write
-SSize_t
-PerlIO_write(PerlIO *f, const void *buf, Size_t count)
+#undef PerlIO_stderr
+PerlIO *
+PerlIO_stderr(void)
 {
- return fwrite1(buf,1,count,f);
+ if (!_perlio)
+  PerlIO_stdstreams();
+ return &_perlio[3];
 }
 
-#undef PerlIO_vprintf
-int      
-PerlIO_vprintf(PerlIO *f, const char *fmt, va_list ap)
+/*--------------------------------------------------------------------------------------*/
+
+#undef PerlIO_getname
+char *
+PerlIO_getname(PerlIO *f, char *buf)
 {
- return vfprintf(f,fmt,ap);
+ dTHX;
+ Perl_croak(aTHX_ "Don't know how to get file name");
+ return NULL;
 }
 
-#undef PerlIO_tell
-Off_t
-PerlIO_tell(PerlIO *f)
+
+/*--------------------------------------------------------------------------------------*/
+/* Functions which can be called on any kind of PerlIO implemented
+   in terms of above
+*/
+
+#undef PerlIO_getc
+int
+PerlIO_getc(PerlIO *f)
 {
-#if defined(USE_64_BIT_STDIO) && defined(HAS_FTELLO) && !defined(USE_FTELL64)
- return ftello(f);
-#else
- return ftell(f);
-#endif
+ STDCHAR buf;
+ int count = PerlIO_read(f,&buf,1);
+ if (count == 1)
+  return (unsigned char) buf;
+ return -1;
 }
 
-#undef PerlIO_seek
+#undef PerlIO_putc
 int
-PerlIO_seek(PerlIO *f, Off_t offset, int whence)
+PerlIO_putc(PerlIO *f, int ch)
 {
-#if defined(USE_64_BIT_STDIO) && defined(HAS_FSEEKO) && !defined(USE_FSEEK64)
- return fseeko(f,offset,whence);
-#else
- return fseek(f,offset,whence);
-#endif
+ STDCHAR buf = ch;
+ return PerlIO_write(f,&buf,1);
+}
+
+#undef PerlIO_puts
+int
+PerlIO_puts(PerlIO *f, const char *s)
+{
+ STRLEN len = strlen(s);
+ return PerlIO_write(f,s,len);
 }
 
 #undef PerlIO_rewind
 void
 PerlIO_rewind(PerlIO *f)
 {
- rewind(f);
+ PerlIO_seek(f,(Off_t)0,SEEK_SET);
+ PerlIO_clearerr(f);
+}
+
+#undef PerlIO_vprintf
+int
+PerlIO_vprintf(PerlIO *f, const char *fmt, va_list ap)
+{
+ dTHX;
+ SV *sv = newSVpvn("",0);
+ char *s;
+ STRLEN len;
+ sv_vcatpvf(sv, fmt, &ap);
+ s = SvPV(sv,len);
+ return PerlIO_write(f,s,len);
 }
 
 #undef PerlIO_printf
-int      
+int
 PerlIO_printf(PerlIO *f,const char *fmt,...)
 {
  va_list ap;
  int result;
  va_start(ap,fmt);
- result = vfprintf(f,fmt,ap);
+ result = PerlIO_vprintf(f,fmt,ap);
  va_end(ap);
  return result;
 }
 
 #undef PerlIO_stdoutf
-int      
+int
 PerlIO_stdoutf(const char *fmt,...)
 {
  va_list ap;
@@ -447,55 +1848,41 @@ PerlIO_stdoutf(const char *fmt,...)
 PerlIO *
 PerlIO_tmpfile(void)
 {
- return tmpfile();
-}
-
-#undef PerlIO_importFILE
-PerlIO *
-PerlIO_importFILE(FILE *f, int fl)
-{
- return f;
-}
-
-#undef PerlIO_exportFILE
-FILE *
-PerlIO_exportFILE(PerlIO *f, int fl)
-{
- return f;
-}
-
-#undef PerlIO_findFILE
-FILE *
-PerlIO_findFILE(PerlIO *f)
-{
+ dTHX;
+ /* I have no idea how portable mkstemp() is ... */
+ SV *sv = newSVpv("/tmp/PerlIO_XXXXXX",0);
+ int fd = mkstemp(SvPVX(sv));
+ PerlIO *f = NULL;
+ if (fd >= 0)
+  {
+   f = PerlIO_fdopen(fd,"w+");
+   if (f)
+    {
+     PerlIOBase(f)->flags |= PERLIO_F_TEMP;
+    }
+   unlink(SvPVX(sv));
+   SvREFCNT_dec(sv);
+  }
  return f;
 }
 
