-/* history.c -- standalone history library */
-
-/* Copyright (C) 1989-2017 Free Software Foundation, Inc.
-
- This file contains the GNU History Library (History), a set of
- routines for managing the text of previously typed lines.
-
- History 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 3 of the License, or
- (at your option) any later version.
-
- History 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.
-
- You should have received a copy of the GNU General Public License
- along with History. If not, see <http://www.gnu.org/licenses/>.
-*/
-
-/* 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
-
-#include <errno.h>
-
-#include "history.h"
-#include "histlib.h"
-
-#include "xmalloc.h"
-
-#if !defined (errno)
-extern int errno;
-#endif
-
-/* How big to make the_history when we first allocate it. */
-#define DEFAULT_HISTORY_INITIAL_SIZE 502
-
-#define MAX_HISTORY_INITIAL_SIZE 8192
-
-/* The number of slots to increase the_history by. */
-#define DEFAULT_HISTORY_GROW_SIZE 50
-
-static char *hist_inittime PARAMS((void));
-
-/* **************************************************************** */
-/* */
-/* 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;
-
-/* The current number of slots allocated to the input_history. */
-static int history_size;
-
-/* If HISTORY_STIFLED is non-zero, then this is the maximum number of
- entries to remember. */
-int history_max_entries;
-int max_input_history; /* backwards compatibility */
-
-/* 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 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 (void)
-{
- 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 (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 (void)
-{
- 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 and the associated
- timestamps. */
-int
-history_total_bytes (void)
-{
- register int i, result;
-
- for (i = result = 0; the_history && the_history[i]; i++)
- result += HISTENT_BYTES (the_history[i]);
-
- 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 (void)
-{
- 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 (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 careful, 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 (void)
-{
- 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 (void)
-{
- 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 (void)
-{
- 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 (void)
-{
- 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 (int offset)
-{
- int local_index;
-
- local_index = offset - history_base;
- return (local_index >= history_length || local_index < 0 || the_history == 0)
- ? (HIST_ENTRY *)NULL
- : the_history[local_index];
-}
-
-HIST_ENTRY *
-alloc_history_entry (char *string, char *ts)
-{
- HIST_ENTRY *temp;
-
- temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY));
-
- temp->line = string ? savestring (string) : string;
- temp->data = (char *)NULL;
- temp->timestamp = ts;
-
- return temp;
-}
-
-time_t
-history_get_time (HIST_ENTRY *hist)
-{
- char *ts;
- time_t t;
-
- if (hist == 0 || hist->timestamp == 0)
- return 0;
- ts = hist->timestamp;
- if (ts[0] != history_comment_char)
- return 0;
- errno = 0;
- t = (time_t) strtol (ts + 1, (char **)NULL, 10); /* XXX - should use strtol() here */
- if (errno == ERANGE)
- return (time_t)0;
- return t;
-}
-
-static char *
-hist_inittime (void)
-{
- time_t t;
- char ts[64], *ret;
-
- t = (time_t) time ((time_t *)0);
-#if defined (HAVE_VSNPRINTF) /* assume snprintf if vsnprintf exists */
- snprintf (ts, sizeof (ts) - 1, "X%lu", (unsigned long) t);
-#else
- sprintf (ts, "X%lu", (unsigned long) t);
-#endif
- ret = savestring (ts);
- ret[0] = history_comment_char;
-
- return ret;
-}
-
-/* Place STRING at the end of the history list. The data field
- is set to NULL. */
-void
-add_history (const char *string)
-{
