X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/02f66e2f9235025f08502389e56df70aa71733c0..eb73becae469f5299394486e1d7e01e96646e994:/perlio.c

diff --git a/perlio.c b/perlio.c
index 6224b76..8db2b96 100644
--- a/perlio.c
+++ b/perlio.c
@@ -20,7 +20,7 @@
 #endif
 /*
  * This file provides those parts of PerlIO abstraction
- * which are not #defined in iperlsys.h.
+ * which are not #defined in perlio.h.
  * Which these are depends on various Configure #ifdef's
  */
 
@@ -28,7 +28,79 @@
 #define PERL_IN_PERLIO_C
 #include "perl.h"
 
-#if !defined(PERL_IMPLICIT_SYS)
+#undef PerlMemShared_calloc
+#define PerlMemShared_calloc(x,y) calloc(x,y)
+#undef PerlMemShared_free
+#define PerlMemShared_free(x) free(x)
+
+int
+perlsio_binmode(FILE *fp, int iotype, int mode)
+{
+/* This used to be contents of do_binmode in doio.c */
+#ifdef DOSISH
+#  if defined(atarist) || defined(__MINT__)
+    if (!fflush(fp)) {
+	if (mode & O_BINARY)
+	    ((FILE*)fp)->_flag |= _IOBIN;
+	else
+	    ((FILE*)fp)->_flag &= ~ _IOBIN;
+	return 1;
+    }
+    return 0;
+#  else
+    dTHX;
+    if (PerlLIO_setmode(fileno(fp), mode) != -1) {
+#    if defined(WIN32) && defined(__BORLANDC__)
+	/* The translation mode of the stream is maintained independent
+	 * of the translation mode of the fd in the Borland RTL (heavy
+	 * digging through their runtime sources reveal).  User has to
+	 * set the mode explicitly for the stream (though they don't
+	 * document this anywhere). GSAR 97-5-24
+	 */
+	fseek(fp,0L,0);
+	if (mode & O_BINARY)
+	    fp->flags |= _F_BIN;
+	else
+	    fp->flags &= ~ _F_BIN;
+#    endif
+	return 1;
+    }
+    else
+	return 0;
+#  endif
+#else
+#  if defined(USEMYBINMODE)
+    if (my_binmode(fp, iotype, mode) != FALSE)
+	return 1;
+    else
+	return 0;
+#  else
+    return 1;
+#  endif
+#endif
+}
+
+#ifndef PERLIO_LAYERS
+int
+PerlIO_apply_layers(pTHX_ PerlIO *f, const char *mode, const char *names)
+{
+ if (!names || !*names || strEQ(names,":crlf") || strEQ(names,":raw"))
+  {
+   return 0;
+  }
+ Perl_croak(aTHX_ "Cannot apply \"%s\" in non-PerlIO perl",names);
+ /* NOTREACHED */
+ return -1;
+}
+
+int
+PerlIO_binmode(pTHX_ PerlIO *fp, int iotype, int mode, const char *names)
+{
+ return perlsio_binmode(fp,iotype,mode);
+}
+
+#endif
+
 
 #ifdef PERLIO_IS_STDIO
 
@@ -84,708 +156,2903 @@ PerlIO_init(void)
 }
 
 #else /* USE_SFIO */
-
 /*======================================================================================*/
-
 /* Implement all the PerlIO interface ourselves.
-*/
+ */
 
+#include "perliol.h"
+
+/* We _MUST_ have <unistd.h> if we are using lseek() and may have large files */
 #ifdef I_UNISTD
 #include <unistd.h>
 #endif
+#ifdef HAS_MMAP
+#include <sys/mman.h>
+#endif
 
-#undef printf
-void PerlIO_debug(char *fmt,...) __attribute__((format(printf,1,2)));
+#include "XSUB.h"
 
+void PerlIO_debug(const char *fmt,...) __attribute__((format(__printf__,1,2)));
 
 void
-PerlIO_debug(char *fmt,...)
+PerlIO_debug(const char *fmt,...)
 {
+ dTHX;
  static int dbg = 0;
+ va_list ap;
+ va_start(ap,fmt);
  if (!dbg)
   {
-   char *s = getenv("PERLIO_DEBUG");
+   char *s = PerlEnv_getenv("PERLIO_DEBUG");
    if (s && *s)
-    dbg = open(s,O_WRONLY|O_CREAT|O_APPEND,0666);
+    dbg = PerlLIO_open3(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);
-   sv_vcatpvf(sv, fmt, &ap);
+   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);
+   PerlLIO_write(dbg,s,len);
    SvREFCNT_dec(sv);
   }
+ va_end(ap);
 }
 
-#define PERLIO_F_EOF		0x010000
-#define PERLIO_F_ERROR		0x020000
-#define PERLIO_F_LINEBUF	0x040000
-#define PERLIO_F_TEMP		0x080000
-#define PERLIO_F_RDBUF		0x100000
-#define PERLIO_F_WRBUF		0x200000
-#define PERLIO_F_OPEN		0x400000
-#define PERLIO_F_USED		0x800000
-
-struct _PerlIO
-{
- IV       flags;
- IV       fd;         /* Maybe pointer on some OSes */
- int      oflags;     /* open/fcntl flags */
- 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 */
- Off_t    posn;       /* Offset of f->buf into the file */
- int      oneword;
-};
+/*--------------------------------------------------------------------------------------*/
 
-int _perlio_size     = 0;
-PerlIO **_perlio     = NULL;
+/* Inner level routines */
 
-void
-PerlIO_alloc_buf(PerlIO *f)
-{
- if (!f->bufsiz)
-  f->bufsiz = 4096;
- New('B',f->buf,f->bufsiz,char);
- if (!f->buf)
-  {
-   f->buf = (STDCHAR *)&f->oneword;
-   f->bufsiz = sizeof(f->oneword);
-  }
- f->ptr = f->buf;
- f->end = f->ptr;
- PerlIO_debug(__FUNCTION__ " f=%p b=%p p=%p e=%p\n",
-                  f,f->buf,f->ptr,f->end);
-}
+/* Table of pointers to the PerlIO structs (malloc'ed) */
+PerlIO *_perlio      = NULL;
+#define PERLIO_TABLE_SIZE 64
 
-#undef PerlIO_flush
-int
-PerlIO_flush(PerlIO *f)
+PerlIO *
+PerlIO_allocate(pTHX)
 {
- int code = 0;
- if (f)
+ /* Find a free slot in the table, allocating new table as necessary */
+ PerlIO **last;
+ PerlIO *f;
+ last = &_perlio;
+ while ((f = *last))
   {
-   PerlIO_debug(__FUNCTION__ " f=%p flags=%08X c=%d buf=%p ptr=%p\n",
-                f,f->flags,(f->ptr-f->buf),f->buf,f->ptr);
-   if (f->flags & PERLIO_F_WRBUF)
-    {
-     STDCHAR *p = f->buf;
-     int count;
-     while (p < f->ptr)
-      {
-       count = write(f->fd,p,f->ptr - p);
-       if (count > 0)
-        {
-         p += count;
-        }
-       else if (count < 0 && errno != EINTR)
-        {
-         f->flags |= PERLIO_F_ERROR;
-         code = -1;
-         break;
-        }
-      }
-     f->posn += (p - f->buf);
-     PerlIO_debug(__FUNCTION__ "(w) f=%p p=%ld\n",f,(long)f->posn);
-    }
-   else if (f->flags & PERLIO_F_RDBUF)
+   int i;
+   last = (PerlIO **)(f);
+   for (i=1; i < PERLIO_TABLE_SIZE; i++)
     {
-     f->posn += (f->ptr - f->buf);
-     if (f->ptr < f->end)
+     if (!*++f)
       {
-       f->posn = lseek(f->fd,f->posn,SEEK_SET);
+       return f;
       }
-     PerlIO_debug(__FUNCTION__ "(r+) f=%p p=%ld\n",f,(long)f->posn);
-    }
-   else
-    {
-     PerlIO_debug(__FUNCTION__ "(?) f=%p p=%ld\n",f,(long)f->posn);
     }
-   f->ptr = f->end = f->buf;
-   f->flags &= ~(PERLIO_F_RDBUF|PERLIO_F_WRBUF);
   }
- else
+ f = PerlMemShared_calloc(PERLIO_TABLE_SIZE,sizeof(PerlIO));
+ if (!f)
+  {
+   return NULL;
+  }
+ *last = f;
+ return f+1;
+}
+
+void
+PerlIO_cleantable(pTHX_ PerlIO **tablep)
+{
+ PerlIO *table = *tablep;
+ if (table)
   {
    int i;
-   for (i=_perlio_size; i >= 0; i--)
+   PerlIO_cleantable(aTHX_ (PerlIO **) &(table[0]));
+   for (i=PERLIO_TABLE_SIZE-1; i > 0; i--)
     {
-     if ((f = _perlio[i]))
+     PerlIO *f = table+i;
+     if (*f)
       {
-       if (PerlIO_flush(f) != 0)
-        code = -1;
+       PerlIO_close(f);
       }
     }
+   PerlMemShared_free(table);
+   *tablep = NULL;
   }
- return code;
 }
 
-int
-PerlIO_oflags(const char *mode)
+HV *PerlIO_layer_hv;
+AV *PerlIO_layer_av;
+
+void
+PerlIO_cleanup()
 {
- int oflags = -1;
- PerlIO_debug(__FUNCTION__ " %s = ",mode);
- switch(*mode)
+ dTHX;
+ PerlIO_cleantable(aTHX_ &_perlio);
+}
+
+void
+PerlIO_pop(PerlIO *f)
+{
+ dTHX;
+ PerlIOl *l = *f;
+ if (l)
   {
-   case 'r':
-    oflags = O_RDONLY;
-    if (*++mode == '+')
-     {
-      oflags = O_RDWR;
-      mode++;
-     }
-    break;
+   PerlIO_debug("PerlIO_pop f=%p %s\n",f,l->tab->name);
+   (*l->tab->Popped)(f);
+   *f = l->next;
+   PerlMemShared_free(l);
+  }
+}
 
-   case 'w':
-    oflags = O_CREAT|O_TRUNC;
-    if (*++mode == '+')
-     {
-      oflags |= O_RDWR;
-      mode++;
-     }
-    else
-     oflags |= O_WRONLY;
-    break;
+/*--------------------------------------------------------------------------------------*/
+/* XS Interface for perl code */
 
-   case 'a':
-    oflags = O_CREAT|O_APPEND;
-    if (*++mode == '+')
-     {
-      oflags |= O_RDWR;
-      mode++;
-     }
-    else
-     oflags |= O_WRONLY;
-    break;
-  }
- if (*mode || oflags == -1)
+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;
+}
+
+SV *
+PerlIO_find_layer(const char *name, STRLEN len)
+{
+ dTHX;
+ SV **svp;
+ SV *sv;
+ if ((SSize_t) len <= 0)
+  len = strlen(name);
+ svp  = hv_fetch(PerlIO_layer_hv,name,len,0);
+ if (svp && (sv = *svp) && SvROK(sv))
+  return *svp;
+ return NULL;
+}
+
+
+static int
+perlio_mg_set(pTHX_ SV *sv, MAGIC *mg)
+{
+ if (SvROK(sv))
   {
-   errno = EINVAL;
-   oflags = -1;
+   IO *io = GvIOn((GV *)SvRV(sv));
+   PerlIO *ifp = IoIFP(io);
+   PerlIO *ofp = IoOFP(io);
+   AV *av = (AV *) mg->mg_obj;
+   Perl_warn(aTHX_ "set %"SVf" %p %p %p",sv,io,ifp,ofp);
   }
- PerlIO_debug(" %X '%s'\n",oflags,mode);
- return oflags;
+ return 0;
 }
 
-PerlIO *
-PerlIO_allocate(void)
+static int
+perlio_mg_get(pTHX_ SV *sv, MAGIC *mg)
 {
- PerlIO *f;
- int i = 0;
- while (1)
+ if (SvROK(sv))
   {
-   PerlIO **table = _perlio;
-   while (i < _perlio_size)
-    {
-     f = table[i];
-     PerlIO_debug(__FUNCTION__ " try %d %p\n",i,f);
-     if (!f)
-      {
-       Newz('F',f,1,PerlIO);
-       if (!f)
-        return NULL;
-       table[i] = f;
-      }
-     if (!(f->flags & PERLIO_F_USED))
-      {
-       Zero(f,1,PerlIO);
-       f->flags = PERLIO_F_USED;
-       return f;
-      }
-     i++;
-    }
-   Newz('I',table,_perlio_size+16,PerlIO *);
-   if (!table)
-    return NULL;
-   Copy(_perlio,table,_perlio_size,PerlIO *);
-   if (_perlio)
-    Safefree(_perlio);
-   _perlio = table;
-   _perlio_size += 16;
+   IO *io = GvIOn((GV *)SvRV(sv));
+   PerlIO *ifp = IoIFP(io);
+   PerlIO *ofp = IoOFP(io);
+   AV *av = (AV *) mg->mg_obj;
+   Perl_warn(aTHX_ "get %"SVf" %p %p %p",sv,io,ifp,ofp);
   }
+ return 0;
 }
 
