1 files changed, 487 insertions, 487 deletions
diff --git a/MSVC/readline/histfile.c b/MSVC/readline/histfile.c
index 7fae4c1..b0279db 100644
--- a/MSVC/readline/histfile.c
+++ b/MSVC/readline/histfile.c
@@ -1,487 +1,487 @@
-/* histfile.c - functions to manipulate the history file. */
-
-/* Copyright (C) 1989, 1992 Free Software Foundation, Inc.
-
-   This file contains the GNU History Library (the Library), a set of
-   routines for managing the text of previously typed lines.
-
-   The Library is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
-
-   The Library is distributed in the hope that it will be useful, but
-   WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   General Public License for more details.
-
-   The GNU General Public License is often shipped with GNU software, and
-   is generally kept in a file called COPYING or LICENSE.  If you do not
-   have a copy of the license, write to the Free Software Foundation,
-   59 Temple Place, Suite 330, Boston, MA 02111 USA. */
-
-/* The goal is to make the implementation transparent, so that you
-   don't have to know what data types are used, just what functions
-   you can call.  I think I have done that. */
-#define READLINE_LIBRARY
-
-#include "config.h"
-
-#include <stdio.h>
-
-#include <sys/types.h>
-#if !defined _MINIX && !defined _WIN32
-#  include <sys/file.h>
-#endif
-#include "posixstat.h"
-#include <fcntl.h>
-
-#if defined (HAVE_STDLIB_H)
-#  include <stdlib.h>
-#else
-#  include "ansi_stdlib.h"
-#endif /* HAVE_STDLIB_H */
-
-#if defined (HAVE_UNISTD_H)
-#  include <unistd.h>
-#endif
-
-#if defined (__EMX__) || defined (__CYGWIN__)
-#  undef HAVE_MMAP
-#endif
-
-#ifdef HAVE_MMAP
-#  include <sys/mman.h>
-
-#  ifdef MAP_FILE
-#    define MAP_RFLAGS	(MAP_FILE|MAP_PRIVATE)
-#    define MAP_WFLAGS	(MAP_FILE|MAP_SHARED)
-#  else
-#    define MAP_RFLAGS	MAP_PRIVATE
-#    define MAP_WFLAGS	MAP_SHARED
-#  endif
-
-#  ifndef MAP_FAILED
-#    define MAP_FAILED	((void *)-1)
-#  endif
-
-#endif /* HAVE_MMAP */
-
-/* If we're compiling for __EMX__ (OS/2) or __CYGWIN__ (cygwin32 environment
-   on win 95/98/nt), we want to open files with O_BINARY mode so that there
-   is no \n -> \r\n conversion performed.  On other systems, we don't want to
-   mess around with O_BINARY at all, so we ensure that it's defined to 0. */
-#if defined (__EMX__) || defined (__CYGWIN__)
-#  ifndef O_BINARY
-#    define O_BINARY 0
-#  endif
-#else /* !__EMX__ && !__CYGWIN__ */
-#  undef O_BINARY
-#  define O_BINARY 0
-#endif /* !__EMX__ && !__CYGWIN__ */
-
-#include <errno.h>
-#if !defined (errno)
-extern int errno;
-#endif /* !errno */
-
-#if defined _WIN32
-# include "rlconf.h"
-#endif	/* _WIN32  */
-
-#include "history.h"
-#include "histlib.h"
-
-#include "rlshell.h"
-#include "xmalloc.h"
-
-/* Return the string that should be used in the place of this
-   filename.  This only matters when you don't specify the
-   filename to read_history (), or write_history (). */
-static char *
-history_filename (filename)
-     const char *filename;
-{
-  char *return_val;
-  const char *home;
-  int home_len;
-
-  return_val = filename ? savestring (filename) : (char *)NULL;
-
-  if (return_val)
-    return (return_val);
-  
-  home = sh_get_env_value ("HOME");
-
-  if (home == 0)
-    {
-#if defined _WIN32 && defined INITFILES_IN_REGISTRY
-      return_val = get_user_registry_string(READLINE_REGKEY, HISTFILE_REGVAL);
-      if (return_val)
-        return (return_val);
-      free(return_val);
-#endif	/* _WIN32 ... */
-      home = ".";
-      home_len = 1;
-    }
-  else
-    home_len = strlen (home);
-
-  return_val = (char *)xmalloc (2 + home_len + 8); /* strlen(".history") == 8 */
-  strcpy (return_val, home);
-  return_val[home_len] = '/';
-#if defined (__MSDOS__)
-  strcpy (return_val + home_len + 1, "_history");
-#else
-  strcpy (return_val + home_len + 1, ".history");
-#endif
-
-  return (return_val);
-}
-
-/* Add the contents of FILENAME to the history list, a line at a time.