- HIST_ENTRY *temp;
- int new_length;
-
- if (history_stifled && (history_length == history_max_entries))
- {
- register int i;
-
- /* If the history is stifled, and history_length is zero,
- and it equals history_max_entries, we don't save items. */
- if (history_length == 0)
- return;
-
- /* If there is something in the slot, then remove it. */
- if (the_history[0])
- (void) free_history_entry (the_history[0]);
-
- /* Copy the rest of the entries, moving down one slot. Copy includes
- trailing NULL. */
- memmove (the_history, the_history + 1, history_length * sizeof (HIST_ENTRY *));
-
- new_length = history_length;
- history_base++;
- }
- else
- {
- if (history_size == 0)
- {
- if (history_stifled && history_max_entries > 0)
- history_size = (history_max_entries > MAX_HISTORY_INITIAL_SIZE)
- ? MAX_HISTORY_INITIAL_SIZE
- : history_max_entries + 2;
- else
- history_size = DEFAULT_HISTORY_INITIAL_SIZE;
- the_history = (HIST_ENTRY **)xmalloc (history_size * sizeof (HIST_ENTRY *));
- new_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 *));
- }
- new_length = history_length + 1;
- }
- }
-
- temp = alloc_history_entry ((char *)string, hist_inittime ());
-
- the_history[new_length] = (HIST_ENTRY *)NULL;
- the_history[new_length - 1] = temp;
- history_length = new_length;
-}
-
-/* Change the time stamp of the most recent history entry to STRING. */
-void
-add_history_time (const char *string)
-{
- HIST_ENTRY *hs;
-
- if (string == 0 || history_length < 1)
- return;
- hs = the_history[history_length - 1];
- FREE (hs->timestamp);
- hs->timestamp = savestring (string);
-}
-
-/* Free HIST and return the data so the calling application can free it
- if necessary and desired. */
-histdata_t
-free_history_entry (HIST_ENTRY *hist)
-{
- histdata_t x;
-
- if (hist == 0)
- return ((histdata_t) 0);
- FREE (hist->line);
- FREE (hist->timestamp);
- x = hist->data;
- xfree (hist);
- return (x);
-}
-
-HIST_ENTRY *
-copy_history_entry (HIST_ENTRY *hist)
-{
- HIST_ENTRY *ret;
- char *ts;
-
- if (hist == 0)
- return hist;
-
- ret = alloc_history_entry (hist->line, (char *)NULL);
-
- ts = hist->timestamp ? savestring (hist->timestamp) : hist->timestamp;
- ret->timestamp = ts;
-
- ret->data = hist->data;
-
- return ret;
-}
-
-/* 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 (int which, const char *line, histdata_t data)
-{
- HIST_ENTRY *temp, *old_value;
-
- if (which < 0 || which >= history_length)
- return ((HIST_ENTRY *)NULL);
-
- temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY));
- old_value = the_history[which];
-
- temp->line = savestring (line);
- temp->data = data;
- temp->timestamp = savestring (old_value->timestamp);
- the_history[which] = temp;
-
- return (old_value);
-}
-
-/* Append LINE to the history line at offset WHICH, adding a newline to the
- end of the current line first. This can be used to construct multi-line
- history entries while reading lines from the history file. */
-void
-_hs_append_history_line (int which, const char *line)
-{
- HIST_ENTRY *hent;
- size_t newlen, curlen, minlen;
- char *newline;
-
- hent = the_history[which];
- curlen = strlen (hent->line);
- minlen = curlen + strlen (line) + 2; /* min space needed */
- if (curlen > 256) /* XXX - for now */
- {
- newlen = 512; /* now realloc in powers of 2 */
- /* we recalcluate every time; the operations are cheap */
- while (newlen < minlen)
- newlen <<= 1;
- }
- else
- newlen = minlen;
- /* Assume that realloc returns the same pointer and doesn't try a new
- alloc/copy if the new size is the same as the one last passed. */
- newline = realloc (hent->line, newlen);
- if (newline)
- {
- hent->line = newline;
- hent->line[curlen++] = '\n';
- strcpy (hent->line + curlen, line);
- }
-}
-
-/* Replace the DATA in the specified history entries, replacing OLD with
- NEW. WHICH says which one(s) to replace: WHICH == -1 means to replace