-#undef PerlIO_fdopen
-PerlIO *
-PerlIO_fdopen(int fd, const char *mode)
+static int
+perlio_mg_clear(pTHX_ SV *sv, MAGIC *mg)
 {
- PerlIO *f = NULL;
- if (fd >= 0)
+ Perl_warn(aTHX_ "clear %"SVf,sv);
+ return 0;
+}
+
+static int
+perlio_mg_free(pTHX_ SV *sv, MAGIC *mg)
+{
+ Perl_warn(aTHX_ "free %"SVf,sv);
+ return 0;
+}
+
+MGVTBL perlio_vtab = {
+ perlio_mg_get,
+ perlio_mg_set,
+ NULL, /* len */
+ NULL,
+ perlio_mg_free
+};
+
+XS(XS_io_MODIFY_SCALAR_ATTRIBUTES)
+{
+ dXSARGS;
+ SV *sv    = SvRV(ST(1));
+ AV *av    = newAV();
+ MAGIC *mg;
+ int count = 0;
+ int i;
+ sv_magic(sv, (SV *)av, '~', NULL, 0);
+ SvRMAGICAL_off(sv);
+ mg = mg_find(sv,'~');
+ mg->mg_virtual = &perlio_vtab;
+ mg_magical(sv);
+ Perl_warn(aTHX_ "attrib %"SVf,sv);
+ for (i=2; i < items; i++)
   {
-   if ((f = PerlIO_allocate()))
+   STRLEN len;
+   const char *name = SvPV(ST(i),len);
+   SV *layer  = PerlIO_find_layer(name,len);
+   if (layer)
+    {
+     av_push(av,SvREFCNT_inc(layer));
+    }
+   else
     {
-     f->fd     = fd;
-     f->oflags = PerlIO_oflags(mode);
-     f->flags  |= (PERLIO_F_OPEN|PERLIO_F_USED);
+     ST(count) = ST(i);
+     count++;
     }
   }
- PerlIO_debug(__FUNCTION__ " fd=%d m=%s f=%p\n",fd,mode,f);
- return f;
+ SvREFCNT_dec(av);
+ XSRETURN(count);
 }
 
-#undef PerlIO_fileno
-int
-PerlIO_fileno(PerlIO *f)
+void
+PerlIO_define_layer(PerlIO_funcs *tab)
 {
- if (f && (f->flags & PERLIO_F_OPEN))
-  {
-   return f->fd;
-  }
- return -1;
+ dTHX;
+ HV *stash = gv_stashpv("perlio::Layer", TRUE);
+ SV *sv = sv_bless(newRV_noinc(newSViv(PTR2IV(tab))),stash);
+ hv_store(PerlIO_layer_hv,tab->name,strlen(tab->name),sv,0);
 }
 
-#undef PerlIO_close
-int
-PerlIO_close(PerlIO *f)
+PerlIO_funcs *
+PerlIO_default_layer(I32 n)
 {
- int code = 0;
- if (f)
+ dTHX;
+ SV **svp;
+ SV *layer;
+ PerlIO_funcs *tab = &PerlIO_stdio;
+ int len;
+ if (!PerlIO_layer_hv)
   {
-   if (PerlIO_flush(f) != 0)
-    code = -1;
-   while (close(f->fd) != 0)
+   const char *s  = PerlEnv_getenv("PERLIO");
+   newXS("perlio::import",XS_perlio_import,__FILE__);
+   newXS("perlio::unimport",XS_perlio_unimport,__FILE__);
+#if 0
+   newXS("io::MODIFY_SCALAR_ATTRIBUTES",XS_io_MODIFY_SCALAR_ATTRIBUTES,__FILE__);
+#endif
+   PerlIO_layer_hv = get_hv("open::layers",GV_ADD|GV_ADDMULTI);
+   PerlIO_layer_av = get_av("open::layers",GV_ADD|GV_ADDMULTI);
+   PerlIO_define_layer(&PerlIO_unix);
+   PerlIO_define_layer(&PerlIO_perlio);
+   PerlIO_define_layer(&PerlIO_stdio);
+   PerlIO_define_layer(&PerlIO_crlf);
+#ifdef HAS_MMAP
+   PerlIO_define_layer(&PerlIO_mmap);
+#endif
+   av_push(PerlIO_layer_av,SvREFCNT_inc(PerlIO_find_layer(PerlIO_unix.name,0)));
+   if (s)
     {
-     if (errno != EINTR)
+     while (*s)
       {
-       code = -1;
-       break;
+       while (*s && isSPACE((unsigned char)*s))
+        s++;
+       if (*s)
+        {
+         const char *e = s;
+         SV *layer;
+         while (*e && !isSPACE((unsigned char)*e))
+          e++;
+         if (*s == ':')
+          s++;
+         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_warn(aTHX_ "perlio: unknown layer \"%.*s\"",(e-s),s);
+         s = e;
+        }
       }
     }
-   f->flags &= ~PERLIO_F_OPEN;
-   f->fd     = -1;
-   if (f->buf && f->buf != (STDCHAR *) &f->oneword)
+  }
+ len  = av_len(PerlIO_layer_av);
+ if (len < 1)
+  {
+   if (O_BINARY != O_TEXT)
+    {
+     av_push(PerlIO_layer_av,SvREFCNT_inc(PerlIO_find_layer(PerlIO_crlf.name,0)));
+    }
+   else
     {
-     Safefree(f->buf);
+     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)));
+      }
     }
-   f->buf = NULL;
-   f->ptr = f->end = f->buf;
-   f->flags &= ~(PERLIO_F_USED|PERLIO_F_RDBUF|PERLIO_F_WRBUF);
+   len  = av_len(PerlIO_layer_av);
   }
- return code;
+ 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 = INT2PTR(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_cleanup(void)
+PerlIO_stdstreams()
 {
- int i;
- PerlIO_debug(__FUNCTION__ "\n");
- for (i=_perlio_size-1; i >= 0; i--)
+ if (!_perlio)
   {
-   PerlIO *f = _perlio[i];
-   if (f)
-    {
-     PerlIO_close(f);
-     Safefree(f);
-    }
+   dTHX;
+   PerlIO_allocate(aTHX);
+   PerlIO_fdopen(0,"Ir" PERLIO_STDTEXT);
+   PerlIO_fdopen(1,"Iw" PERLIO_STDTEXT);
+   PerlIO_fdopen(2,"Iw" PERLIO_STDTEXT);
   }
- if (_perlio)
-  Safefree(_perlio);
- _perlio      = NULL;
- _perlio_size = 0;
 }
 
-#undef PerlIO_open
 PerlIO *
-PerlIO_open(const char *path, const char *mode)
+PerlIO_push(PerlIO *f,PerlIO_funcs *tab,const char *mode,const char *arg,STRLEN len)
 {
- PerlIO *f = NULL;
- int oflags = PerlIO_oflags(mode);
- if (oflags != -1)
+ dTHX;
+ PerlIOl *l = NULL;
+ l = PerlMemShared_calloc(tab->size,sizeof(char));
+ if (l)
   {
-   int fd = open(path,oflags,0666);
-   if (fd >= 0)
+   Zero(l,tab->size,char);
+   l->next = *f;
+   l->tab  = tab;
+   *f      = l;
+   PerlIO_debug("PerlIO_push f=%p %s %s\n",f,tab->name,(mode) ? mode : "(Null)");
+   if ((*l->tab->Pushed)(f,mode,arg,len) != 0)
     {
-     PerlIO_debug(__FUNCTION__ "fd=%d\n",fd);
-     f = PerlIO_fdopen(fd,mode);
-     if (!f)
-      close(fd);
+     PerlIO_pop(f);
+     return NULL;
     }
   }
- PerlIO_debug(__FUNCTION__ " path=%s m=%s f=%p\n",path,mode,f);
  return f;
 }
 
-#undef PerlIO_reopen
-PerlIO *
-PerlIO_reopen(const char *path, const char *mode, PerlIO *f)
+int
+PerlIO_apply_layers(pTHX_ PerlIO *f, const char *mode, const char *names)
 {
- PerlIO_debug(__FUNCTION__ " n=%s m=%s f=%p\n",path,mode,f);
- if (f)
+ if (names)
   {
-   int oflags = PerlIO_oflags(mode);
-   PerlIO_close(f);
-   if (oflags != -1)
+   const char *s = names;
+   while (*s)
     {
-     int fd = open(path,oflags,0666);
-     if (fd >= 0)
+     while (isSPACE(*s))
+      s++;
+     if (*s == ':')
+      s++;
+     if (*s)
       {
-       PerlIO_debug(__FUNCTION__ "fd=%d\n",fd);
-       f->oflags = oflags;
-       f->flags  |= (PERLIO_F_OPEN|PERLIO_F_USED);
+       const char *e = s;
+       const char *as = Nullch;
+       const char *ae = Nullch;
+       int count = 0;
+       while (*e && *e != ':' && !isSPACE(*e))
+        {
+         if (*e == '(')
+          {
+           if (!as)
+            as = e;
+           count++;
+          }
+         else if (*e == ')')
+          {
+           if (as && --count == 0)
+            ae = e;
+          }
+         e++;
+        }
+       if (e > s)
+        {
+         if ((e - s) == 3 && strncmp(s,"raw",3) == 0)
+          {
+           /* Pop back to bottom layer */
+           if (PerlIONext(f))
+            {
+             PerlIO_flush(f);
+             while (PerlIONext(f))
+              {
+               PerlIO_pop(f);
+              }
+            }
+          }
+         else if ((e - s) == 4 && strncmp(s,"utf8",4) == 0)
+          {
+           PerlIOBase(f)->flags |= PERLIO_F_UTF8;
+          }
+         else if ((e - s) == 5 && strncmp(s,"bytes",5) == 0)
+          {
+           PerlIOBase(f)->flags &= ~PERLIO_F_UTF8;
+          }
+         else
+          {
+           STRLEN len = ((as) ? as : e)-s;
+           SV *layer = PerlIO_find_layer(s,len);
+           if (layer)
+            {
+             PerlIO_funcs *tab = INT2PTR(PerlIO_funcs *, SvIV(SvRV(layer)));
+             if (tab)
+              {
+               len = (as) ? (ae-(as++)-1) : 0;
+               if (!PerlIO_push(f,tab,mode,as,len))
+                return -1;
+              }
+            }
+           else
+            Perl_warn(aTHX_ "perlio: unknown layer \"%.*s\"",(int)len,s);
+          }
+        }
+       s = e;
       }
     }
-   else
-    {
-     return NULL;
-    }
   }
- return PerlIO_open(path,mode);
+ return 0;
 }
 
-void
-PerlIO_init(void)
+
+
+/*--------------------------------------------------------------------------------------*/
+/* Given the abstraction above the public API functions */
+
+int
+PerlIO_binmode(pTHX_ PerlIO *f, int iotype, int mode, const char *names)
 {
- if (!_perlio)
+ PerlIO_debug("PerlIO_binmode f=%p %s %c %x %s\n",
+              f,PerlIOBase(f)->tab->name,iotype,mode, (names) ? names : "(Null)");
+ if (!names && (O_TEXT != O_BINARY && (mode & O_BINARY)))
   {
-   atexit(&PerlIO_cleanup);
-   PerlIO_fdopen(0,"r");
-   PerlIO_fdopen(1,"w");
-   PerlIO_fdopen(2,"w");
+   PerlIO *top = f;
+   PerlIOl *l;
+   while (l = *top)
+    {
+     if (PerlIOBase(top)->tab == &PerlIO_crlf)
+      {
+       PerlIO_flush(top);
+       PerlIOBase(top)->flags &= ~PERLIO_F_CRLF;
+       break;
+      }
+     top = PerlIONext(top);
+    }
   }
- PerlIO_debug(__FUNCTION__ "\n");
+ return PerlIO_apply_layers(aTHX_ f, NULL, names) == 0 ? TRUE : FALSE;
 }
 
