Initial creation of sourceware repository

1 files changed, 388 insertions, 0 deletions

diff --git a/readline/history.c b/readline/history.c
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+/* History.c -- standalone history library */
+
+/* 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 1, 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,
+   675 Mass Ave, Cambridge, MA 02139, 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
+
+#if defined (HAVE_CONFIG_H)
+#  include <config.h>
+#endif
+
+#include <stdio.h>
+
+#if defined (HAVE_STDLIB_H)
+#  include <stdlib.h>
+#else
+#  include "ansi_stdlib.h"
+#endif /* HAVE_STDLIB_H */
+
+#if defined (HAVE_UNISTD_H)
+#  ifdef _MINIX
+#    include <sys/types.h>
+#  endif
+#  include <unistd.h>
+#endif
+
+#if defined (HAVE_STRING_H)
+#  include <string.h>
+#else
+#  include <strings.h>
+#endif /* !HAVE_STRING_H */
+
+#include "history.h"
+#include "histlib.h"
+
+extern char *xmalloc (), *xrealloc ();
+
+/* The number of slots to increase the_history by. */
+#define DEFAULT_HISTORY_GROW_SIZE 50
+
+/* **************************************************************** */
+/*								    */
+/*			History Functions			    */
+/*								    */
+/* **************************************************************** */
+
+/* An array of HIST_ENTRY.  This is where we store the history. */
+static HIST_ENTRY **the_history = (HIST_ENTRY **)NULL;
+
+/* Non-zero means that we have enforced a limit on the amount of
+   history that we save. */
+static int history_stifled;
+
+/* If HISTORY_STIFLED is non-zero, then this is the maximum number of
+   entries to remember. */
+int max_input_history;
+
+/* The current location of the interactive history pointer.  Just makes
+   life easier for outside callers. */
+int history_offset;
+
+/* The number of strings currently stored in the history list. */
+int history_length;
+
+/* The current number of slots allocated to the input_history. */
+static int history_size;
+
+/* The logical `base' of the history array.  It defaults to 1. */
+int history_base = 1;
+
+/* Return the current HISTORY_STATE of the history. */
+HISTORY_STATE *
+history_get_history_state ()
+{
+  HISTORY_STATE *state;
+
+  state = (HISTORY_STATE *)xmalloc (sizeof (HISTORY_STATE));
+  state->entries = the_history;
+  state->offset = history_offset;
+  state->length = history_length;
+  state->size = history_size;
+  state->flags = 0;
+  if (history_stifled)
+    state->flags |= HS_STIFLED;
+
+  return (state);
+}
+
+/* Set the state of the current history array to STATE. */
+void
+history_set_history_state (state)
+     HISTORY_STATE *state;
+{
+  the_history = state->entries;
+  history_offset = state->offset;
+  history_length = state->length;
+  history_size = state->size;
+  if (state->flags & HS_STIFLED)
+    history_stifled = 1;
+}
+
+/* Begin a session in which the history functions might be used.  This
+   initializes interactive variables. */
+void
+using_history ()
+{
+  history_offset = history_length;
+}
+
+/* Return the number of bytes that the primary history entries are using.
+   This just adds up the lengths of the_history->lines. */
+int
+history_total_bytes ()
+{
+  register int i, result;
+
+  result = 0;
+
+  for (i = 0; the_history && the_history[i]; i++)
+    result += strlen (the_history[i]->line);
+
+  return (result);
+}
+
+/* Returns the magic number which says what history element we are
+   looking at now.  In this implementation, it returns history_offset. */
+int
+where_history ()
+{
+  return (history_offset);
+}
+
+/* Make the current history item be the one at POS, an absolute index.
+   Returns zero if POS is out of range, else non-zero. */
+int
+history_set_pos (pos)
+     int pos;
+{
+  if (pos > history_length || pos < 0 || !the_history)
+    return (0);
+  history_offset = pos;
+  return (1);
+}
+ 
+/* Return the current history array.  The caller has to be carefull, since this
+   is the actual array of data, and could be bashed or made corrupt easily.
+   The array is terminated with a NULL pointer. */
+HIST_ENTRY **
+history_list ()
+{
+  return (the_history);
+}
+
+/* Return the history entry at the current position, as determined by
+   history_offset.  If there is no entry there, return a NULL pointer. */
+HIST_ENTRY *
+current_history ()
+{
+  return ((history_offset == history_length) || the_history == 0)
+		? (HIST_ENTRY *)NULL
+		: the_history[history_offset];
+}
+
+/* Back up history_offset to the previous history entry, and return
+   a pointer to that entry.  If there is no previous entry then return
+   a NULL pointer. */
+HIST_ENTRY *
+previous_history ()
+{
+  return history_offset ? the_history[--history_offset] : (HIST_ENTRY *)NULL;
+}
+
+/* Move history_offset forward to the next history entry, and return
+   a pointer to that entry.  If there is no next entry then return a
+   NULL pointer. */
+HIST_ENTRY *
+next_history ()
+{
+  return (history_offset == history_length) ? (HIST_ENTRY *)NULL : the_history[++history_offset];
+}
+
+/* Return the history entry which is logically at OFFSET in the history array.
