readline/histsearch.c

   1 /* histsearch.c -- searching the history list. */
   2
   3 /* Copyright (C) 1989, 1992 Free Software Foundation, Inc.
   4
   5    This file contains the GNU History Library (the Library), a set of
   6    routines for managing the text of previously typed lines.
   7
   8    The Library is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2, or (at your option)
  11    any later version.
  12
  13    The Library is distributed in the hope that it will be useful, but
  14    WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16    General Public License for more details.
  17
  18    The GNU General Public License is often shipped with GNU software, and
  19    is generally kept in a file called COPYING or LICENSE.  If you do not
  20    have a copy of the license, write to the Free Software Foundation,
  21    59 Temple Place, Suite 330, Boston, MA 02111 USA. */
  22
  23 #define READLINE_LIBRARY
  24
  25 #if defined (HAVE_CONFIG_H)
  26 #  include <config.h>
  27 #endif
  28
  29 #include <stdio.h>
  30 #if defined (HAVE_STDLIB_H)
  31 #  include <stdlib.h>
  32 #else
  33 #  include "ansi_stdlib.h"
  34 #endif /* HAVE_STDLIB_H */
  35 #if defined (HAVE_UNISTD_H)
  36 #  ifdef _MINIX
  37 #    include <sys/types.h>
  38 #  endif
  39 #  include <unistd.h>
  40 #endif
  41 #if defined (HAVE_STRING_H)
  42 #  include <string.h>
  43 #else
  44 #  include <strings.h>
  45 #endif /* !HAVE_STRING_H */
  46
  47 #include "history.h"
  48 #include "histlib.h"
  49
  50 /* The list of alternate characters that can delimit a history search
  51    string. */
  52 char *history_search_delimiter_chars = (char *)NULL;
  53
  54 /* Search the history for STRING, starting at history_offset.
  55    If DIRECTION < 0, then the search is through previous entries, else
  56    through subsequent.  If ANCHORED is non-zero, the string must
  57    appear at the beginning of a history line, otherwise, the string
  58    may appear anywhere in the line.  If the string is found, then
  59    current_history () is the history entry, and the value of this
  60    function is the offset in the line of that history entry that the
  61    string was found in.  Otherwise, nothing is changed, and a -1 is
  62    returned. */
  63
  64 static int
  65 history_search_internal (string, direction, anchored)
  66      char *string;
  67      int direction, anchored;
  68 {
  69   register int i, reverse;
  70   register char *line;
  71   register int line_index;
  72   int string_len;
  73   HIST_ENTRY **the_history;     /* local */
  74
  75   i = history_offset;
  76   reverse = (direction < 0);
  77
  78   /* Take care of trivial cases first. */
  79   if (string == 0 || *string == '\0')
  80     return (-1);
  81
  82   if (!history_length || ((i == history_length) && !reverse))
  83     return (-1);
  84
  85   if (reverse && (i == history_length))
  86     i--;
  87
  88 #define NEXT_LINE() do { if (reverse) i--; else i++; } while (0)
  89
  90   the_history = history_list ();
  91   string_len = strlen (string);
  92   while (1)
  93     {
  94       /* Search each line in the history list for STRING. */
  95
  96       /* At limit for direction? */
  97       if ((reverse && i < 0) || (!reverse && i == history_length))
  98         return (-1);
  99
 100       line = the_history[i]->line;
 101       line_index = strlen (line);
 102
 103       /* If STRING is longer than line, no match. */
 104       if (string_len > line_index)
 105         {
 106           NEXT_LINE ();
 107           continue;
 108         }
 109
 110       /* Handle anchored searches first. */
 111       if (anchored == ANCHORED_SEARCH)
 112         {
 113           if (STREQN (string, line, string_len))
 114             {
 115               history_offset = i;
 116               return (0);
 117             }
 118
 119           NEXT_LINE ();
 120           continue;
 121         }
 122
 123       /* Do substring search. */
 124       if (reverse)
 125         {
 126           line_index -= string_len;
 127
 128           while (line_index >= 0)
 129             {
 130               if (STREQN (string, line + line_index, string_len))
 131                 {
 132                   history_offset = i;
 133                   return (line_index);
 134                 }
 135               line_index--;
 136             }
 137         }
 138       else
 139         {
 140           register int limit;
 141
 142           limit = line_index - string_len + 1;
 143           line_index = 0;
 144
 145           while (line_index < limit)
 146             {
 147               if (STREQN (string, line + line_index, string_len))
 148                 {
 149                   history_offset = i;
 150                   return (line_index);
 151                 }
 152               line_index++;
 153             }
 154         }
 155       NEXT_LINE ();
 156     }
 157 }
 158
 159 /* Do a non-anchored search for STRING through the history in DIRECTION. */
 160 int
 161 history_search (string, direction)
 162      char *string;
 163      int direction;
 164 {
 165   return (history_search_internal (string, direction, NON_ANCHORED_SEARCH));
 166 }
 167
 168 /* Do an anchored search for string through the history in DIRECTION. */
 169 int
 170 history_search_prefix (string, direction)
 171      char *string;
 172      int direction;
 173 {
 174   return (history_search_internal (string, direction, ANCHORED_SEARCH));
 175 }
 176
 177 /* Search for STRING in the history list.  DIR is < 0 for searching
 178    backwards.  POS is an absolute index into the history list at
 179    which point to begin searching. */
 180 int
 181 history_search_pos (string, dir, pos)
 182      char *string;
 183      int dir, pos;
 184 {
 185   int ret, old;
 186
 187   old = where_history ();
 188   history_set_pos (pos);
 189   if (history_search (string, dir) == -1)
 190     {
 191       history_set_pos (old);
 192       return (-1);
 193     }
 194   ret = where_history ();
 195   history_set_pos (old);
 196   return ret;
 197 }