-#undef PerlIO_stdin
+#undef PerlIO__close
+int
+PerlIO__close(PerlIO *f)
+{
+ return (*PerlIOBase(f)->tab->Close)(f);
+}
+
+#undef PerlIO_fdupopen
 PerlIO *
-PerlIO_stdin(void)
+PerlIO_fdupopen(pTHX_ PerlIO *f)
 {
- if (!_perlio)
-  PerlIO_init();
- return _perlio[0];
+ char buf[8];
+ int fd = PerlLIO_dup(PerlIO_fileno(f));
+ PerlIO *new = PerlIO_fdopen(fd,PerlIO_modestr(f,buf));
+ if (new)
+  {
+   Off_t posn = PerlIO_tell(f);
+   PerlIO_seek(new,posn,SEEK_SET);
+  }
+ return new;
 }
 
-#undef PerlIO_stdout
+#undef PerlIO_close
+int
+PerlIO_close(PerlIO *f)
+{
+ int code = (*PerlIOBase(f)->tab->Close)(f);
+ while (*f)
+  {
+   PerlIO_pop(f);
+  }
+ return code;
+}
+
+#undef PerlIO_fileno
+int
+PerlIO_fileno(PerlIO *f)
+{
+ return (*PerlIOBase(f)->tab->Fileno)(f);
+}
+
+
+
+#undef PerlIO_fdopen
 PerlIO *
-PerlIO_stdout(void)
+PerlIO_fdopen(int fd, const char *mode)
 {
+ PerlIO_funcs *tab = PerlIO_default_top();
  if (!_perlio)
-  PerlIO_init();
- return _perlio[1];
+  PerlIO_stdstreams();
+ return (*tab->Fdopen)(tab,fd,mode);
 }
 
-#undef PerlIO_stderr
+#undef PerlIO_open
 PerlIO *
-PerlIO_stderr(void)
+PerlIO_open(const char *path, const char *mode)
 {
+ PerlIO_funcs *tab = PerlIO_default_top();
  if (!_perlio)
-  PerlIO_init();
- return _perlio[2];
+  PerlIO_stdstreams();
+ return (*tab->Open)(tab,path,mode);
+}
+
+#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)
+    {
+     if ((*PerlIOBase(f)->tab->Pushed)(f,mode,Nullch,0) == 0)
+      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_unread
+SSize_t
+PerlIO_unread(PerlIO *f, const void *vbuf, Size_t count)
+{
+ return (*PerlIOBase(f)->tab->Unread)(f,vbuf,count);
+}
+
+#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_fill
+int
+PerlIO_fill(PerlIO *f)
+{
+ return (*PerlIOBase(f)->tab->Fill)(f);
+}
+
+#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 (*PerlIOBase(f)->tab->Error)(f);
+}
+
+#undef PerlIO_clearerr
+void
+PerlIO_clearerr(PerlIO *f)
+{
+ if (f && *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
 PerlIO_fast_gets(PerlIO *f)
 {
- return 1;
+ if (f && *f && (PerlIOBase(f)->flags & PERLIO_F_FASTGETS))
+  {
+   PerlIO_funcs *tab = PerlIOBase(f)->tab;
+   return (tab->Set_ptrcnt != NULL);
+  }
+ return 0;
 }
 
 #undef PerlIO_has_cntptr
 int
 PerlIO_has_cntptr(PerlIO *f)
 {
- return 1;
+ if (f && *f)
+  {
+   PerlIO_funcs *tab = PerlIOBase(f)->tab;
+   return (tab->Get_ptr != NULL && tab->Get_cnt != NULL);
+  }
+ return 0;
 }
 
 #undef PerlIO_canset_cnt
 int
 PerlIO_canset_cnt(PerlIO *f)
 {
- return 1;
+ if (f && *f)
+  {
+   PerlIOl *l = PerlIOBase(f);
+   return (l->tab->Set_ptrcnt != NULL);
+  }
+ return 0;
+}
+
+#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)
+{
+ PerlIO_funcs *tab = PerlIOBase(f)->tab;
+ if (tab->Get_ptr == NULL)
+  return NULL;
+ return (*tab->Get_ptr)(f);
+}
+
+#undef PerlIO_get_cnt
+int
+PerlIO_get_cnt(PerlIO *f)
+{
+ PerlIO_funcs *tab = PerlIOBase(f)->tab;
+ if (tab->Get_cnt == NULL)
+  return 0;
+ return (*tab->Get_cnt)(f);
 }
 