-#undef PerlIO_releaseFILE
-void
-PerlIO_releaseFILE(PerlIO *p, FILE *f)
-{
-}
-
-void
-PerlIO_init(void)
-{
- /* Does nothing (yet) except force this file to be included 
-    in perl binary. That allows this file to force inclusion
-    of other functions that may be required by loadable 
-    extensions e.g. for FileHandle::tmpfile  
- */
-}
+#undef HAS_FSETPOS
+#undef HAS_FGETPOS
 
 #endif /* USE_SFIO */
 #endif /* PERLIO_IS_STDIO */
 
+/*======================================================================================*/
+/* Now some functions in terms of above which may be needed even if
+   we are not in true PerlIO mode
+ */
+
 #ifndef HAS_FSETPOS
 #undef PerlIO_setpos
 int
 PerlIO_setpos(PerlIO *f, const Fpos_t *pos)
 {
- return PerlIO_seek(f,*pos,0); 
+ return PerlIO_seek(f,*pos,0);
 }
 #else
 #ifndef PERLIO_IS_STDIO
@@ -554,7 +1941,7 @@ vfprintf(FILE *fd, char *pat, char *args)
 #endif
 
 #ifndef PerlIO_vsprintf
-int 
+int
 PerlIO_vsprintf(char *s, int n, const char *fmt, va_list ap)
 {
  int val = vsprintf(s, fmt, ap);
@@ -572,7 +1959,7 @@ PerlIO_vsprintf(char *s, int n, const char *fmt, va_list ap)
 #endif
 
 #ifndef PerlIO_sprintf
-int      
+int
 PerlIO_sprintf(char *s, int n, const char *fmt,...)
 {
  va_list ap;
diff --git a/pod/perlapi.pod b/pod/perlapi.pod
index 634180f7ef..061f403445 100644
--- a/pod/perlapi.pod
+++ b/pod/perlapi.pod
@@ -3223,10 +3223,10 @@ C<retlen> will be set to the length, in bytes, of that character,
 and the pointer C<s> will be advanced to the end of the character.
 
 If C<s> does not point to a well-formed UTF8 character, the behaviour
-is dependent on the value of C<checking>: if this is true, it is
-assumed that the caller will raise a warning, and this function will
-set C<retlen> to C<-1> and return. If C<checking> is not true, an optional UTF8
-warning is produced.
+is dependent on the value of C<flags>: if it contains UTF8_CHECK_ONLY,
+it is assumed that the caller will raise a warning, and this function
+will set C<retlen> to C<-1> and return.  The C<flags> can also contain
+various flags to allow deviations from the strict UTF-8 encoding.
 
 	U8* s	utf8_to_uv(STRLEN curlen, I32 *retlen, U32 flags)
 
diff --git a/t/lib/b.t b/t/lib/b.t
index 6303d624ed..fca7f4724f 100755
--- a/t/lib/b.t
+++ b/t/lib/b.t
@@ -126,6 +126,7 @@ ok;
 
 chomp($a = `$^X "-I../lib" "-MB::Stash" "-Mwarnings" -e1`);
 $a = join ',', sort split /,/, $a;
+$a =~ s/-uperlio(?:::\w+)?,//g if $Config{'useperlio'} eq 'define';
 $a =~ s/-uWin32,// if $^O eq 'MSWin32';
 $a =~ s/-u(Cwd|File|File::Copy|OS2),//g if $^O eq 'os2';
 $a =~ s/-uCwd,// if $^O eq 'cygwin';