-   If FILENAME is NULL, then read from ~/.history.  Returns 0 if
-   successful, or errno if not. */
-int
-read_history (filename)
-     const char *filename;
-{
-  return (read_history_range (filename, 0, -1));
-}
-
-/* Read a range of lines from FILENAME, adding them to the history list.
-   Start reading at the FROM'th line and end at the TO'th.  If FROM
-   is zero, start at the beginning.  If TO is less than FROM, read
-   until the end of the file.  If FILENAME is NULL, then read from
-   ~/.history.  Returns 0 if successful, or errno if not. */
-int
-read_history_range (filename, from, to)
-     const char *filename;
-     int from, to;
-{
-  register char *line_start, *line_end;
-  char *input, *buffer, *bufend;
-  int file, current_line, chars_read;
-  struct stat finfo;
-  size_t file_size;
-
-  buffer = (char *)NULL;
-  input = history_filename (filename);
-  file = open (input, O_RDONLY|O_BINARY, 0666);
-
-  if ((file < 0) || (fstat (file, &finfo) == -1))
-    goto error_and_exit;
-
-  file_size = (size_t)finfo.st_size;
-
-  /* check for overflow on very large files */
-  if (file_size != finfo.st_size || file_size + 1 < file_size)
-    {
-#if defined (EFBIG)
-      errno = EFBIG;
-#elif defined (EOVERFLOW)
-      errno = EOVERFLOW;
-#endif
-      goto error_and_exit;
-    }
-
-#ifdef HAVE_MMAP
-  /* We map read/write and private so we can change newlines to NULs without
-     affecting the underlying object. */
-  buffer = (char *)mmap (0, file_size, PROT_READ|PROT_WRITE, MAP_RFLAGS, file, 0);
-  if ((void *)buffer == MAP_FAILED)
-    goto error_and_exit;
-  chars_read = file_size;
-#else
-  buffer = (char *)malloc (file_size + 1);
-  if (buffer == 0)
-    goto error_and_exit;
-
-  chars_read = read (file, buffer, file_size);
-#endif
-  if (chars_read < 0)
-    {
-  error_and_exit:
-      chars_read = errno;
-      if (file >= 0)
-	close (file);
-
-      FREE (input);
-#ifndef HAVE_MMAP
-      FREE (buffer);
-#endif
-
-      return (chars_read);
-    }
-
-  close (file);
-
-  /* Set TO to larger than end of file if negative. */
-  if (to < 0)
-    to = chars_read;
-
-  /* Start at beginning of file, work to end. */
-  bufend = buffer + chars_read;
-  current_line = 0;
-
-  /* Skip lines until we are at FROM. */
-  for (line_start = line_end = buffer; line_end < bufend && current_line < from; line_end++)
-    if (*line_end == '\n')
-      {
-	current_line++;
-	line_start = line_end + 1;
-      }
-
-  /* If there are lines left to gobble, then gobble them now. */
-  for (line_end = line_start; line_end < bufend; line_end++)
-    if (*line_end == '\n')
-      {
-	*line_end = '\0';
-
-	if (*line_start)
-	  add_history (line_start);
-
-	current_line++;
-
-	if (current_line >= to)
-	  break;
-
-	line_start = line_end + 1;
-      }
-
-  FREE (input);
-#ifndef HAVE_MMAP
-  FREE (buffer);
-#else
-  munmap (buffer, file_size);
-#endif
-
-  return (0);
-}
-
-/* Truncate the history file FNAME, leaving only LINES trailing lines.