 #undef PerlIO_set_cnt
 void
-PerlIO_set_cnt(PerlIO *f, int cnt)
+PerlIO_set_cnt(PerlIO *f,int cnt)
 {
- if (f)
+ (*PerlIOBase(f)->tab->Set_ptrcnt)(f,NULL,cnt);
+}
+
+#undef PerlIO_set_ptrcnt
+void
+PerlIO_set_ptrcnt(PerlIO *f, STDCHAR *ptr, int cnt)
+{
+ PerlIO_funcs *tab = PerlIOBase(f)->tab;
+ if (tab->Set_ptrcnt == NULL)
   {
    dTHX;
-   if (!f->buf)
-    PerlIO_alloc_buf(f);
-   f->ptr = f->end - cnt;
-   assert(f->ptr >= f->buf);
+   Perl_croak(aTHX_ "PerlIO buffer snooping abuse");
+  }
+ (*PerlIOBase(f)->tab->Set_ptrcnt)(f,ptr,cnt);
+}
+
+/*--------------------------------------------------------------------------------------*/
+/* "Methods" of the "base class" */
+
+IV
+PerlIOBase_fileno(PerlIO *f)
+{
+ return PerlIO_fileno(PerlIONext(f));
+}
+
+char *
+PerlIO_modestr(PerlIO *f,char *buf)
+{
+ char *s = buf;
+ IV flags = PerlIOBase(f)->flags;
+ if (flags & PERLIO_F_APPEND)
+  {
+   *s++ = 'a';
+   if (flags & PERLIO_F_CANREAD)
+    {
+     *s++ = '+';
+    }
+  }
+ else if (flags & PERLIO_F_CANREAD)
+  {
+   *s++ = 'r';
+   if (flags & PERLIO_F_CANWRITE)
+    *s++ = '+';
+  }
+ else if (flags & PERLIO_F_CANWRITE)
+  {
+   *s++ = 'w';
+   if (flags & PERLIO_F_CANREAD)
+    {
+     *s++ = '+';
+    }
+  }
+#if O_TEXT != O_BINARY
+ if (!(flags & PERLIO_F_CRLF))
+  *s++ = 'b';
+#endif
+ *s = '\0';
+ return buf;
+}
+
+IV
+PerlIOBase_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
+{
+ PerlIOl *l = PerlIOBase(f);
+ const char *omode = mode;
+ char temp[8];
+ PerlIO_funcs *tab = PerlIOBase(f)->tab;
+ l->flags  &= ~(PERLIO_F_CANREAD|PERLIO_F_CANWRITE|
+                PERLIO_F_TRUNCATE|PERLIO_F_APPEND);
+ if (tab->Set_ptrcnt != NULL)
+  l->flags |= PERLIO_F_FASTGETS;
+ 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_CRLF;
+        break;
+       case 't':
+        l->flags |= PERLIO_F_CRLF;
+        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);
+    }
+  }
+#if 0
+ PerlIO_debug("PerlIOBase_pushed f=%p %s %s fl=%08"UVxf" (%s)\n",
+              f,PerlIOBase(f)->tab->name,(omode) ? omode : "(Null)",
+              l->flags,PerlIO_modestr(f,temp));
+#endif
+ return 0;
+}
+
+IV
+PerlIOBase_popped(PerlIO *f)
+{
+ return 0;
+}
+
+SSize_t
+PerlIOBase_unread(PerlIO *f, const void *vbuf, Size_t count)
+{
+ Off_t old = PerlIO_tell(f);
+ SSize_t done;
+ PerlIO_push(f,&PerlIO_pending,"r",Nullch,0);
+ done = PerlIOBuf_unread(f,vbuf,count);
+ PerlIOSelf(f,PerlIOBuf)->posn = old - done;
+ return done;
+}
+
+IV
+PerlIOBase_noop_ok(PerlIO *f)
+{
+ return 0;
+}
+
+IV
+PerlIOBase_noop_fail(PerlIO *f)
+{
+ return -1;
+}
+
+IV
+PerlIOBase_close(PerlIO *f)
+{
+ IV code = 0;
+ PerlIO *n = PerlIONext(f);
+ if (PerlIO_flush(f) != 0)
+  code = -1;
+ if (n && (*PerlIOBase(n)->tab->Close)(n) != 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)
+  {
+   PerlIO *n = PerlIONext(f);
+   PerlIOBase(f)->flags &= ~(PERLIO_F_ERROR|PERLIO_F_EOF);
+   if (n)
+    PerlIO_clearerr(n);
+  }
+}
+
+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 == 'b')
+  {
+   oflags |=  O_BINARY;
+   oflags &= ~O_TEXT;
+   mode++;
+  }
+ else if (*mode == 't')
+  {
+   oflags |=  O_TEXT;
+   oflags &= ~O_BINARY;
+   mode++;
+  }
+ /* Always open in binary mode */
+ oflags |= O_BINARY;
+ if (*mode || oflags == -1)
+  {
+   errno = EINVAL;
+   oflags = -1;
+  }
+ return oflags;
+}
+
+IV
+PerlIOUnix_fileno(PerlIO *f)
+{
+ return PerlIOSelf(f,PerlIOUnix)->fd;
+}
+
+PerlIO *
+PerlIOUnix_fdopen(PerlIO_funcs *self, int fd,const char *mode)
+{
+ dTHX;
+ 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(aTHX),self,mode,Nullch,0),PerlIOUnix);
+     s->fd     = fd;
+     s->oflags = oflags;
+     PerlIOBase(f)->flags |= PERLIO_F_OPEN;
+    }
+  }
+ return f;
+}
+
+PerlIO *
+PerlIOUnix_open(PerlIO_funcs *self, const char *path,const char *mode)
+{
+ dTHX;
+ PerlIO *f = NULL;
+ int oflags = PerlIOUnix_oflags(mode);
+ if (oflags != -1)
+  {
+   int fd = PerlLIO_open3(path,oflags,0666);
+   if (fd >= 0)
+    {
+     PerlIOUnix *s = PerlIOSelf(PerlIO_push(f = PerlIO_allocate(aTHX),self,mode,Nullch,0),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)
+  {
+   dTHX;
+   int fd = PerlLIO_open3(path,oflags,0666);
+   if (fd >= 0)
+    {
+     s->fd = fd;
+     s->oflags = oflags;
+     PerlIOBase(f)->flags |= PERLIO_F_OPEN;
+     return 0;
+    }
+  }
+ return -1;
+}
+
+SSize_t
+PerlIOUnix_read(PerlIO *f, void *vbuf, Size_t count)
+{
+ dTHX;
+ int fd = PerlIOSelf(f,PerlIOUnix)->fd;
+ if (!(PerlIOBase(f)->flags & PERLIO_F_CANREAD))
+  return 0;
+ while (1)
+  {
+   SSize_t len = PerlLIO_read(fd,vbuf,count);
+   if (len >= 0 || errno != EINTR)
+    {
+     if (len < 0)
+      PerlIOBase(f)->flags |= PERLIO_F_ERROR;
+     else if (len == 0 && count != 0)
+      PerlIOBase(f)->flags |= PERLIO_F_EOF;
+     return len;
+    }
+  }
+}
+
+SSize_t
+PerlIOUnix_write(PerlIO *f, const void *vbuf, Size_t count)
+{
+ dTHX;
+ int fd = PerlIOSelf(f,PerlIOUnix)->fd;
+ while (1)
+  {
+   SSize_t len = PerlLIO_write(fd,vbuf,count);
+   if (len >= 0 || errno != EINTR)
+    {
+     if (len < 0)
+      PerlIOBase(f)->flags |= PERLIO_F_ERROR;
+     return len;
+    }
+  }
+}
+
+IV
+PerlIOUnix_seek(PerlIO *f, Off_t offset, int whence)
+{
+ dTHX;
+ Off_t new = PerlLIO_lseek(PerlIOSelf(f,PerlIOUnix)->fd,offset,whence);
+ PerlIOBase(f)->flags &= ~PERLIO_F_EOF;
+ return (new == (Off_t) -1) ? -1 : 0;
+}
+
+Off_t
+PerlIOUnix_tell(PerlIO *f)
+{
+ dTHX;
+ Off_t posn = PerlLIO_lseek(PerlIOSelf(f,PerlIOUnix)->fd,0,SEEK_CUR);
+ return PerlLIO_lseek(PerlIOSelf(f,PerlIOUnix)->fd,0,SEEK_CUR);
+}
+
+IV
+PerlIOUnix_close(PerlIO *f)
+{
+ dTHX;
+ int fd = PerlIOSelf(f,PerlIOUnix)->fd;
+ int code = 0;
+ while (PerlLIO_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),
+ PERLIO_K_RAW,
+ PerlIOUnix_fileno,
+ PerlIOUnix_fdopen,
+ PerlIOUnix_open,
+ PerlIOUnix_reopen,
+ PerlIOBase_pushed,
+ PerlIOBase_noop_ok,
+ PerlIOUnix_read,
+ PerlIOBase_unread,
+ PerlIOUnix_write,
+ PerlIOUnix_seek,
+ PerlIOUnix_tell,
+ PerlIOUnix_close,
+ PerlIOBase_noop_ok,   /* flush */
+ PerlIOBase_noop_fail, /* fill */
+ 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)
+{
+ dTHX;
+ return PerlSIO_fileno(PerlIOSelf(f,PerlIOStdio)->stdio);
+}
+
+char *
+PerlIOStdio_mode(const char *mode,char *tmode)
+{
+ char *ret = tmode;
+ while (*mode)
+  {
+   *tmode++ = *mode++;
+  }
+ if (O_BINARY != O_TEXT)
+  {
+   *tmode++ = 'b';
+  }
+ *tmode = '\0';
+ return ret;
+}
+
+PerlIO *
+PerlIOStdio_fdopen(PerlIO_funcs *self, int fd,const char *mode)
+{
+ dTHX;
+ PerlIO *f = NULL;
+ int init = 0;
+ char tmode[8];
+ if (*mode == 'I')
+  {
+   init = 1;
+   mode++;
+  }
+ if (fd >= 0)
+  {
+   FILE *stdio = NULL;
+   if (init)
+    {
+     switch(fd)
+      {
+       case 0:
+        stdio = PerlSIO_stdin;
+        break;
+       case 1:
+        stdio = PerlSIO_stdout;
+        break;
+       case 2:
+        stdio = PerlSIO_stderr;
+        break;
+      }
+    }
+   else
+    {
+     stdio = PerlSIO_fdopen(fd,mode = PerlIOStdio_mode(mode,tmode));
+    }
+   if (stdio)
+    {
+     PerlIOStdio *s = PerlIOSelf(PerlIO_push(f = PerlIO_allocate(aTHX),self,mode,Nullch,0),PerlIOStdio);
+     s->stdio  = stdio;
+    }
+  }
+ return f;
+}
+
+#undef PerlIO_importFILE
+PerlIO *
+PerlIO_importFILE(FILE *stdio, int fl)
+{
+ dTHX;
+ PerlIO *f = NULL;
+ if (stdio)
+  {
+   PerlIOStdio *s = PerlIOSelf(PerlIO_push(f = PerlIO_allocate(aTHX),&PerlIO_stdio,"r+",Nullch,0),PerlIOStdio);
+   s->stdio  = stdio;
+  }
+ return f;
+}
+
+PerlIO *
+PerlIOStdio_open(PerlIO_funcs *self, const char *path,const char *mode)
+{
+ dTHX;
+ PerlIO *f = NULL;
+ FILE *stdio = PerlSIO_fopen(path,mode);
+ if (stdio)
+  {
+   char tmode[8];
+   PerlIOStdio *s = PerlIOSelf(PerlIO_push(f = PerlIO_allocate(aTHX), self,
+                               (mode = PerlIOStdio_mode(mode,tmode)),Nullch,0),
+                               PerlIOStdio);
+   s->stdio  = stdio;
+  }
+ return f;
+}
+
+int
+PerlIOStdio_reopen(const char *path, const char *mode, PerlIO *f)
+{
+ dTHX;
+ PerlIOStdio *s = PerlIOSelf(f,PerlIOStdio);
+ char tmode[8];
+ FILE *stdio = PerlSIO_freopen(path,(mode = PerlIOStdio_mode(mode,tmode)),s->stdio);
+ if (!s->stdio)
+  return -1;
+ s->stdio = stdio;
+ return 0;
+}
+
+SSize_t
+PerlIOStdio_read(PerlIO *f, void *vbuf, Size_t count)
+{
+ dTHX;
+ 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 = PerlSIO_fgetc(s);
+   if (ch != EOF)
+    {
+     *buf = ch;
+     got = 1;
+    }
+  }
+ else
+  got = PerlSIO_fread(vbuf,1,count,s);
+ return got;
+}
+
+SSize_t
+PerlIOStdio_unread(PerlIO *f, const void *vbuf, Size_t count)
+{
+ dTHX;
+ FILE *s = PerlIOSelf(f,PerlIOStdio)->stdio;
+ STDCHAR *buf = ((STDCHAR *)vbuf)+count-1;
+ SSize_t unread = 0;
+ while (count > 0)
+  {
+   int ch = *buf-- & 0xff;
+   if (PerlSIO_ungetc(ch,s) != ch)
+    break;
+   unread++;
+   count--;
+  }
+ return unread;
+}
+
+SSize_t
+PerlIOStdio_write(PerlIO *f, const void *vbuf, Size_t count)
+{
+ dTHX;
+ return PerlSIO_fwrite(vbuf,1,count,PerlIOSelf(f,PerlIOStdio)->stdio);
+}
+
+IV
+PerlIOStdio_seek(PerlIO *f, Off_t offset, int whence)
+{
+ dTHX;
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return PerlSIO_fseek(stdio,offset,whence);
+}
+
+Off_t
+PerlIOStdio_tell(PerlIO *f)
+{
+ dTHX;
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return PerlSIO_ftell(stdio);
+}
+
+IV
+PerlIOStdio_close(PerlIO *f)
+{
+ dTHX;
+#ifdef HAS_SOCKET
+ int optval, optlen = sizeof(int);
+#endif
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return(
+#ifdef HAS_SOCKET
+   (getsockopt(PerlIO_fileno(f), SOL_SOCKET, SO_TYPE, (char *)&optval, &optlen) < 0) ?
+       PerlSIO_fclose(stdio) :
+       close(PerlIO_fileno(f))
+#else
+   PerlSIO_fclose(stdio)
+#endif
+     );
+
+}
+
+IV
+PerlIOStdio_flush(PerlIO *f)
+{
+ dTHX;
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ if (PerlIOBase(f)->flags & PERLIO_F_CANWRITE)
+  {
+   return PerlSIO_fflush(stdio);
+  }
+ else
+  {
+#if 0
+   /* FIXME: This discards ungetc() and pre-read stuff which is
+      not right if this is just a "sync" from a layer above
+      Suspect right design is to do _this_ but not have layer above
+      flush this layer read-to-read
+    */
+   /* Not writeable - sync by attempting a seek */
+   int err = errno;
+   if (PerlSIO_fseek(stdio,(Off_t) 0, SEEK_CUR) != 0)
+    errno = err;
+#endif
+  }
+ return 0;
+}
+
+IV
+PerlIOStdio_fill(PerlIO *f)
+{
+ dTHX;
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ int c;
+ /* fflush()ing read-only streams can cause trouble on some stdio-s */
+ if ((PerlIOBase(f)->flags & PERLIO_F_CANWRITE))
+  {
+   if (PerlSIO_fflush(stdio) != 0)
+    return EOF;
+  }
+ c = PerlSIO_fgetc(stdio);
+ if (c == EOF || PerlSIO_ungetc(c,stdio) != c)
+  return EOF;
+ return 0;
+}
+
+IV
+PerlIOStdio_eof(PerlIO *f)
+{
+ dTHX;
+ return PerlSIO_feof(PerlIOSelf(f,PerlIOStdio)->stdio);
+}
+
+IV
+PerlIOStdio_error(PerlIO *f)
+{
+ dTHX;
+ return PerlSIO_ferror(PerlIOSelf(f,PerlIOStdio)->stdio);
+}
+
+void
+PerlIOStdio_clearerr(PerlIO *f)
+{
+ dTHX;
+ PerlSIO_clearerr(PerlIOSelf(f,PerlIOStdio)->stdio);
+}
+
+void
+PerlIOStdio_setlinebuf(PerlIO *f)
+{
+ dTHX;
+#ifdef HAS_SETLINEBUF
+ PerlSIO_setlinebuf(PerlIOSelf(f,PerlIOStdio)->stdio);
+#else
+ PerlSIO_setvbuf(PerlIOSelf(f,PerlIOStdio)->stdio, Nullch, _IOLBF, 0);
+#endif
+}
+
+#ifdef FILE_base
+STDCHAR *
+PerlIOStdio_get_base(PerlIO *f)
+{
+ dTHX;
+ FILE *stdio  = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return PerlSIO_get_base(stdio);
+}
+
+Size_t
+PerlIOStdio_get_bufsiz(PerlIO *f)
+{
+ dTHX;
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return PerlSIO_get_bufsiz(stdio);
+}
+#endif
+
+#ifdef USE_STDIO_PTR
+STDCHAR *
+PerlIOStdio_get_ptr(PerlIO *f)
+{
+ dTHX;
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return PerlSIO_get_ptr(stdio);
+}
+
+SSize_t
+PerlIOStdio_get_cnt(PerlIO *f)
+{
+ dTHX;
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ return PerlSIO_get_cnt(stdio);
+}
+
+void
+PerlIOStdio_set_ptrcnt(PerlIO *f,STDCHAR *ptr,SSize_t cnt)
+{
+ dTHX;
+ FILE *stdio = PerlIOSelf(f,PerlIOStdio)->stdio;
+ if (ptr != NULL)
+  {
+#ifdef STDIO_PTR_LVALUE
+   PerlSIO_set_ptr(stdio,ptr);
+#ifdef STDIO_PTR_LVAL_SETS_CNT
+   if (PerlSIO_get_cnt(stdio) != (cnt))
+    {
+     dTHX;
+     assert(PerlSIO_get_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 */
+   PerlProc_abort();
+#endif /* STDIO_PTR_LVALUE */
+  }
+/* Now (or only) set cnt */
+#ifdef STDIO_CNT_LVALUE
+ PerlSIO_set_cnt(stdio,cnt);
+#else  /* STDIO_CNT_LVALUE */
+#if (defined(STDIO_PTR_LVALUE) && defined(STDIO_PTR_LVAL_SETS_CNT))
+ PerlSIO_set_ptr(stdio,PerlSIO_get_ptr(stdio)+(PerlSIO_get_cnt(stdio)-cnt));
+#else  /* STDIO_PTR_LVAL_SETS_CNT */
+ PerlProc_abort();
+#endif /* STDIO_PTR_LVAL_SETS_CNT */
+#endif /* STDIO_CNT_LVALUE */
+}
+
+#endif
+
+PerlIO_funcs PerlIO_stdio = {
+ "stdio",
+ sizeof(PerlIOStdio),
+ PERLIO_K_BUFFERED,
+ PerlIOStdio_fileno,
+ PerlIOStdio_fdopen,
+ PerlIOStdio_open,
+ PerlIOStdio_reopen,
+ PerlIOBase_pushed,
+ PerlIOBase_noop_ok,
+ PerlIOStdio_read,
+ PerlIOStdio_unread,
+ PerlIOStdio_write,
+ PerlIOStdio_seek,
+ PerlIOStdio_tell,
+ PerlIOStdio_close,
+ PerlIOStdio_flush,
+ PerlIOStdio_fill,
+ PerlIOStdio_eof,
+ PerlIOStdio_error,
+ PerlIOStdio_clearerr,
+ PerlIOStdio_setlinebuf,
+#ifdef FILE_base
+ PerlIOStdio_get_base,
+ PerlIOStdio_get_bufsiz,
+#else
+ 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 */
+
+IV
+PerlIOBuf_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ b->posn = PerlIO_tell(PerlIONext(f));
+ return PerlIOBase_pushed(f,mode,arg,len);
+}
+
+PerlIO *
+PerlIOBuf_fdopen(PerlIO_funcs *self, int fd, const char *mode)
+{
+ dTHX;
+ PerlIO_funcs *tab = PerlIO_default_btm();
+ int init = 0;
+ PerlIO *f;
+ if (*mode == 'I')
+  {
+   init = 1;
+   mode++;
+  }
+#if O_BINARY != O_TEXT
+ /* do something about failing setmode()? --jhi */
+ PerlLIO_setmode(fd, O_BINARY);
+#endif
+ f = (*tab->Fdopen)(tab,fd,mode);
+ if (f)
+  {
+   PerlIOBuf *b = PerlIOSelf(PerlIO_push(f,self,mode,Nullch,0),PerlIOBuf);
+   if (init && fd == 2)
+    {
+     /* Initial stderr is unbuffered */
+     PerlIOBase(f)->flags |= PERLIO_F_UNBUF;
+    }
+#if 0
+   PerlIO_debug("PerlIOBuf_fdopen %s f=%p fd=%d m=%s fl=%08"UVxf"\n",
+                self->name,f,fd,mode,PerlIOBase(f)->flags);
+#endif
+  }
+ return f;
+}
+
+PerlIO *
+PerlIOBuf_open(PerlIO_funcs *self, const char *path, const char *mode)
+{
+ PerlIO_funcs *tab = PerlIO_default_btm();
+ PerlIO *f = (*tab->Open)(tab,path,mode);
+ if (f)
+  {
+   PerlIO_push(f,self,mode,Nullch,0);
+  }
+ return f;
+}
+
+int
+PerlIOBuf_reopen(const char *path, const char *mode, PerlIO *f)
+{
+ PerlIO *next = PerlIONext(f);
+ int code = (*PerlIOBase(next)->tab->Reopen)(path,mode,next);
+ if (code = 0)
+  code = (*PerlIOBase(f)->tab->Pushed)(f,mode,Nullch,0);
+ return code;
+}
+
+/* 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 *buf = b->buf;
+   STDCHAR *p = buf;
+   int count;
+   PerlIO *n = PerlIONext(f);
+   while (p < b->ptr)
+    {
+     count = PerlIO_write(n,p,b->ptr - p);
+     if (count > 0)
+      {
+       p += count;
+      }
+     else if (count < 0 || PerlIO_error(n))
+      {
+       PerlIOBase(f)->flags |= PERLIO_F_ERROR;
+       code = -1;
+       break;
+      }
+    }
+   b->posn += (p - buf);
+  }
+ else if (PerlIOBase(f)->flags & PERLIO_F_RDBUF)
+  {
+   STDCHAR *buf = PerlIO_get_base(f);
+   /* Note position change */
+   b->posn += (b->ptr - 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);
+ /* FIXME: Is this right for read case ? */
+ if (PerlIO_flush(PerlIONext(f)) != 0)
+  code = -1;
+ return code;
+}
+
+IV
+PerlIOBuf_fill(PerlIO *f)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ PerlIO *n = PerlIONext(f);
+ SSize_t avail;
+ /* FIXME: doing the down-stream flush is a bad idea if it causes
+    pre-read data in stdio buffer to be discarded
+    but this is too simplistic - as it skips _our_ hosekeeping
+    and breaks tell tests.
+ if (!(PerlIOBase(f)->flags & PERLIO_F_RDBUF))
+  {
+  }
+  */
+ if (PerlIO_flush(f) != 0)
+  return -1;
+
+ if (!b->buf)
+  PerlIO_get_base(f); /* allocate via vtable */
+
+ b->ptr = b->end = b->buf;
+ if (PerlIO_fast_gets(n))
+  {
+   /* Layer below is also buffered
+    * We do _NOT_ want to call its ->Read() because that will loop
+    * till it gets what we asked for which may hang on a pipe etc.
+    * Instead take anything it has to hand, or ask it to fill _once_.
+    */
+   avail  = PerlIO_get_cnt(n);
+   if (avail <= 0)
+    {
+     avail = PerlIO_fill(n);
+     if (avail == 0)
+      avail = PerlIO_get_cnt(n);
+     else
+      {
+       if (!PerlIO_error(n) && PerlIO_eof(n))
+        avail = 0;
+      }
+    }
+   if (avail > 0)
+    {
+     STDCHAR *ptr = PerlIO_get_ptr(n);
+     SSize_t cnt  = avail;
+     if (avail > b->bufsiz)
+      avail = b->bufsiz;
+     Copy(ptr,b->buf,avail,STDCHAR);
+     PerlIO_set_ptrcnt(n,ptr+avail,cnt-avail);
+    }
+  }
+ else
+  {
+   avail = PerlIO_read(n,b->ptr,b->bufsiz);
+  }
+ if (avail <= 0)
+  {
+   if (avail == 0)
+    PerlIOBase(f)->flags |= PERLIO_F_EOF;
+   else
+    PerlIOBase(f)->flags |= PERLIO_F_ERROR;
+   return -1;
+  }
+ b->end      = b->buf+avail;
+ PerlIOBase(f)->flags |= PERLIO_F_RDBUF;
+ return 0;
+}
+
+SSize_t
+PerlIOBuf_read(PerlIO *f, void *vbuf, Size_t count)
+{
+ PerlIOBuf *b  = PerlIOSelf(f,PerlIOBuf);
+ STDCHAR *buf  = (STDCHAR *) vbuf;
+ if (f)
+  {
+   if (!b->ptr)
+    PerlIO_get_base(f);
+   if (!(PerlIOBase(f)->flags & PERLIO_F_CANREAD))
+    return 0;
+   while (count > 0)
+    {
+     SSize_t avail = PerlIO_get_cnt(f);
+     SSize_t take  = (count < avail) ? count : avail;
+     if (take > 0)
+      {
+       STDCHAR *ptr = PerlIO_get_ptr(f);
+       Copy(ptr,buf,take,STDCHAR);
+       PerlIO_set_ptrcnt(f,ptr+take,(avail -= take));
+       count   -= take;
+       buf     += take;
+      }
+     if (count > 0  && avail <= 0)
+      {
+       if (PerlIO_fill(f) != 0)
+        break;
+      }
+    }
+   return (buf - (STDCHAR *) vbuf);
+  }
+ return 0;
+}
+
+SSize_t
+PerlIOBuf_unread(PerlIO *f, const void *vbuf, Size_t count)
+{
+ const STDCHAR *buf = (const STDCHAR *) vbuf+count;
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ SSize_t unread = 0;
+ SSize_t avail;
+ if (PerlIOBase(f)->flags & PERLIO_F_WRBUF)
+  PerlIO_flush(f);
+ if (!b->buf)
+  PerlIO_get_base(f);
+ if (b->buf)
+  {
+   if (PerlIOBase(f)->flags & PERLIO_F_RDBUF)
+    {
+     avail = (b->ptr - b->buf);
+    }
+   else
+    {
+     avail = b->bufsiz;
+     b->end = b->buf + avail;
+     b->ptr = b->end;
+     PerlIOBase(f)->flags |= PERLIO_F_RDBUF;
+     b->posn -= b->bufsiz;
+    }
+   if (avail > (SSize_t) count)
+    avail = count;
+   if (avail > 0)
+    {
+     b->ptr -= avail;
+     buf    -= avail;
+     if (buf != b->ptr)
+      {
+       Copy(buf,b->ptr,avail,STDCHAR);
+      }
+     count  -= avail;
+     unread += avail;
+     PerlIOBase(f)->flags &= ~ PERLIO_F_EOF;
+    }
+  }
+ return unread;
+}
+
+SSize_t
+PerlIOBuf_write(PerlIO *f, const void *vbuf, Size_t count)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ const STDCHAR *buf = (const STDCHAR *) vbuf;
+ Size_t written = 0;
+ if (!b->buf)
+  PerlIO_get_base(f);
+ 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,STDCHAR);
+       count   -= avail;
+       buf     += avail;
+       written += avail;
+       b->ptr  += avail;
+      }
+    }
+   if (b->ptr >= (b->buf + b->bufsiz))
+    PerlIO_flush(f);
+  }
+ if (PerlIOBase(f)->flags & PERLIO_F_UNBUF)
+  PerlIO_flush(f);
+ return written;
+}
+
+IV
+PerlIOBuf_seek(PerlIO *f, Off_t offset, int whence)
+{
+ IV code;
+ if ((code = PerlIO_flush(f)) == 0)
+  {
+   PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+   PerlIOBase(f)->flags &= ~PERLIO_F_EOF;
+   code = PerlIO_seek(PerlIONext(f),offset,whence);
+   if (code == 0)
+    {
+     b->posn = PerlIO_tell(PerlIONext(f));
+    }
+  }
+ return code;
+}
+
+Off_t
+PerlIOBuf_tell(PerlIO *f)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ Off_t posn = b->posn;
+ if (b->buf)
+  posn += (b->ptr - b->buf);
+ return posn;
+}
+
+IV
+PerlIOBuf_close(PerlIO *f)
+{
+ dTHX;
+ IV code = PerlIOBase_close(f);
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (b->buf && b->buf != (STDCHAR *) &b->oneword)
+  {
+   PerlMemShared_free(b->buf);
+  }
+ b->buf = NULL;
+ b->ptr = b->end = b->buf;
+ PerlIOBase(f)->flags &= ~(PERLIO_F_RDBUF|PERLIO_F_WRBUF);
+ return code;
+}
+
+void
+PerlIOBuf_setlinebuf(PerlIO *f)
+{
+ if (f)
+  {
+   PerlIOBase(f)->flags &= ~PERLIO_F_LINEBUF;
+  }
+}
+
+STDCHAR *
+PerlIOBuf_get_ptr(PerlIO *f)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (!b->buf)
+  PerlIO_get_base(f);
+ return b->ptr;
+}
+
+SSize_t
+PerlIOBuf_get_cnt(PerlIO *f)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (!b->buf)
+  PerlIO_get_base(f);
+ 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)
+  {
+   dTHX;
+   if (!b->bufsiz)
+    b->bufsiz = 4096;
+   b->buf = PerlMemShared_calloc(b->bufsiz,sizeof(STDCHAR));
+   if (!b->buf)
+    {
+     b->buf = (STDCHAR *)&b->oneword;
+     b->bufsiz = sizeof(b->oneword);
+    }
+   b->ptr = b->buf;
+   b->end = b->ptr;
+  }
+ return b->buf;
+}
+
+Size_t
+PerlIOBuf_bufsiz(PerlIO *f)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (!b->buf)
+  PerlIO_get_base(f);
+ return (b->end - b->buf);
+}
+
+void
+PerlIOBuf_set_ptrcnt(PerlIO *f, STDCHAR *ptr, SSize_t cnt)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (!b->buf)
+  PerlIO_get_base(f);
+ 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;
+}
+
+PerlIO_funcs PerlIO_perlio = {
+ "perlio",
+ sizeof(PerlIOBuf),
+ PERLIO_K_BUFFERED,
+ PerlIOBase_fileno,
+ PerlIOBuf_fdopen,
+ PerlIOBuf_open,
+ PerlIOBuf_reopen,
+ PerlIOBuf_pushed,
+ PerlIOBase_noop_ok,
+ PerlIOBuf_read,
+ PerlIOBuf_unread,
+ PerlIOBuf_write,
+ PerlIOBuf_seek,
+ PerlIOBuf_tell,
+ PerlIOBuf_close,
+ PerlIOBuf_flush,
+ PerlIOBuf_fill,
+ PerlIOBase_eof,
+ PerlIOBase_error,
+ PerlIOBase_clearerr,
+ PerlIOBuf_setlinebuf,
+ PerlIOBuf_get_base,
+ PerlIOBuf_bufsiz,
+ PerlIOBuf_get_ptr,
+ PerlIOBuf_get_cnt,
+ PerlIOBuf_set_ptrcnt,
+};
+
+/*--------------------------------------------------------------------------------------*/
+/* Temp layer to hold unread chars when cannot do it any other way */
+
+IV
+PerlIOPending_fill(PerlIO *f)
+{
+ /* Should never happen */
+ PerlIO_flush(f);
+ return 0;
+}
+
+IV
+PerlIOPending_close(PerlIO *f)
+{
+ /* A tad tricky - flush pops us, then we close new top */
+ PerlIO_flush(f);
+ return PerlIO_close(f);
+}
+
+IV
+PerlIOPending_seek(PerlIO *f, Off_t offset, int whence)
+{
+ /* A tad tricky - flush pops us, then we seek new top */
+ PerlIO_flush(f);
+ return PerlIO_seek(f,offset,whence);
+}
+
+
+IV
+PerlIOPending_flush(PerlIO *f)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (b->buf && b->buf != (STDCHAR *) &b->oneword)
+  {
+   dTHX;
+   PerlMemShared_free(b->buf);
+   b->buf = NULL;
+  }
+ PerlIO_pop(f);
+ return 0;
+}
+
+void
+PerlIOPending_set_ptrcnt(PerlIO *f, STDCHAR *ptr, SSize_t cnt)
+{
+ if (cnt <= 0)
+  {
+   PerlIO_flush(f);
+  }
+ else
+  {
+   PerlIOBuf_set_ptrcnt(f,ptr,cnt);
+  }
+}
+
+IV
+PerlIOPending_pushed(PerlIO *f,const char *mode,const char *arg,STRLEN len)
+{
+ IV code    = PerlIOBase_pushed(f,mode,arg,len);
+ PerlIOl *l = PerlIOBase(f);
+ /* Our PerlIO_fast_gets must match what we are pushed on,
+    or sv_gets() etc. get muddled when it changes mid-string
+    when we auto-pop.
+  */
+ l->flags   = (l->flags & ~(PERLIO_F_FASTGETS|PERLIO_F_UTF8)) |
+              (PerlIOBase(PerlIONext(f))->flags & (PERLIO_F_FASTGETS|PERLIO_F_UTF8));
+ return code;
+}
+
+SSize_t
+PerlIOPending_read(PerlIO *f, void *vbuf, Size_t count)
+{
+ SSize_t avail = PerlIO_get_cnt(f);
+ SSize_t got   = 0;
+ if (count < avail)
+  avail = count;
+ if (avail > 0)
+  got = PerlIOBuf_read(f,vbuf,avail);
+ if (got < count)
+  got += PerlIO_read(f,((STDCHAR *) vbuf)+got,count-got);
+ return got;
+}
+
+
+PerlIO_funcs PerlIO_pending = {
+ "pending",
+ sizeof(PerlIOBuf),
+ PERLIO_K_BUFFERED,
+ PerlIOBase_fileno,
+ NULL,
+ NULL,
+ NULL,
+ PerlIOPending_pushed,
+ PerlIOBase_noop_ok,
+ PerlIOPending_read,
+ PerlIOBuf_unread,
+ PerlIOBuf_write,
+ PerlIOPending_seek,
+ PerlIOBuf_tell,
+ PerlIOPending_close,
+ PerlIOPending_flush,
+ PerlIOPending_fill,
+ PerlIOBase_eof,
+ PerlIOBase_error,
+ PerlIOBase_clearerr,
+ PerlIOBuf_setlinebuf,
+ PerlIOBuf_get_base,
+ PerlIOBuf_bufsiz,
+ PerlIOBuf_get_ptr,
+ PerlIOBuf_get_cnt,
+ PerlIOPending_set_ptrcnt,
+};
+
+
+
+/*--------------------------------------------------------------------------------------*/
+/* crlf - translation
+   On read translate CR,LF to "\n" we do this by overriding ptr/cnt entries
+   to hand back a line at a time and keeping a record of which nl we "lied" about.
+   On write translate "\n" to CR,LF
+ */
+
+typedef struct
+{
+ PerlIOBuf	base;         /* PerlIOBuf stuff */
+ STDCHAR       *nl;           /* Position of crlf we "lied" about in the buffer */
+} PerlIOCrlf;
+
+IV
+PerlIOCrlf_pushed(PerlIO *f, const char *mode,const char *arg,STRLEN len)
+{
+ IV code;
+ PerlIOBase(f)->flags |= PERLIO_F_CRLF;
+ code = PerlIOBuf_pushed(f,mode,arg,len);
+#if 0
+ PerlIO_debug("PerlIOCrlf_pushed f=%p %s %s fl=%08"UVxf"\n",
+              f,PerlIOBase(f)->tab->name,(mode) ? mode : "(Null)",
+              PerlIOBase(f)->flags);
+#endif
+ return code;
+}
+
+
+SSize_t
+PerlIOCrlf_unread(PerlIO *f, const void *vbuf, Size_t count)
+{
+ PerlIOCrlf *c = PerlIOSelf(f,PerlIOCrlf);
+ if (c->nl)
+  {
+   *(c->nl) = 0xd;
+   c->nl = NULL;
+  }
+ if (!(PerlIOBase(f)->flags & PERLIO_F_CRLF))
+  return PerlIOBuf_unread(f,vbuf,count);
+ else
+  {
+   const STDCHAR *buf = (const STDCHAR *) vbuf+count;
+   PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+   SSize_t unread = 0;
+   if (PerlIOBase(f)->flags & PERLIO_F_WRBUF)
+    PerlIO_flush(f);
+   if (!b->buf)
+    PerlIO_get_base(f);
+   if (b->buf)
+    {
+     if (!(PerlIOBase(f)->flags & PERLIO_F_RDBUF))
+      {
+       b->end = b->ptr = b->buf + b->bufsiz;
+       PerlIOBase(f)->flags |= PERLIO_F_RDBUF;
+       b->posn -= b->bufsiz;
+      }
+     while (count > 0 && b->ptr > b->buf)
+      {
+       int ch = *--buf;
+       if (ch == '\n')
+        {
+         if (b->ptr - 2 >= b->buf)
+          {
+           *--(b->ptr) = 0xa;
+           *--(b->ptr) = 0xd;
+           unread++;
+           count--;
+          }
+         else
+          {
+           buf++;
+           break;
+          }
+        }
+       else
+        {
+         *--(b->ptr) = ch;
+         unread++;
+         count--;
+        }
+      }
+    }
+   return unread;
+  }
+}
+
+SSize_t
+PerlIOCrlf_get_cnt(PerlIO *f)
+{
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ if (!b->buf)
+  PerlIO_get_base(f);
+ if (PerlIOBase(f)->flags & PERLIO_F_RDBUF)
+  {
+   PerlIOCrlf *c = PerlIOSelf(f,PerlIOCrlf);
+   if ((PerlIOBase(f)->flags & PERLIO_F_CRLF) && !c->nl)
+    {
+     STDCHAR *nl   = b->ptr;
+    scan:
+     while (nl < b->end && *nl != 0xd)
+      nl++;
+     if (nl < b->end && *nl == 0xd)
+      {
+     test:
+       if (nl+1 < b->end)
+        {
+         if (nl[1] == 0xa)
+          {
+           *nl   = '\n';
+           c->nl = nl;
+          }
+         else
+          {
+           /* Not CR,LF but just CR */
+           nl++;
+           goto scan;
+          }
+        }
+       else
+        {
+         /* Blast - found CR as last char in buffer */
+         if (b->ptr < nl)
+          {
+           /* They may not care, defer work as long as possible */
+           return (nl - b->ptr);
+          }
+         else
+          {
+           int code;
+           dTHX;
+           b->ptr++;               /* say we have read it as far as flush() is concerned */
+           b->buf++;               /* Leave space an front of buffer */
+           b->bufsiz--;            /* Buffer is thus smaller */
+           code = PerlIO_fill(f);  /* Fetch some more */
+           b->bufsiz++;            /* Restore size for next time */
+           b->buf--;               /* Point at space */
+           b->ptr = nl = b->buf;   /* Which is what we hand off */
+           b->posn--;              /* Buffer starts here */
+           *nl = 0xd;              /* Fill in the CR */
+           if (code == 0)
+            goto test;             /* fill() call worked */
+           /* CR at EOF - just fall through */
+          }
+        }
+      }
+    }
+   return (((c->nl) ? (c->nl+1) : b->end) - b->ptr);
+  }
+ return 0;
+}
+
+void
+PerlIOCrlf_set_ptrcnt(PerlIO *f, STDCHAR *ptr, SSize_t cnt)
+{
+ PerlIOBuf *b  = PerlIOSelf(f,PerlIOBuf);
+ PerlIOCrlf *c = PerlIOSelf(f,PerlIOCrlf);
+ IV flags = PerlIOBase(f)->flags;
+ if (!b->buf)
+  PerlIO_get_base(f);
+ if (!ptr)
+  {
+   if (c->nl)
+    ptr = c->nl+1;
+   else
+    {
+     ptr = b->end;
+     if ((flags & PERLIO_F_CRLF) && ptr > b->buf && ptr[-1] == 0xd)
+      ptr--;
+    }
+   ptr -= cnt;
+  }
+ else
+  {
+   /* Test code - delete when it works ... */
+   STDCHAR *chk;
+   if (c->nl)
+    chk = c->nl+1;
+   else
+    {
+     chk = b->end;
+     if ((flags & PERLIO_F_CRLF) && chk > b->buf && chk[-1] == 0xd)
+      chk--;
+    }
+   chk -= cnt;
+
+   if (ptr != chk)
+    {
+     dTHX;
+     Perl_croak(aTHX_ "ptr wrong %p != %p fl=%08"UVxf" nl=%p e=%p for %d",
+                ptr, chk, flags, c->nl, b->end, cnt);
+    }
+  }
+ if (c->nl)
+  {
+   if (ptr > c->nl)
+    {
+     /* They have taken what we lied about */
+     *(c->nl) = 0xd;
+     c->nl = NULL;
+     ptr++;
+    }
+  }
+ b->ptr = ptr;
+ PerlIOBase(f)->flags |= PERLIO_F_RDBUF;
+}
+
+SSize_t
+PerlIOCrlf_write(PerlIO *f, const void *vbuf, Size_t count)
+{
+ if (!(PerlIOBase(f)->flags & PERLIO_F_CRLF))
+  return PerlIOBuf_write(f,vbuf,count);
+ else
+  {
+   PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+   const STDCHAR *buf  = (const STDCHAR *) vbuf;
+   const STDCHAR *ebuf = buf+count;
+   if (!b->buf)
+    PerlIO_get_base(f);
+   if (!(PerlIOBase(f)->flags & PERLIO_F_CANWRITE))
+    return 0;
+   while (buf < ebuf)
+    {
+     STDCHAR *eptr = b->buf+b->bufsiz;
+     PerlIOBase(f)->flags |= PERLIO_F_WRBUF;
+     while (buf < ebuf && b->ptr < eptr)
+      {
+       if (*buf == '\n')
+        {
+         if ((b->ptr + 2) > eptr)
+          {
+           /* Not room for both */
+           PerlIO_flush(f);
+           break;
+          }
+         else
+          {
+           *(b->ptr)++ = 0xd; /* CR */
+           *(b->ptr)++ = 0xa; /* LF */
+           buf++;
+           if (PerlIOBase(f)->flags & PERLIO_F_LINEBUF)
+            {
+             PerlIO_flush(f);
+             break;
+            }
+          }
+        }
+       else
+        {
+         int ch = *buf++;
+         *(b->ptr)++ = ch;
+        }
+       if (b->ptr >= eptr)
+        {
+         PerlIO_flush(f);
+         break;
+        }
+      }
+    }
+   if (PerlIOBase(f)->flags & PERLIO_F_UNBUF)
+    PerlIO_flush(f);
+   return (buf - (STDCHAR *) vbuf);
+  }
+}
+
+IV
+PerlIOCrlf_flush(PerlIO *f)
+{
+ PerlIOCrlf *c = PerlIOSelf(f,PerlIOCrlf);
+ if (c->nl)
+  {
+   *(c->nl) = 0xd;
+   c->nl = NULL;
+  }
+ return PerlIOBuf_flush(f);
+}
+
+PerlIO_funcs PerlIO_crlf = {
+ "crlf",
+ sizeof(PerlIOCrlf),
+ PERLIO_K_BUFFERED|PERLIO_K_CANCRLF,
+ PerlIOBase_fileno,
+ PerlIOBuf_fdopen,
+ PerlIOBuf_open,
+ PerlIOBuf_reopen,
+ PerlIOCrlf_pushed,
+ PerlIOBase_noop_ok,   /* popped */
+ PerlIOBuf_read,       /* generic read works with ptr/cnt lies ... */
+ PerlIOCrlf_unread,    /* Put CR,LF in buffer for each '\n' */
+ PerlIOCrlf_write,     /* Put CR,LF in buffer for each '\n' */
+ PerlIOBuf_seek,
+ PerlIOBuf_tell,
+ PerlIOBuf_close,
+ PerlIOCrlf_flush,
+ PerlIOBuf_fill,
+ PerlIOBase_eof,
+ PerlIOBase_error,
+ PerlIOBase_clearerr,
+ PerlIOBuf_setlinebuf,
+ PerlIOBuf_get_base,
+ PerlIOBuf_bufsiz,
+ PerlIOBuf_get_ptr,
+ PerlIOCrlf_get_cnt,
+ PerlIOCrlf_set_ptrcnt,
+};
+
+#ifdef HAS_MMAP
+/*--------------------------------------------------------------------------------------*/
+/* mmap as "buffer" layer */
+
+typedef struct
+{
+ PerlIOBuf	base;         /* PerlIOBuf stuff */
+ Mmap_t		mptr;        /* Mapped address */
+ Size_t		len;          /* mapped length */
+ STDCHAR	*bbuf;        /* malloced buffer if map fails */
+} PerlIOMmap;
+
+static size_t page_size = 0;
+
+IV
+PerlIOMmap_map(PerlIO *f)
+{
+ dTHX;
+ PerlIOMmap *m = PerlIOSelf(f,PerlIOMmap);
+ PerlIOBuf  *b = &m->base;
+ IV flags = PerlIOBase(f)->flags;
+ IV code  = 0;
+ if (m->len)
+  abort();
+ if (flags & PERLIO_F_CANREAD)
+  {
+   PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+   int fd   = PerlIO_fileno(f);
+   struct stat st;
+   code = fstat(fd,&st);
+   if (code == 0 && S_ISREG(st.st_mode))
+    {
+     SSize_t len = st.st_size - b->posn;
+     if (len > 0)
+      {
+       Off_t posn;
+       if (!page_size) {
+#if defined(HAS_SYSCONF) && (defined(_SC_PAGESIZE) || defined(_SC_PAGE_SIZE))
+	   {
+	       SETERRNO(0,SS$_NORMAL);
+#   ifdef _SC_PAGESIZE
+	       page_size = sysconf(_SC_PAGESIZE);
+#   else
+	       page_size = sysconf(_SC_PAGE_SIZE);
+#   endif
+	       if ((long)page_size < 0) {
+		   if (errno) {
+		       SV *error = ERRSV;
+		       char *msg;
+		       STRLEN n_a;
+		       (void)SvUPGRADE(error, SVt_PV);
+		       msg = SvPVx(error, n_a);
+		       Perl_croak(aTHX_ "panic: sysconf: %s", msg);
+		   }
+		   else
+		       Perl_croak(aTHX_ "panic: sysconf: pagesize unknown");
+	       }
+	   }
+#else
+#   ifdef HAS_GETPAGESIZE
+        page_size = getpagesize();
+#   else
+#       if defined(I_SYS_PARAM) && defined(PAGESIZE)
+        page_size = PAGESIZE; /* compiletime, bad */
+#       endif
+#   endif
+#endif
+	if ((IV)page_size <= 0)
+	    Perl_croak(aTHX_ "panic: bad pagesize %"IVdf, (IV)page_size);
+       }
+       if (b->posn < 0)
+        {
+         /* This is a hack - should never happen - open should have set it ! */
+         b->posn = PerlIO_tell(PerlIONext(f));
+        }
+       posn = (b->posn / page_size) * page_size;
+       len  = st.st_size - posn;
+       m->mptr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, posn);
+       if (m->mptr && m->mptr != (Mmap_t) -1)
+        {
+#if 0 && defined(HAS_MADVISE) && defined(MADV_SEQUENTIAL)
+         madvise(m->mptr, len, MADV_SEQUENTIAL);
+#endif
+#if 0 && defined(HAS_MADVISE) && defined(MADV_WILLNEED)
+         madvise(m->mptr, len, MADV_WILLNEED);
+#endif
+         PerlIOBase(f)->flags = (flags & ~PERLIO_F_EOF) | PERLIO_F_RDBUF;
+         b->end  = ((STDCHAR *)m->mptr) + len;
+         b->buf  = ((STDCHAR *)m->mptr) + (b->posn - posn);
+         b->ptr  = b->buf;
+         m->len  = len;
+        }
+       else
+        {
+         b->buf = NULL;
+        }
+      }
+     else
+      {
+       PerlIOBase(f)->flags = flags | PERLIO_F_EOF | PERLIO_F_RDBUF;
+       b->buf = NULL;
+       b->ptr = b->end = b->ptr;
+       code = -1;
+      }
+    }
+  }
+ return code;
+}
+
+IV
+PerlIOMmap_unmap(PerlIO *f)
+{
+ PerlIOMmap *m = PerlIOSelf(f,PerlIOMmap);
+ PerlIOBuf  *b = &m->base;
+ IV code = 0;
+ if (m->len)
+  {
+   if (b->buf)
+    {
+     code = munmap(m->mptr, m->len);
+     b->buf  = NULL;
+     m->len  = 0;
+     m->mptr = NULL;
+     if (PerlIO_seek(PerlIONext(f),b->posn,SEEK_SET) != 0)
+      code = -1;
+    }
+   b->ptr = b->end = b->buf;
+   PerlIOBase(f)->flags &= ~(PERLIO_F_RDBUF|PERLIO_F_WRBUF);
+  }
+ return code;
+}
+
+STDCHAR *
+PerlIOMmap_get_base(PerlIO *f)
+{
+ PerlIOMmap *m = PerlIOSelf(f,PerlIOMmap);
+ PerlIOBuf  *b = &m->base;
+ if (b->buf && (PerlIOBase(f)->flags & PERLIO_F_RDBUF))
+  {
+   /* Already have a readbuffer in progress */
+   return b->buf;
+  }
+ if (b->buf)
+  {
+   /* We have a write buffer or flushed PerlIOBuf read buffer */
+   m->bbuf = b->buf;  /* save it in case we need it again */
+   b->buf  = NULL;    /* Clear to trigger below */
+  }
+ if (!b->buf)
+  {
+   PerlIOMmap_map(f);     /* Try and map it */
+   if (!b->buf)
+    {
+     /* Map did not work - recover PerlIOBuf buffer if we have one */
+     b->buf = m->bbuf;
+    }
   }
+ b->ptr  = b->end = b->buf;
+ if (b->buf)
+  return b->buf;
+ return PerlIOBuf_get_base(f);
 }
 
