contrib/readline-5.0/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
  36 #if defined (HAVE_UNISTD_H)
  37 #  ifdef _MINIX
  38 #    include <sys/types.h>
  39 #  endif
  40 #  include <unistd.h>
  41 #endif
  42
  43 #include "history.h"
  44 #include "histlib.h"
  45
  46 /* The list of alternate characters that can delimit a history search
  47    string. */
  48 char *history_search_delimiter_chars = (char *)NULL;
  49
  50 static int history_search_internal PARAMS((const char *, int, int));
  51
  52 /* Search the history for STRING, starting at history_offset.
  53    If DIRECTION < 0, then the search is through previous entries, else
  54    through subsequent.  If ANCHORED is non-zero, the string must
  55    appear at the beginning of a history line, otherwise, the string
  56    may appear anywhere in the line.  If the string is found, then
  57    current_history () is the history entry, and the value of this
  58    function is the offset in the line of that history entry that the
  59    string was found in.  Otherwise, nothing is changed, and a -1 is
  60    returned. */
  61
  62 static int
  63 history_search_internal (string, direction, anchored)
  64      const char *string;
  65      int direction, anchored;
  66 {
  67   register int i, reverse;
  68   register char *line;
  69   register int line_index;
  70   int string_len;
  71   HIST_ENTRY **the_history;     /* local */
  72
  73   i = history_offset;
  74   reverse = (direction < 0);
  75
  76   /* Take care of trivial cases first. */
  77   if (string == 0 || *string == '\0')
  78     return (-1);
  79
  80   if (!history_length || ((i >= history_length) && !reverse))
  81     return (-1);
  82
  83   if (reverse && (i >= history_length))
  84     i = history_length - 1;
  85
  86 #define NEXT_LINE() do { if (reverse) i--; else i++; } while (0)
  87
  88   the_history = history_list ();
  89   string_len = strlen (string);
  90   while (1)
  91     {
  92       /* Search each line in the history list for STRING. */
  93
  94       /* At limit for direction? */
  95       if ((reverse && i < 0) || (!reverse && i == history_length))
  96         return (-1);
  97
  98       line = the_history[i]->line;
  99       line_index = strlen (line);
 100
 101       /* If STRING is longer than line, no match. */
 102       if (string_len > line_index)
 103         {
 104           NEXT_LINE ();
 105           continue;
 106         }
 107
 108       /* Handle anchored searches first. */
 109       if (anchored == ANCHORED_SEARCH)
 110         {
 111           if (STREQN (string, line, string_len))
 112             {
 113               history_offset = i;
 114               return (0);
 115             }
 116
 117           NEXT_LINE ();
 118           continue;
 119         }
 120
 121       /* Do substring search. */
 122       if (reverse)
 123         {
 124           line_index -= string_len;
 125
 126           while (line_index >= 0)
 127             {
 128               if (STREQN (string, line + line_index, string_len))
 129                 {
 130                   history_offset = i;
 131                   return (line_index);
 132                 }
 133               line_index--;
 134             }
 135         }
 136       else
 137         {
 138           register int limit;
 139
 140           limit = line_index - string_len + 1;
 141           line_index = 0;
 142
 143           while (line_index < limit)
 144             {
 145               if (STREQN (string, line + line_index, string_len))
 146                 {
 147                   history_offset = i;
 148                   return (line_index);
 149                 }
 150               line_index++;
 151             }
 152         }
 153       NEXT_LINE ();
 154     }
 155 }
 156
 157 /* Do a non-anchored search for STRING through the history in DIRECTION. */
 158 int
 159 history_search (string, direction)
 160      const char *string;
 161      int direction;
 162 {
 163   return (history_search_internal (string, direction, NON_ANCHORED_SEARCH));
 164 }
 165
 166 /* Do an anchored search for string through the history in DIRECTION. */
 167 int
 168 history_search_prefix (string, direction)
 169      const char *string;
 170      int direction;
 171 {
 172   return (history_search_internal (string, direction, ANCHORED_SEARCH));
 173 }
 174
 175 /* Search for STRING in the history list.  DIR is < 0 for searching
 176    backwards.  POS is an absolute index into the history list at
 177    which point to begin searching. */
 178 int
 179 history_search_pos (string, dir, pos)
 180      const char *string;
 181      int dir, pos;
 182 {
 183   int ret, old;
 184
 185   old = where_history ();
 186   history_set_pos (pos);
 187   if (history_search (string, dir) == -1)
 188     {
 189       history_set_pos (old);
 190       return (-1);
 191     }
 192   ret = where_history ();
 193   history_set_pos (old);
 194   return ret;
 195 }