-   If FNAME is NULL, then use ~/.history.  Returns 0 on success, errno
-   on failure. */
-int
-history_truncate_file (fname, lines)
-     const char *fname;
-     int lines;
-{
-  char *buffer, *filename, *bp;
-  int file, chars_read, rv;
-  struct stat finfo;
-  size_t file_size;
-
-  buffer = (char *)NULL;
-  filename = history_filename (fname);
-  file = open (filename, O_RDONLY|O_BINARY, 0666);
-  rv = 0;
-
-  /* Don't try to truncate non-regular files. */
-  if (file == -1 || fstat (file, &finfo) == -1)
-    {
-      rv = errno;
-      if (file != -1)
-	close (file);
-      goto truncate_exit;
-    }
-
-  if (S_ISREG (finfo.st_mode) == 0)
-    {
-      close (file);
-#ifdef EFTYPE
-      rv = EFTYPE;
-#else
-      rv = EINVAL;
-#endif
-      goto truncate_exit;
-    }
-
-  file_size = (size_t)finfo.st_size;
-
-  /* check for overflow on very large files */
-  if (file_size != finfo.st_size || file_size + 1 < file_size)
-    {
-      close (file);
-#if defined (EFBIG)
-      rv = errno = EFBIG;
-#elif defined (EOVERFLOW)
-      rv = errno = EOVERFLOW;
-#else
-      rv = errno = EINVAL;
-#endif
-      goto truncate_exit;
-    }
-
-  buffer = (char *)malloc (file_size + 1);
-  if (buffer == 0)
-    {
-      close (file);
-      goto truncate_exit;
-    }
-
-  chars_read = read (file, buffer, file_size);
-  close (file);
-
-  if (chars_read <= 0)
-    {
-      rv = (chars_read < 0) ? errno : 0;
-      goto truncate_exit;
-    }
-
-  /* Count backwards from the end of buffer until we have passed
-     LINES lines. */
-  for (bp = buffer + chars_read - 1; lines && bp > buffer; bp--)
-    {
-      if (*bp == '\n')
-	lines--;
-    }
-
-  /* If this is the first line, then the file contains exactly the
-     number of lines we want to truncate to, so we don't need to do
-     anything.  It's the first line if we don't find a newline between
-     the current value of i and 0.  Otherwise, write from the start of
-     this line until the end of the buffer. */
-  for ( ; bp > buffer; bp--)
-    if (*bp == '\n')
-      {
-	bp++;
-	break;
-      }
-
-  /* Write only if there are more lines in the file than we want to
-     truncate to. */
-  if (bp > buffer && ((file = open (filename, O_WRONLY|O_TRUNC|O_BINARY, 0600)) != -1))
-    {
-      write (file, bp, chars_read - (bp - buffer));
-
-#if defined (__BEOS__)
-      /* BeOS ignores O_TRUNC. */
-      ftruncate (file, chars_read - (bp - buffer));
-#endif
-
-      close (file);
-    }
-
- truncate_exit:
-
-  FREE (buffer);
-
-  free (filename);
-  return rv;
-}
-
-/* Workhorse function for writing history.  Writes NELEMENT entries
-   from the history list to FILENAME.  OVERWRITE is non-zero if you
-   wish to replace FILENAME with the entries. */
-static int
-history_do_write (filename, nelements, overwrite)
-     const char *filename;
-     int nelements, overwrite;
-{
-  register int i;
-  char *output;
-  int file, mode, rv;
-  size_t cursize;
-
-#ifdef HAVE_MMAP
-  mode = overwrite ? O_RDWR|O_CREAT|O_TRUNC|O_BINARY : O_RDWR|O_APPEND|O_BINARY;
-#else
-  mode = overwrite ? O_WRONLY|O_CREAT|O_TRUNC|O_BINARY : O_WRONLY|O_APPEND|O_BINARY;
-#endif
-  output = history_filename (filename);
-  rv = 0;
-
-  if ((file = open (output, mode, 0600)) == -1)
-    {
-      FREE (output);
-      return (errno);
-    }
-
-#ifdef HAVE_MMAP
-  cursize = overwrite ? 0 : lseek (file, 0, SEEK_END);
-#endif
-
-  if (nelements > history_length)
-    nelements = history_length;
-
-  /* Build a buffer of all the lines to write, and write them in one syscall.