-#undef PerlIO_get_cnt
-int
-PerlIO_get_cnt(PerlIO *f)
+SSize_t
+PerlIOMmap_unread(PerlIO *f, const void *vbuf, Size_t count)
 {
- if (f)
+ PerlIOMmap *m = PerlIOSelf(f,PerlIOMmap);
+ PerlIOBuf  *b = &m->base;
+ if (PerlIOBase(f)->flags & PERLIO_F_WRBUF)
+  PerlIO_flush(f);
+ if (b->ptr && (b->ptr - count) >= b->buf && memEQ(b->ptr - count,vbuf,count))
   {
-   if (!f->buf)
-    PerlIO_alloc_buf(f);
-   if (f->flags & PERLIO_F_RDBUF)
-    return (f->end - f->ptr);
+   b->ptr -= count;
+   PerlIOBase(f)->flags &= ~ PERLIO_F_EOF;
+   return count;
   }
- return 0;
+ if (m->len)
+  {
+   /* Loose the unwritable mapped buffer */
+   PerlIO_flush(f);
+   /* If flush took the "buffer" see if we have one from before */
+   if (!b->buf && m->bbuf)
+    b->buf = m->bbuf;
+   if (!b->buf)
+    {
+     PerlIOBuf_get_base(f);
+     m->bbuf = b->buf;
+    }
+  }
+return PerlIOBuf_unread(f,vbuf,count);
 }
 
