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 } 198