-     Suggested by Peter Ho (peter@robosts.oxford.ac.uk). */
-  {
-    HIST_ENTRY **the_history;	/* local */
-    register int j;
-    int buffer_size;
-    char *buffer;
-
-    the_history = history_list ();
-    /* Calculate the total number of bytes to write. */
-    for (buffer_size = 0, i = history_length - nelements; i < history_length; i++)
-      buffer_size += 1 + strlen (the_history[i]->line);
-
-    /* Allocate the buffer, and fill it. */
-#ifdef HAVE_MMAP
-    if (ftruncate (file, buffer_size+cursize) == -1)
-      goto mmap_error;
-    buffer = (char *)mmap (0, buffer_size, PROT_READ|PROT_WRITE, MAP_WFLAGS, file, cursize);
-    if ((void *)buffer == MAP_FAILED)
-      {
-mmap_error:
-	rv = errno;
-	FREE (output);
-	close (file);
-	return rv;
-      }
-#else    
-    buffer = (char *)malloc (buffer_size);
-    if (buffer == 0)
-      {
-      	rv = errno;
-	FREE (output);
-	close (file);
-	return rv;
-      }
-#endif
-
-    for (j = 0, i = history_length - nelements; i < history_length; i++)
-      {
-	strcpy (buffer + j, the_history[i]->line);
-	j += strlen (the_history[i]->line);
-	buffer[j++] = '\n';
-      }
-
-#ifdef HAVE_MMAP
-    if (msync (buffer, buffer_size, 0) != 0 || munmap (buffer, buffer_size) != 0)
-      rv = errno;
-#else
-    if (write (file, buffer, buffer_size) < 0)
-      rv = errno;
-    free (buffer);
-#endif
-  }
-
-  close (file);
-
-  FREE (output);
-
-  return (rv);
-}
-
-/* Append NELEMENT entries to FILENAME.  The entries appended are from
-   the end of the list minus NELEMENTs up to the end of the list. */
-int
-append_history (nelements, filename)
-     int nelements;
-     const char *filename;
-{
-  return (history_do_write (filename, nelements, HISTORY_APPEND));
-}
-
-/* Overwrite FILENAME with the current history.  If FILENAME is NULL,
-   then write the history list to ~/.history.  Values returned
-   are as in read_history ().*/
-int
-write_history (filename)
-     const char *filename;
-{
-  return (history_do_write (filename, history_length, HISTORY_OVERWRITE));
-}
+/* histfile.c - functions to manipulate the history file. */
+
+/* Copyright (C) 1989, 1992 Free Software Foundation, Inc.
+
+   This file contains the GNU History Library (the Library), a set of
+   routines for managing the text of previously typed lines.
+
+   The Library is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   The Library is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   The GNU General Public License is often shipped with GNU software, and
+   is generally kept in a file called COPYING or LICENSE.  If you do not
+   have a copy of the license, write to the Free Software Foundation,
+   59 Temple Place, Suite 330, Boston, MA 02111 USA. */
+
+/* The goal is to make the implementation transparent, so that you
+   don't have to know what data types are used, just what functions
+   you can call.  I think I have done that. */
+#define READLINE_LIBRARY
+
+#include "config.h"
+
+#include <stdio.h>
+
+#include <sys/types.h>
+#if !defined _MINIX && !defined _WIN32
+#  include <sys/file.h>
+#endif
+#include "posixstat.h"
+#include <fcntl.h>
+
+#if defined (HAVE_STDLIB_H)
+#  include <stdlib.h>
+#else
+#  include "ansi_stdlib.h"
+#endif /* HAVE_STDLIB_H */
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#if defined (__EMX__) || defined (__CYGWIN__)
+#  undef HAVE_MMAP
+#endif
+
+#ifdef HAVE_MMAP
+#  include <sys/mman.h>
+
+#  ifdef MAP_FILE
+#    define MAP_RFLAGS	(MAP_FILE|MAP_PRIVATE)
+#    define MAP_WFLAGS	(MAP_FILE|MAP_SHARED)
+#  else
+#    define MAP_RFLAGS	MAP_PRIVATE