-#undef PerlIO_set_ptrcnt
-void
-PerlIO_set_ptrcnt(PerlIO *f, STDCHAR *ptr, int cnt)
+SSize_t
+PerlIOMmap_write(PerlIO *f, const void *vbuf, Size_t count)
 {
- if (f)
+ PerlIOMmap *m = PerlIOSelf(f,PerlIOMmap);
+ PerlIOBuf  *b = &m->base;
+ if (!b->buf || !(PerlIOBase(f)->flags & PERLIO_F_WRBUF))
   {
-   dTHX;
-   if (!f->buf)
-    PerlIO_alloc_buf(f);
-   f->ptr = ptr;
-   assert(f->ptr >= f->buf);
-   if (PerlIO_get_cnt(f) != cnt)
+   /* No, or wrong sort of, buffer */
+   if (m->len)
     {
-     dTHX;
-     assert(PerlIO_get_cnt(f) != cnt);
+     if (PerlIOMmap_unmap(f) != 0)
+      return 0;
+    }
+   /* If unmap took the "buffer" see if we have one from before */
+   if (!b->buf && m->bbuf)
+    b->buf = m->bbuf;
+   if (!b->buf)
+    {
+     PerlIOBuf_get_base(f);
+     m->bbuf = b->buf;
     }
-   f->flags |= PERLIO_F_RDBUF;
   }
+ return PerlIOBuf_write(f,vbuf,count);
 }
 