+   OFFSET is relative to history_base. */
+HIST_ENTRY *
+history_get (offset)
+     int offset;
+{
+  int local_index;
+
+  local_index = offset - history_base;
+  return (local_index >= history_length || local_index < 0 || !the_history)
+		? (HIST_ENTRY *)NULL
+		: the_history[local_index];
+}
+
+/* Place STRING at the end of the history list.  The data field
+   is  set to NULL. */
+void
+add_history (string)
+     char *string;
+{
+  HIST_ENTRY *temp;
+
+  if (history_stifled && (history_length == max_input_history))
+    {
+      register int i;
+
+      /* If the history is stifled, and history_length is zero,
+	 and it equals max_input_history, we don't save items. */
+      if (history_length == 0)
+	return;
+
+      /* If there is something in the slot, then remove it. */
+      if (the_history[0])
+	{
+	  free (the_history[0]->line);
+	  free (the_history[0]);
+	}
+
+      /* Copy the rest of the entries, moving down one slot. */
+      for (i = 0; i < history_length; i++)
+	the_history[i] = the_history[i + 1];
+
+      history_base++;
+    }
+  else
+    {
+      if (history_size == 0)
+	{
+	  history_size = DEFAULT_HISTORY_GROW_SIZE;
+	  the_history = (HIST_ENTRY **)xmalloc (history_size * sizeof (HIST_ENTRY *));
+	  history_length = 1;
+	}
+      else
+	{
+	  if (history_length == (history_size - 1))
+	    {
+	      history_size += DEFAULT_HISTORY_GROW_SIZE;
+	      the_history = (HIST_ENTRY **)
+		xrealloc (the_history, history_size * sizeof (HIST_ENTRY *));
+	    }
+	  history_length++;
+	}
+    }
+
+  temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY));
+  temp->line = savestring (string);
+  temp->data = (char *)NULL;
+
+  the_history[history_length] = (HIST_ENTRY *)NULL;
+  the_history[history_length - 1] = temp;
+}
+
+/* Make the history entry at WHICH have LINE and DATA.  This returns
+   the old entry so you can dispose of the data.  In the case of an
+   invalid WHICH, a NULL pointer is returned. */
+HIST_ENTRY *
+replace_history_entry (which, line, data)
+     int which;
+     char *line;
+     char *data;
+{
+  HIST_ENTRY *temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY));
+  HIST_ENTRY *old_value;
+
+  if (which >= history_length)
+    return ((HIST_ENTRY *)NULL);
+
+  old_value = the_history[which];
+
+  temp->line = savestring (line);
+  temp->data = data;
+  the_history[which] = temp;
+
+  return (old_value);
+}
+
+/* Remove history element WHICH from the history.  The removed
+   element is returned to you so you can free the line, data,
+   and containing structure. */
+HIST_ENTRY *
+remove_history (which)
+     int which;
+{
+  HIST_ENTRY *return_value;
+
+  if (which >= history_length || !history_length)
+    return_value = (HIST_ENTRY *)NULL;
+  else
+    {
+      register int i;
+      return_value = the_history[which];
+
+      for (i = which; i < history_length; i++)
+	the_history[i] = the_history[i + 1];
+
+      history_length--;
+    }
+
+  return (return_value);
+}
+
+/* Stifle the history list, remembering only MAX number of lines. */
+void
+stifle_history (max)
+     int max;
+{
+  if (max < 0)
+    max = 0;
+
+  if (history_length > max)
+    {
+      register int i, j;
+
+      /* This loses because we cannot free the data. */
+      for (i = 0, j = history_length - max; i < j; i++)
+	{
+	  free (the_history[i]->line);
+	  free (the_history[i]);
+	}
+
+      history_base = i;
+      for (j = 0, i = history_length - max; j < max; i++, j++)
+	the_history[j] = the_history[i];
+      the_history[j] = (HIST_ENTRY *)NULL;
+      history_length = j;
+    }
+
+  history_stifled = 1;
+  max_input_history = max;
+}
+
+/* Stop stifling the history.  This returns the previous amount the 
+   history was stifled by.  The value is positive if the history was
+   stifled,  negative if it wasn't. */
+int
+unstifle_history ()
+{
+  if (history_stifled)
+    {
+      history_stifled = 0;
+      return (-max_input_history);
+    }
+
+  return (max_input_history);
+}
+
+int
+history_is_stifled ()
+{
+  return (history_stifled);
+}
+
+void
+clear_history ()
+{
+  register int i;
+
+  /* This loses because we cannot free the data. */
+  for (i = 0; i < history_length; i++)
+    {
+      free (the_history[i]->line);
+      free (the_history[i]);
+      the_history[i] = (HIST_ENTRY *)NULL;
+    }
+
+  history_offset = history_length = 0;
+}