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-rw-r--r--readline/history.c388
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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;
+}
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