-#undef PerlIO_get_bufsiz
-int
-PerlIO_get_bufsiz(PerlIO *f)
+IV
+PerlIOMmap_flush(PerlIO *f)
 {
- if (f)
+ PerlIOMmap *m = PerlIOSelf(f,PerlIOMmap);
+ PerlIOBuf  *b = &m->base;
+ IV code = PerlIOBuf_flush(f);
+ /* Now we are "synced" at PerlIOBuf level */
+ if (b->buf)
   {
-   if (!f->buf)
-    PerlIO_alloc_buf(f);
-   return f->bufsiz;
+   if (m->len)
+    {
+     /* Unmap the buffer */
+     if (PerlIOMmap_unmap(f) != 0)
+      code = -1;
+    }
+   else
+    {
+     /* We seem to have a PerlIOBuf buffer which was not mapped
+      * remember it in case we need one later
+      */
+     m->bbuf = b->buf;
+    }
   }
- return -1;
+ return code;
 }
 
-#undef PerlIO_get_ptr
-STDCHAR *
-PerlIO_get_ptr(PerlIO *f)
+IV
+PerlIOMmap_fill(PerlIO *f)
 {
- if (f)
+ PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
+ IV code = PerlIO_flush(f);
+ if (code == 0 && !b->buf)
   {
-   if (!f->buf)
-    PerlIO_alloc_buf(f);
-   return f->ptr;
+   code = PerlIOMmap_map(f);
   }
- return NULL;
+ if (code == 0 && !(PerlIOBase(f)->flags & PERLIO_F_RDBUF))
+  {
+   code = PerlIOBuf_fill(f);
+  }
+ return code;
 }
 
-#undef PerlIO_get_base
-STDCHAR *
-PerlIO_get_base(PerlIO *f)
+IV
+PerlIOMmap_close(PerlIO *f)
 {
- if (f)
+ PerlIOMmap *m = PerlIOSelf(f,PerlIOMmap);
+ PerlIOBuf  *b = &m->base;
+ IV code = PerlIO_flush(f);
+ if (m->bbuf)
   {
-   if (!f->buf)
-    PerlIO_alloc_buf(f);
-   return f->buf;
+   b->buf  = m->bbuf;
+   m->bbuf = NULL;
+   b->ptr  = b->end = b->buf;
   }
- return NULL;
+ if (PerlIOBuf_close(f) != 0)
+  code = -1;
+ return code;
 }
 
-#undef PerlIO_has_base
-int
-PerlIO_has_base(PerlIO *f)
+
+PerlIO_funcs PerlIO_mmap = {
+ "mmap",
+ sizeof(PerlIOMmap),
+ PERLIO_K_BUFFERED,
+ PerlIOBase_fileno,
+ PerlIOBuf_fdopen,
+ PerlIOBuf_open,
+ PerlIOBuf_reopen,
+ PerlIOBuf_pushed,
+ PerlIOBase_noop_ok,
+ PerlIOBuf_read,
+ PerlIOMmap_unread,
+ PerlIOMmap_write,
+ PerlIOBuf_seek,
+ PerlIOBuf_tell,
+ PerlIOBuf_close,
+ PerlIOMmap_flush,
+ PerlIOMmap_fill,
+ PerlIOBase_eof,
+ PerlIOBase_error,
+ PerlIOBase_clearerr,
+ PerlIOBuf_setlinebuf,
+ PerlIOMmap_get_base,
+ PerlIOBuf_bufsiz,
+ PerlIOBuf_get_ptr,
+ PerlIOBuf_get_cnt,
+ PerlIOBuf_set_ptrcnt,
+};
+
+#endif /* HAS_MMAP */
+
+void
+PerlIO_init(void)
 {
- if (f)
+ if (!_perlio)
   {
-   if (!f->buf)
-    PerlIO_alloc_buf(f);
-   return f->buf != NULL;
+#ifndef WIN32
+   atexit(&PerlIO_cleanup);
+#endif
   }
 }
 
-#undef PerlIO_puts
-int
-PerlIO_puts(PerlIO *f, const char *s)
+#undef PerlIO_stdin
+PerlIO *
+PerlIO_stdin(void)
 {
- STRLEN len = strlen(s);
- return PerlIO_write(f,s,len);
+ if (!_perlio)
+  PerlIO_stdstreams();
+ return &_perlio[1];
 }
 
-#undef PerlIO_eof
-int
-PerlIO_eof(PerlIO *f)
+#undef PerlIO_stdout
+PerlIO *
+PerlIO_stdout(void)
 {
- if (f)
-  {
-   return (f->flags & PERLIO_F_EOF) != 0;
-  }
- return 1;
+ if (!_perlio)
+  PerlIO_stdstreams();
+ return &_perlio[2];
+}
+
+#undef PerlIO_stderr
+PerlIO *
+PerlIO_stderr(void)
+{
+ if (!_perlio)
+  PerlIO_stdstreams();
+ return &_perlio[3];
 }
 
