--- gforth/engine/io.c	2003/03/09 15:17:03	1.16
+++ gforth/engine/io.c	2009/12/31 15:32:36	1.39
@@ -1,12 +1,12 @@
 /* direct key io driver
 
-  Copyright (C) 1995,1996,1997,1998,1999,2002 Free Software Foundation, Inc.
+  Copyright (C) 1995,1996,1997,1998,1999,2002,2003,2006,2007,2008,2009 Free Software Foundation, Inc.
 
   This file is part of Gforth.
 
   Gforth is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
-  as published by the Free Software Foundation; either version 2
+  as published by the Free Software Foundation, either version 3
   of the License, or (at your option) any later version.
 
   This program is distributed in the hope that it will be useful,
@@ -15,8 +15,7 @@
   GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License
-  along with this program; if not, write to the Free Software
-  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
+  along with this program; if not, see http://www.gnu.org/licenses/.
 
   The following is stolen from the readline library for bash
 */
@@ -40,6 +39,7 @@
 typedef unsigned int uint32_t;
 #endif
 
+#include <stdlib.h>
 #include <stdio.h>
 #include <signal.h>
 #include <string.h>
@@ -447,6 +447,8 @@ void deprep_terminal ()
 #define VTIME VEOL
 #endif
 
+#include <locale.h>
+
 void prep_terminal ()
 {
   int tty = fileno (stdin);
@@ -472,6 +474,9 @@ void prep_terminal ()
     return;      /* added by MdG */
   }      /* added by MdG */
    
+  setlocale(LC_ALL, "");
+  setlocale(LC_NUMERIC, "C");
+
   /* Try to keep this function from being INTerrupted.  We can do it
      on POSIX and systems with BSD-like signal handling. */
 #if defined (HAVE_POSIX_SIGNALS)
@@ -613,50 +618,77 @@ void deprep_terminal ()
 }
 #endif  /* NEW_TTY_DRIVER */
 
-/* If a character is available to be read, then read it
-   and stuff it into IBUFFER.  Otherwise, just return. */
+/* an ungetc() variant where we can know that there is a character waiting:
+   gf_ungetc: like ungetc
+   gf_regetc: call when reading a char, but does not get the character
+   gf_ungottenc: true if there is a char waiting
 
-long pending = -1L;
+   Implementation: just an array containing all the FILEs with ungotten chars.
+   Sequential search for membership checking (there should not be many elements)
+*/
 
-long key_avail (FILE * stream)
+static FILE **ungotten_files = NULL;
+static size_t n_ungotten = 0; /* actual number */
+static size_t max_ungotten = 0; /* buffer size */
+
+int gf_ungetc(int c, FILE *stream)
+/* like ungetc, but works with the others */
 {
-  int tty = fileno (stream);
-  int chars_avail = pending;
-  int result;
+  if (n_ungotten>=max_ungotten) {
+    max_ungotten = max_ungotten*2+1;
+    ungotten_files = realloc(ungotten_files, max_ungotten*sizeof(FILE *));
+  }
+  ungotten_files[n_ungotten++] = stream;
+  return ungetc(c, stream);
+}
 
-  if(!terminal_prepped)  prep_terminal();
+static long search_ungotten(FILE *stream)
+{
+  long i;
+  for (i=0; i<n_ungotten; i++)
+    if (ungotten_files[i] == stream)
+      return i;
+  return -1;
+}
 
-#if defined(FIONREAD) && !defined(_WIN32)
-  if(isatty (tty)) {
-    result = ioctl (tty, FIONREAD, &chars_avail);
-  }
-#else
-  {
-    fd_set selin;
-    static int now[2] = { 0 , 0 };
-    int res;
-    
-    FD_ZERO(&selin);
-    FD_SET(tty, &selin);
-    chars_avail=select(1, &selin, NULL, NULL, now);
-  }
-#endif
-  
-  if(chars_avail == -1L) {
-    unsigned char inchar;
-    
-    fcntl(tty, F_SETFL, O_NDELAY);
-    result = read(tty, &inchar, sizeof(char));
-    if(result == sizeof(char)) {
-      chars_avail = 1;
-      pending = (long)inchar;
-    } else {
-      chars_avail = 0;
-    }
-    fcntl(tty, F_SETFL, 0);
-  }
+void gf_regetc(FILE *stream)
+/* remove STREAM from ungotten_files */
+{
+  long i = search_ungotten(stream);
+  if (i>=0)
+    ungotten_files[i] = ungotten_files[--n_ungotten];
+}
 
-  return chars_avail;
+int gf_ungottenc(FILE *stream)
+/* true if stream has been ungotten */
+{
+  return search_ungotten(stream)>=0;
+}
+
+long key_avail (FILE *stream)
+{
+  int tty = fileno (stream);
+  fd_set selin;
+  static struct timeval now = { 0 , 0 };
+  int chars_avail;
+
+  if (gf_ungottenc(stream))
+    return 1;
+  setvbuf(stream, NULL, _IONBF, 0);
+  if(!terminal_prepped && stream == stdin)
+    prep_terminal();
+
+  FD_ZERO(&selin);
+  FD_SET(tty, &selin);
+  chars_avail = select(1, &selin, NULL, NULL, &now);
+  if (chars_avail > 0) {
+    /* getc won't block */
+    int c = getc(stream);
+    if (c==EOF)
+      return 0;
+    gf_ungetc(c, stream);
+  }
+  return (chars_avail == -1) ? 0 : chars_avail;
 }
 
 /* Get a key from the buffer of characters to be read.
@@ -671,35 +703,28 @@ Cell getkey(FILE * stream)
   Cell result;
   unsigned char c;
 
-  if(!terminal_prepped)
+  if (!gf_ungottenc(stream))
+    setvbuf(stream, NULL, _IONBF, 0);
+  if(!terminal_prepped && stream == stdin)
     prep_terminal();
 
-  while (pending < 0)
-    {
-      result = read (fileno (stream), &c, sizeof (char));
-
-      if (result == sizeof (char))
-        return /* (c == 0x7F ? 0x08 :*/ c /*)*/;
-
-      /* If zero characters are returned, then the file that we are
-	 reading from is empty!  Return EOF in that case. */
-      if (result == 0)
-	return (EOF);
-
-      /* If the error that we received was SIGINT, then try again,
-	 this is simply an interrupted system call to read ().
-	 Otherwise, some error ocurred, also signifying EOF. */
-      if (errno != EINTR)
-	return (EOF);
-    }
+  result = fread(&c, sizeof(c), 1, stream);
+  if (result>0)
+    gf_regetc(stream);
+  return result==0 ? (errno == EINTR ? 12 : 4) : c;
+}
 
-  /* otherwise there is a character pending;
-     return it and delete pending char */
-  result = (Cell) pending;
-  pending = -1L;
+#ifdef STANDALONE
+void emit_char(char x)
+{
+  putc(x, stdout);
+}
 
-  return result;
+void type_chars(char *addr, unsigned int l)
+{
+  fwrite(addr, l, 1, stdout);
 }
+#endif
 
 #ifdef TEST