1 /* histsearch.c -- searching the history list. */ 2 3 /* Copyright (C) 1989, 1992-2009 Free Software Foundation, Inc. 4 5 This file contains the GNU History Library (History), a set of 6 routines for managing the text of previously typed lines. 7 8 History 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 3 of the License, or 11 (at your option) any later version. 12 13 History is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with History. If not, see <http://www.gnu.org/licenses/>. 20 */ 21 22 #define READLINE_LIBRARY 23 24 #if defined (HAVE_CONFIG_H) 25 # include <config.h> 26 #endif 27 28 #include <stdio.h> 29 #if defined (HAVE_STDLIB_H) 30 # include <stdlib.h> 31 #else 32 # include "ansi_stdlib.h" 33 #endif /* HAVE_STDLIB_H */ 34 35 #if defined (HAVE_UNISTD_H) 36 # ifdef _MINIX 37 # include <sys/types.h> 38 # endif 39 # include <unistd.h> 40 #endif 41 42 #include "history.h" 43 #include "histlib.h" 44 45 /* The list of alternate characters that can delimit a history search 46 string. */ 47 char *history_search_delimiter_chars = (char *)NULL; 48 49 static int history_search_internal PARAMS((const char *, int, int)); 50 51 /* Search the history for STRING, starting at history_offset. 52 If DIRECTION < 0, then the search is through previous entries, else 53 through subsequent. If ANCHORED is non-zero, the string must 54 appear at the beginning of a history line, otherwise, the string 55 may appear anywhere in the line. If the string is found, then 56 current_history () is the history entry, and the value of this 57 function is the offset in the line of that history entry that the 58 string was found in. Otherwise, nothing is changed, and a -1 is 59 returned. */ 60 61 static int 62 history_search_internal (string, direction, anchored) 63 const char *string; 64 int direction, anchored; 65 { 66 register int i, reverse; 67 register char *line; 68 register int line_index; 69 int string_len; 70 HIST_ENTRY **the_history; /* local */ 71 72 i = history_offset; 73 reverse = (direction < 0); 74 75 /* Take care of trivial cases first. */ 76 if (string == 0 || *string == '\0') 77 return (-1); 78 79 if (!history_length || ((i >= history_length) && !reverse)) 80 return (-1); 81 82 if (reverse && (i >= history_length)) 83 i = history_length - 1; 84 85 #define NEXT_LINE() do { if (reverse) i--; else i++; } while (0) 86 87 the_history = history_list (); 88 string_len = strlen (string); 89 while (1) 90 { 91 /* Search each line in the history list for STRING. */ 92 93 /* At limit for direction? */ 94 if ((reverse && i < 0) || (!reverse && i == history_length)) 95 return (-1); 96 97 line = the_history[i]->line; 98 line_index = strlen (line); 99 100 /* If STRING is longer than line, no match. */ 101 if (string_len > line_index) 102 { 103 NEXT_LINE (); 104 continue; 105 } 106 107 /* Handle anchored searches first. */ 108 if (anchored == ANCHORED_SEARCH) 109 { 110 if (STREQN (string, line, string_len)) 111 { 112 history_offset = i; 113 return (0); 114 } 115 116 NEXT_LINE (); 117 continue; 118 } 119 120 /* Do substring search. */ 121 if (reverse) 122 { 123 line_index -= string_len; 124 125 while (line_index >= 0) 126 { 127 if (STREQN (string, line + line_index, string_len)) 128 { 129 history_offset = i; 130 return (line_index); 131 } 132 line_index--; 133 } 134 } 135 else 136 { 137 register int limit; 138 139 limit = line_index - string_len + 1; 140 line_index = 0; 141 142 while (line_index < limit) 143 { 144 if (STREQN (string, line + line_index, string_len)) 145 { 146 history_offset = i; 147 return (line_index); 148 } 149 line_index++; 150 } 151 } 152 NEXT_LINE (); 153 } 154 } 155 156 /* Do a non-anchored search for STRING through the history in DIRECTION. */ 157 int 158 history_search (string, direction) 159 const char *string; 160 int direction; 161 { 162 return (history_search_internal (string, direction, NON_ANCHORED_SEARCH)); 163 } 164 165 /* Do an anchored search for string through the history in DIRECTION. */ 166 int 167 history_search_prefix (string, direction) 168 const char *string; 169 int direction; 170 { 171 return (history_search_internal (string, direction, ANCHORED_SEARCH)); 172 } 173 174 /* Search for STRING in the history list. DIR is < 0 for searching 175 backwards. POS is an absolute index into the history list at 176 which point to begin searching. */ 177 int 178 history_search_pos (string, dir, pos) 179 const char *string; 180 int dir, pos; 181 { 182 int ret, old; 183 184 old = where_history (); 185 history_set_pos (pos); 186 if (history_search (string, dir) == -1) 187 { 188 history_set_pos (old); 189 return (-1); 190 } 191 ret = where_history (); 192 history_set_pos (old); 193 return ret; 194 } 195