+#    define MAP_WFLAGS	MAP_SHARED
+#  endif
+
+#  ifndef MAP_FAILED
+#    define MAP_FAILED	((void *)-1)
+#  endif
+
+#endif /* HAVE_MMAP */
+
+/* If we're compiling for __EMX__ (OS/2) or __CYGWIN__ (cygwin32 environment
+   on win 95/98/nt), we want to open files with O_BINARY mode so that there
+   is no \n -> \r\n conversion performed.  On other systems, we don't want to
+   mess around with O_BINARY at all, so we ensure that it's defined to 0. */
+#if defined (__EMX__) || defined (__CYGWIN__)
+#  ifndef O_BINARY
+#    define O_BINARY 0
+#  endif
+#else /* !__EMX__ && !__CYGWIN__ */
+#  undef O_BINARY
+#  define O_BINARY 0
+#endif /* !__EMX__ && !__CYGWIN__ */
+
+#include <errno.h>
+#if !defined (errno)
+extern int errno;
+#endif /* !errno */
+
+#if defined _WIN32
+# include "rlconf.h"
+#endif	/* _WIN32  */
+
+#include "history.h"
+#include "histlib.h"
+
+#include "rlshell.h"
+#include "xmalloc.h"
+
+/* Return the string that should be used in the place of this
+   filename.  This only matters when you don't specify the
+   filename to read_history (), or write_history (). */
+static char *
+history_filename (filename)
+     const char *filename;
+{
+  char *return_val;
+  const char *home;
+  int home_len;
+
+  return_val = filename ? savestring (filename) : (char *)NULL;
+
+  if (return_val)
+    return (return_val);
+  
+  home = sh_get_env_value ("HOME");
+
+  if (home == 0)
+    {
+#if defined _WIN32 && defined INITFILES_IN_REGISTRY
+      return_val = get_user_registry_string(READLINE_REGKEY, HISTFILE_REGVAL);
+      if (return_val)
+        return (return_val);
+      free(return_val);
+#endif	/* _WIN32 ... */
+      home = ".";
+      home_len = 1;
+    }
+  else
+    home_len = strlen (home);
+
+  return_val = (char *)xmalloc (2 + home_len + 8); /* strlen(".history") == 8 */
+  strcpy (return_val, home);
+  return_val[home_len] = '/';
+#if defined (__MSDOS__)
+  strcpy (return_val + home_len + 1, "_history");
+#else
+  strcpy (return_val + home_len + 1, ".history");
+#endif
+
+  return (return_val);
+}
+
+/* Add the contents of FILENAME to the history list, a line at a time.
+   If FILENAME is NULL, then read from ~/.history.  Returns 0 if
+   successful, or errno if not. */
+int
+read_history (filename)
+     const char *filename;
+{
+  return (read_history_range (filename, 0, -1));
+}
+
+/* Read a range of lines from FILENAME, adding them to the history list.
+   Start reading at the FROM'th line and end at the TO'th.  If FROM
+   is zero, start at the beginning.  If TO is less than FROM, read
+   until the end of the file.  If FILENAME is NULL, then read from
+   ~/.history.  Returns 0 if successful, or errno if not. */
+int
+read_history_range (filename, from, to)
+     const char *filename;
+     int from, to;
+{
+  register char *line_start, *line_end;
+  char *input, *buffer, *bufend;
+  int file, current_line, chars_read;
+  struct stat finfo;
+  size_t file_size;
+
+  buffer = (char *)NULL;
+  input = history_filename (filename);
+  file = open (input, O_RDONLY|O_BINARY, 0666);
+
+  if ((file < 0) || (fstat (file, &finfo) == -1))
+    goto error_and_exit;
+
+  file_size = (size_t)finfo.st_size;
+
+  /* check for overflow on very large files */
+  if (file_size != finfo.st_size || file_size + 1 < file_size)
+    {
+#if defined (EFBIG)
+      errno = EFBIG;
+#elif defined (EOVERFLOW)
+      errno = EOVERFLOW;
+#endif
+      goto error_and_exit;
+    }
+
+#ifdef HAVE_MMAP
+  /* We map read/write and private so we can change newlines to NULs without
+     affecting the underlying object. */
