Add readline 8.2 to third_party

third_party/readline/history.c

@@ -0,0 +1,613 @@
+/* history.c -- standalone history library */
+
+/* Copyright (C) 1989-2021 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 (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);
+}
+
+/* Are we currently at the end of the history list? */
+int
+_hs_at_end_of_history (void)
+{
+  return (the_history == 0 || history_offset == history_length);
+}
+ 
+/* 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))
+    {
+      /* 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 = old_value->timestamp ? savestring (old_value->timestamp) : 0;
+  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;
+  (void)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 */
+}