- all of the history entries where entry->data == OLD; WHICH == -2 means
- to replace the `newest' history entry where entry->data == OLD; and
- WHICH >= 0 means to replace that particular history entry's data, as
- long as it matches OLD. */
-void
-_hs_replace_history_data (int which, histdata_t *old, histdata_t *new)
-{
- HIST_ENTRY *entry;
- register int i, last;
-
- if (which < -2 || which >= history_length || history_length == 0 || the_history == 0)
- return;
-
- if (which >= 0)
- {
- entry = the_history[which];
- if (entry && entry->data == old)
- entry->data = new;
- return;
- }
-
- last = -1;
- for (i = 0; i < history_length; i++)
- {
- entry = the_history[i];
- if (entry == 0)
- continue;
- if (entry->data == old)
- {
- last = i;
- if (which == -1)
- entry->data = new;
- }
- }
- if (which == -2 && last >= 0)
- {
- entry = the_history[last];
- entry->data = new; /* XXX - we don't check entry->old */
- }
-}
-
-/* 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 (int which)
-{
- HIST_ENTRY *return_value;
- register int i;
-#if 1
- int nentries;
- HIST_ENTRY **start, **end;
-#endif
-
- if (which < 0 || which >= history_length || history_length == 0 || the_history == 0)
- return ((HIST_ENTRY *)NULL);
-
- return_value = the_history[which];
-
-#if 1
- /* Copy the rest of the entries, moving down one slot. Copy includes
- trailing NULL. */
- nentries = history_length - which;
- start = the_history + which;
- end = start + 1;
- memmove (start, end, nentries * sizeof (HIST_ENTRY *));
-#else
- for (i = which; i < history_length; i++)
- the_history[i] = the_history[i + 1];
-#endif
-
- history_length--;
-
- return (return_value);
-}
-
-HIST_ENTRY **
-remove_history_range (int first, int last)
-{
- HIST_ENTRY **return_value;
- register int i;
- int nentries;
- HIST_ENTRY **start, **end;
-
- if (the_history == 0 || history_length == 0)
- return ((HIST_ENTRY **)NULL);
- if (first < 0 || first >= history_length || last < 0 || last >= history_length)
- return ((HIST_ENTRY **)NULL);
- if (first > last)
- return (HIST_ENTRY **)NULL;
-
- nentries = last - first + 1;
- return_value = (HIST_ENTRY **)malloc ((nentries + 1) * sizeof (HIST_ENTRY *));
- if (return_value == 0)
- return return_value;
-
- /* Return all the deleted entries in a list */
- for (i = first ; i <= last; i++)
- return_value[i - first] = the_history[i];
- return_value[i - first] = (HIST_ENTRY *)NULL;
-
- /* Copy the rest of the entries, moving down NENTRIES slots. Copy includes
- trailing NULL. */
- start = the_history + first;
- end = the_history + last + 1;
- memmove (start, end, (history_length - last) * sizeof (HIST_ENTRY *));
-
- history_length -= nentries;
-
- return (return_value);
-}
-
-/* Stifle the history list, remembering only MAX number of lines. */
-void
-stifle_history (int max)
-{
- register int i, j;
-
- if (max < 0)
- max = 0;
-
- if (history_length > max)
- {
- /* This loses because we cannot free the data. */
- for (i = 0, j = history_length - max; i < j; i++)
- free_history_entry (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 = history_max_entries = max;
-}
-
-/* Stop stifling the history. This returns the previous maximum
- number of history entries. The value is positive if the history
- was stifled, negative if it wasn't. */
-int
-unstifle_history (void)
-{
- if (history_stifled)
- {
- history_stifled = 0;
- return (history_max_entries);
- }
- else
- return (-history_max_entries);
-}
-
-int
-history_is_stifled (void)
-{
- return (history_stifled);
-}
-
-void
-clear_history (void)
-{
- register int i;
-
- /* This loses because we cannot free the data. */
- for (i = 0; i < history_length; i++)
- {
- free_history_entry (the_history[i]);
- the_history[i] = (HIST_ENTRY *)NULL;
- }
-
- history_offset = history_length = 0;
- history_base = 1; /* reset history base to default */
-}