+  buffer = (char *)mmap (0, file_size, PROT_READ|PROT_WRITE, MAP_RFLAGS, file, 0);
+  if ((void *)buffer == MAP_FAILED)
+    goto error_and_exit;
+  chars_read = file_size;
+#else
+  buffer = (char *)malloc (file_size + 1);
+  if (buffer == 0)
+    goto error_and_exit;
+
+  chars_read = read (file, buffer, file_size);
+#endif
+  if (chars_read < 0)
+    {
+  error_and_exit:
+      chars_read = errno;
+      if (file >= 0)
+	close (file);
+
+      FREE (input);
+#ifndef HAVE_MMAP
+      FREE (buffer);
+#endif
+
+      return (chars_read);
+    }
+
+  close (file);
+
+  /* Set TO to larger than end of file if negative. */
+  if (to < 0)
+    to = chars_read;
+
+  /* Start at beginning of file, work to end. */
+  bufend = buffer + chars_read;
+  current_line = 0;
+
+  /* Skip lines until we are at FROM. */
+  for (line_start = line_end = buffer; line_end < bufend && current_line < from; line_end++)
+    if (*line_end == '\n')
+      {
+	current_line++;
+	line_start = line_end + 1;
+      }
+
+  /* If there are lines left to gobble, then gobble them now. */
+  for (line_end = line_start; line_end < bufend; line_end++)
+    if (*line_end == '\n')
+      {
+	*line_end = '\0';
+
+	if (*line_start)
+	  add_history (line_start);
+
+	current_line++;
+
+	if (current_line >= to)
+	  break;
+
+	line_start = line_end + 1;
+      }
+
+  FREE (input);
+#ifndef HAVE_MMAP
+  FREE (buffer);
+#else
+  munmap (buffer, file_size);
+#endif
+
+  return (0);
+}
+
+/* Truncate the history file FNAME, leaving only LINES trailing lines.
+   If FNAME is NULL, then use ~/.history.  Returns 0 on success, errno
+   on failure. */
+int
+history_truncate_file (fname, lines)
+     const char *fname;
+     int lines;
+{
+  char *buffer, *filename, *bp;
+  int file, chars_read, rv;
+  struct stat finfo;
+  size_t file_size;
+
+  buffer = (char *)NULL;
+  filename = history_filename (fname);
+  file = open (filename, O_RDONLY|O_BINARY, 0666);
+  rv = 0;
+
+  /* Don't try to truncate non-regular files. */
+  if (file == -1 || fstat (file, &finfo) == -1)
+    {
+      rv = errno;
+      if (file != -1)
+	close (file);
+      goto truncate_exit;
+    }
+
+  if (S_ISREG (finfo.st_mode) == 0)
+    {
+      close (file);
+#ifdef EFTYPE
+      rv = EFTYPE;
+#else
+      rv = EINVAL;
+#endif
+      goto truncate_exit;
+    }
+
+  file_size = (size_t)finfo.st_size;
+
+  /* check for overflow on very large files */
+  if (file_size != finfo.st_size || file_size + 1 < file_size)
+    {
+      close (file);
+#if defined (EFBIG)
+      rv = errno = EFBIG;
+#elif defined (EOVERFLOW)
+      rv = errno = EOVERFLOW;
+#else
+      rv = errno = EINVAL;
+#endif
+      goto truncate_exit;
+    }
+
+  buffer = (char *)malloc (file_size + 1);
+  if (buffer == 0)
+    {
+      close (file);
+      goto truncate_exit;
+    }
+
+  chars_read = read (file, buffer, file_size);
+  close (file);
+
+  if (chars_read <= 0)
+    {
+      rv = (chars_read < 0) ? errno : 0;
+      goto truncate_exit;
+    }
+
+  /* Count backwards from the end of buffer until we have passed
+     LINES lines. */
+  for (bp = buffer + chars_read - 1; lines && bp > buffer; bp--)
+    {
+      if (*bp == '\n')
+	lines--;
+    }
+
+  /* If this is the first line, then the file contains exactly the
+     number of lines we want to truncate to, so we don't need to do
+     anything.  It's the first line if we don't find a newline between
+     the current value of i and 0.  Otherwise, write from the start of
+     this line until the end of the buffer. */
+  for ( ; bp > buffer; bp--)