+/*--------------------------------------------------------------------------------------*/
+
 #undef PerlIO_getname
 char *
 PerlIO_getname(PerlIO *f, char *buf)
 {
-#ifdef VMS
- return fgetname(f,buf);
-#else
  dTHX;
  Perl_croak(aTHX_ "Don't know how to get file name");
  return NULL;
-#endif
-}
-
-#undef PerlIO_ungetc
-int
-PerlIO_ungetc(PerlIO *f, int ch)
-{
- if (f->buf && (f->flags & PERLIO_F_RDBUF) && f->ptr > f->buf)
-  {
-   *--(f->ptr) = ch;
-   PerlIO_debug(__FUNCTION__ " f=%p c=%c\n",f,ch);
-   return ch;
-  }
- PerlIO_debug(__FUNCTION__ " f=%p c=%c - cannot\n",f,ch);
- return -1;
 }
 
-#undef PerlIO_read
-SSize_t
-PerlIO_read(PerlIO *f, void *vbuf, Size_t count)
-{
- STDCHAR *buf = (STDCHAR *) vbuf;
- if (f)
-  {
-   Size_t got = 0;
-   if (!f->ptr)
-    PerlIO_alloc_buf(f);
 
-   while (count > 0)
-    {
-     SSize_t avail = (f->end - f->ptr);
-     if ((SSize_t) count < avail)
-      avail = count;
-     if (avail > 0)
-      {
-       Copy(f->ptr,buf,avail,char);
-       got     += avail;
-       f->ptr  += avail;
-       count   -= avail;
-       buf     += avail;
-      }
-     if (count && (f->ptr >= f->end))
-      {
-       PerlIO_flush(f);
-       f->ptr = f->end = f->buf;
-       avail = read(f->fd,f->ptr,f->bufsiz);
-       if (avail <= 0)
-        {
-         if (avail == 0)
-          f->flags |= PERLIO_F_EOF;
-         else if (errno == EINTR)
-          continue;
-         else
-          f->flags |= PERLIO_F_ERROR;
-         break;
-        }
-       f->end   = f->buf+avail;
-       f->flags |= PERLIO_F_RDBUF;
-      }
-    }
-   return got;
-  }
- return 0;
-}
+/*--------------------------------------------------------------------------------------*/
+/* Functions which can be called on any kind of PerlIO implemented
+   in terms of above
+*/
 
 #undef PerlIO_getc
 int
 PerlIO_getc(PerlIO *f)
 {
- STDCHAR buf;
- int count = PerlIO_read(f,&buf,1);
+ STDCHAR buf[1];
+ SSize_t count = PerlIO_read(f,buf,1);
  if (count == 1)
-  return buf;
- return -1;
-}
-
-#undef PerlIO_error
-int
-PerlIO_error(PerlIO *f)
-{
- if (f)
-  {
-   return f->flags & PERLIO_F_ERROR;
-  }
- return 1;
-}
-
-#undef PerlIO_clearerr
-void
-PerlIO_clearerr(PerlIO *f)
-{
- if (f)
-  {
-   f->flags &= ~PERLIO_F_ERROR;
-  }
-}
-
-#undef PerlIO_setlinebuf
-void
-PerlIO_setlinebuf(PerlIO *f)
-{
- if (f)
   {
-   f->flags &= ~PERLIO_F_LINEBUF;
+   return (unsigned char) buf[0];
   }
+ return EOF;
 }
 
-#undef PerlIO_write
-SSize_t
-PerlIO_write(PerlIO *f, const void *vbuf, Size_t count)
+#undef PerlIO_ungetc
+int
+PerlIO_ungetc(PerlIO *f, int ch)
 {
- const STDCHAR *buf = (const STDCHAR *) vbuf;
- Size_t written = 0;
- PerlIO_debug(__FUNCTION__ " f=%p c=%d\n",f,count);
- if (f)
+ if (ch != EOF)
   {
-   if (!f->buf)
-    PerlIO_alloc_buf(f);
-   while (count > 0)
-    {
-     SSize_t avail = f->bufsiz - (f->ptr - f->buf);
-     if ((SSize_t) count < avail)
-      avail = count;
-     f->flags |= PERLIO_F_WRBUF;
-     if (1 || (f->flags & PERLIO_F_LINEBUF))
-      {
-       while (avail > 0)
-        {
-         int ch = *buf++;
-         *(f->ptr)++ = ch;
-         count--;
-         avail--;
-         written++;
-         if (ch == '\n')
-          {
-           PerlIO_flush(f);
-           break;
-          }
-        }
-      }
-     else
-      {
-       if (avail)
-        {
-         Copy(buf,f->ptr,avail,char);
-         count   -= avail;
-         buf     += avail;
-         written += avail;
-         f->ptr  += avail;
-        }
-      }
-     if (f->ptr >= (f->buf + f->bufsiz))
-      PerlIO_flush(f);
-    }
+   STDCHAR buf = ch;
+   if (PerlIO_unread(f,&buf,1) == 1)
+    return ch;
   }
- return written;
+ return EOF;
 }
 
 #undef PerlIO_putc
@@ -793,41 +3060,15 @@ int
 PerlIO_putc(PerlIO *f, int ch)
 {
  STDCHAR buf = ch;
- PerlIO_write(f,&ch,1);
+ return PerlIO_write(f,&buf,1);
 }
 
-#undef PerlIO_tell
-Off_t
-PerlIO_tell(PerlIO *f)
-{
- Off_t posn = f->posn;
- if (f->buf)
-  posn += (f->ptr - f->buf);
- PerlIO_debug(__FUNCTION__ " f=%p r=%ld b=%p p=%p e=%ld\n",
-              f,(long)f->posn,f->buf,f->ptr,(long)posn);
- return posn;
-}
-
-#undef PerlIO_seek
+#undef PerlIO_puts
 int
-PerlIO_seek(PerlIO *f, Off_t offset, int whence)
+PerlIO_puts(PerlIO *f, const char *s)
 {
- int code;
- PerlIO_debug(__FUNCTION__ " f=%p i=%ld+%d\n",f,(long)f->posn,(f->ptr-f->buf));
- code = PerlIO_flush(f);
- if (code == 0)
-  {
-   f->flags &= ~PERLIO_F_EOF;
-   f->posn = PerlLIO_lseek(f->fd,offset,whence);
-   PerlIO_debug(__FUNCTION__ " f=%p o=%ld w=%d p=%ld\n",
-                f,(long)offset,whence,(long)f->posn);
-   if (f->posn == (Off_t) -1)
-    {
-     f->posn = 0;
-     code = -1;
-    }
-  }
- return code;
+ STRLEN len = strlen(s);
+ return PerlIO_write(f,s,len);
 }
 
 #undef PerlIO_rewind
@@ -835,6 +3076,7 @@ void
 PerlIO_rewind(PerlIO *f)
 {
  PerlIO_seek(f,(Off_t)0,SEEK_SET);
+ PerlIO_clearerr(f);
 }
 
 #undef PerlIO_vprintf
@@ -845,7 +3087,13 @@ PerlIO_vprintf(PerlIO *f, const char *fmt, va_list ap)
  SV *sv = newSVpvn("",0);
  char *s;
  STRLEN len;
+#ifdef NEED_VA_COPY
+ va_list apc;
+ Perl_va_copy(ap, apc);
+ sv_vcatpvf(sv, fmt, &apc);
+#else
  sv_vcatpvf(sv, fmt, &ap);
+#endif
  s = SvPV(sv,len);
  return PerlIO_write(f,s,len);
 }
@@ -878,104 +3126,114 @@ PerlIO_stdoutf(const char *fmt,...)
 PerlIO *
 PerlIO_tmpfile(void)
 {
+ /* I have no idea how portable mkstemp() is ... */
+#if defined(WIN32) || !defined(HAVE_MKSTEMP)
+ dTHX;
+ PerlIO *f = NULL;
+ FILE *stdio = PerlSIO_tmpfile();
+ if (stdio)
+  {
+   PerlIOStdio *s = PerlIOSelf(PerlIO_push(f = PerlIO_allocate(aTHX),&PerlIO_stdio,"w+",Nullch,0),PerlIOStdio);
+   s->stdio  = stdio;
+  }
+ return f;
+#else
  dTHX;
  SV *sv = newSVpv("/tmp/PerlIO_XXXXXX",0);
  int fd = mkstemp(SvPVX(sv));
  PerlIO *f = NULL;
  if (fd >= 0)
   {
-   PerlIO *f = PerlIO_fdopen(fd,"w+");
+   f = PerlIO_fdopen(fd,"w+");
    if (f)
     {
-     f->flags |= PERLIO_F_TEMP;
+     PerlIOBase(f)->flags |= PERLIO_F_TEMP;
     }
-   unlink(SvPVX(sv));
+   PerlLIO_unlink(SvPVX(sv));
    SvREFCNT_dec(sv);
   }
  return f;
-}
-
-#undef PerlIO_importFILE
-PerlIO *
-PerlIO_importFILE(FILE *f, int fl)
-{
- int fd = fileno(f);
- return PerlIO_fdopen(fd,"r+");
-}
-
-#undef PerlIO_exportFILE
-FILE *
-PerlIO_exportFILE(PerlIO *f, int fl)
-{
- PerlIO_flush(f);
- 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)
-{
+#endif
 }
 
 #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)
+PerlIO_setpos(PerlIO *f, SV *pos)
 {
- return PerlIO_seek(f,*pos,0);
+ dTHX;
+ if (SvOK(pos))
+  {
+   STRLEN len;
+   Off_t *posn = (Off_t *) SvPV(pos,len);
+   if (f && len == sizeof(Off_t))
+    return PerlIO_seek(f,*posn,SEEK_SET);
+  }
+ errno = EINVAL;
+ return -1;
 }
 #else
-#ifndef PERLIO_IS_STDIO
 #undef PerlIO_setpos
 int
-PerlIO_setpos(PerlIO *f, const Fpos_t *pos)
+PerlIO_setpos(PerlIO *f, SV *pos)
 {
+ dTHX;
+ if (SvOK(pos))
+  {
+   STRLEN len;
+   Fpos_t *fpos = (Fpos_t *) SvPV(pos,len);
+   if (f && len == sizeof(Fpos_t))
+    {
 #if defined(USE_64_BIT_STDIO) && defined(USE_FSETPOS64)
- return fsetpos64(f, pos);
+     return fsetpos64(f, fpos);
 #else
- return fsetpos(f, pos);
+     return fsetpos(f, fpos);
 #endif
+    }
+  }
+ errno = EINVAL;
+ return -1;
 }
 #endif
-#endif
 
 #ifndef HAS_FGETPOS
 #undef PerlIO_getpos
 int
-PerlIO_getpos(PerlIO *f, Fpos_t *pos)
+PerlIO_getpos(PerlIO *f, SV *pos)
 {
- *pos = PerlIO_tell(f);
- return 0;
+ dTHX;
+ Off_t posn = PerlIO_tell(f);
+ sv_setpvn(pos,(char *)&posn,sizeof(posn));
+ return (posn == (Off_t)-1) ? -1 : 0;
 }
 #else
-#ifndef PERLIO_IS_STDIO
 #undef PerlIO_getpos
 int
-PerlIO_getpos(PerlIO *f, Fpos_t *pos)
+PerlIO_getpos(PerlIO *f, SV *pos)
 {
+ dTHX;
+ Fpos_t fpos;
+ int code;
 #if defined(USE_64_BIT_STDIO) && defined(USE_FSETPOS64)
- return fgetpos64(f, pos);
+ code = fgetpos64(f, &fpos);
 #else
- return fgetpos(f, pos);
+ code = fgetpos(f, &fpos);
 #endif
+ sv_setpvn(pos,(char *)&fpos,sizeof(fpos));
+ return code;
 }
 #endif
-#endif
 
 #if (defined(PERLIO_IS_STDIO) || !defined(USE_SFIO)) && !defined(HAS_VPRINTF)
 
@@ -1005,7 +3263,8 @@ PerlIO_vsprintf(char *s, int n, const char *fmt, va_list ap)
    if (strlen(s) >= (STRLEN)n)
     {
      dTHX;
-     PerlIO_puts(Perl_error_log,"panic: sprintf overflow - memory corrupted!\n");
+     (void)PerlIO_puts(Perl_error_log,
+		       "panic: sprintf overflow - memory corrupted!\n");
      my_exit(1);
     }
   }
@@ -1026,5 +3285,4 @@ PerlIO_sprintf(char *s, int n, const char *fmt,...)
 }
 #endif
 
-#endif /* !PERL_IMPLICIT_SYS */