+    if (*bp == '\n')
+      {
+	bp++;
+	break;
+      }
+
+  /* Write only if there are more lines in the file than we want to
+     truncate to. */
+  if (bp > buffer && ((file = open (filename, O_WRONLY|O_TRUNC|O_BINARY, 0600)) != -1))
+    {
+      write (file, bp, chars_read - (bp - buffer));
+
+#if defined (__BEOS__)
+      /* BeOS ignores O_TRUNC. */
+      ftruncate (file, chars_read - (bp - buffer));
+#endif
+
+      close (file);
+    }
+
+ truncate_exit:
+
+  FREE (buffer);
+
+  free (filename);
+  return rv;
+}
+
+/* Workhorse function for writing history.  Writes NELEMENT entries
+   from the history list to FILENAME.  OVERWRITE is non-zero if you
+   wish to replace FILENAME with the entries. */
+static int
+history_do_write (filename, nelements, overwrite)
+     const char *filename;
+     int nelements, overwrite;
+{
+  register int i;
+  char *output;
+  int file, mode, rv;
+  size_t cursize;
+
+#ifdef HAVE_MMAP
+  mode = overwrite ? O_RDWR|O_CREAT|O_TRUNC|O_BINARY : O_RDWR|O_APPEND|O_BINARY;
+#else
+  mode = overwrite ? O_WRONLY|O_CREAT|O_TRUNC|O_BINARY : O_WRONLY|O_APPEND|O_BINARY;
+#endif
+  output = history_filename (filename);
+  rv = 0;
+
+  if ((file = open (output, mode, 0600)) == -1)
+    {
+      FREE (output);
+      return (errno);
+    }
+
+#ifdef HAVE_MMAP
+  cursize = overwrite ? 0 : lseek (file, 0, SEEK_END);
+#endif
+
+  if (nelements > history_length)
+    nelements = history_length;
+
+  /* Build a buffer of all the lines to write, and write them in one syscall.
+     Suggested by Peter Ho (peter@robosts.oxford.ac.uk). */
+  {
+    HIST_ENTRY **the_history;	/* local */
+    register int j;
+    int buffer_size;
+    char *buffer;
+
+    the_history = history_list ();
+    /* Calculate the total number of bytes to write. */
+    for (buffer_size = 0, i = history_length - nelements; i < history_length; i++)
+      buffer_size += 1 + strlen (the_history[i]->line);
+
+    /* Allocate the buffer, and fill it. */
+#ifdef HAVE_MMAP
+    if (ftruncate (file, buffer_size+cursize) == -1)
+      goto mmap_error;
+    buffer = (char *)mmap (0, buffer_size, PROT_READ|PROT_WRITE, MAP_WFLAGS, file, cursize);
+    if ((void *)buffer == MAP_FAILED)
+      {
+mmap_error:
+	rv = errno;
+	FREE (output);
+	close (file);
+	return rv;
+      }
+#else    
+    buffer = (char *)malloc (buffer_size);
+    if (buffer == 0)
+      {
+      	rv = errno;
+	FREE (output);
+	close (file);
+	return rv;
+      }
+#endif
+
+    for (j = 0, i = history_length - nelements; i < history_length; i++)
+      {
+	strcpy (buffer + j, the_history[i]->line);
+	j += strlen (the_history[i]->line);
+	buffer[j++] = '\n';
+      }
+
+#ifdef HAVE_MMAP
+    if (msync (buffer, buffer_size, 0) != 0 || munmap (buffer, buffer_size) != 0)
+      rv = errno;
+#else
+    if (write (file, buffer, buffer_size) < 0)
+      rv = errno;
+    free (buffer);
+#endif
+  }
+
+  close (file);
+
+  FREE (output);
+
+  return (rv);
+}
+
+/* Append NELEMENT entries to FILENAME.  The entries appended are from
+   the end of the list minus NELEMENTs up to the end of the list. */
+int
+append_history (nelements, filename)
+     int nelements;
+     const char *filename;
+{
+  return (history_do_write (filename, nelements, HISTORY_APPEND));
+}
+
+/* Overwrite FILENAME with the current history.  If FILENAME is NULL,
+   then write the history list to ~/.history.  Values returned
+   are as in read_history ().*/
+int
+write_history (filename)
+     const char *filename;
+{
+  return (history_do_write (filename, history_length, HISTORY_OVERWRITE));
+}