1 /* History.h -- the names of functions that you can call in history. */
2 /* Copyright (C) 1989, 1992 Free Software Foundation, Inc.
3 
4    This file contains the GNU History Library (the Library), a set of
5    routines for managing the text of previously typed lines.
6 
7    The Library is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 2, or (at your option)
10    any later version.
11 
12    The Library is distributed in the hope that it will be useful, but
13    WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15    General Public License for more details.
16 
17    The GNU General Public License is often shipped with GNU software, and
18    is generally kept in a file called COPYING or LICENSE.  If you do not
19    have a copy of the license, write to the Free Software Foundation,
20    59 Temple Place, Suite 330, Boston, MA 02111 USA. */
21 
22 #ifndef _HISTORY_H_
23 #define _HISTORY_H_
24 
25 #ifdef __cplusplus
26 extern "C" {
27 #endif
28 
29 #if defined READLINE_LIBRARY
30 #  include "rlstdc.h"
31 #  include "rltypedefs.h"
32 #else
33 #  include <readline/rlstdc.h>
34 #  include <readline/rltypedefs.h>
35 #endif
36 
37 #ifdef __STDC__
38 typedef void *histdata_t;
39 #else
40 typedef char *histdata_t;
41 #endif
42 
43 /* The structure used to store a history entry. */
44 typedef struct _hist_entry {
45   char *line;
46   histdata_t data;
47 } HIST_ENTRY;
48 
49 /* A structure used to pass the current state of the history stuff around. */
50 typedef struct _hist_state {
51   HIST_ENTRY **entries;		/* Pointer to the entries themselves. */
52   int offset;			/* The location pointer within this array. */
53   int length;			/* Number of elements within this array. */
54   int size;			/* Number of slots allocated to this array. */
55   int flags;
56 } HISTORY_STATE;
57 
58 /* Flag values for the `flags' member of HISTORY_STATE. */
59 #define HS_STIFLED	0x01
60 
61 /* Initialization and state management. */
62 
63 /* Begin a session in which the history functions might be used.  This
64    just initializes the interactive variables. */
65 extern void using_history PARAMS((void));
66 
67 /* Return the current HISTORY_STATE of the history. */
68 extern HISTORY_STATE *history_get_history_state PARAMS((void));
69 
70 /* Set the state of the current history array to STATE. */
71 extern void history_set_history_state PARAMS((HISTORY_STATE *));
72 
73 /* Manage the history list. */
74 
75 /* Place STRING at the end of the history list.
76    The associated data field (if any) is set to NULL. */
77 extern void add_history PARAMS((const char *));
78 
79 /* A reasonably useless function, only here for completeness.  WHICH
80    is the magic number that tells us which element to delete.  The
81    elements are numbered from 0. */
82 extern HIST_ENTRY *remove_history PARAMS((int));
83 
84 /* Make the history entry at WHICH have LINE and DATA.  This returns
85    the old entry so you can dispose of the data.  In the case of an
86    invalid WHICH, a NULL pointer is returned. */
87 extern HIST_ENTRY *replace_history_entry PARAMS((int, const char *, histdata_t));
88 
89 /* Clear the history list and start over. */
90 extern void clear_history PARAMS((void));
91 
92 /* Stifle the history list, remembering only MAX number of entries. */
93 extern void stifle_history PARAMS((int));
94 
95 /* Stop stifling the history.  This returns the previous amount the
96    history was stifled by.  The value is positive if the history was
97    stifled, negative if it wasn't. */
98 extern int unstifle_history PARAMS((void));
99 
100 /* Return 1 if the history is stifled, 0 if it is not. */
101 extern int history_is_stifled PARAMS((void));
102 
103 /* Information about the history list. */
104 
105 /* Return a NULL terminated array of HIST_ENTRY which is the current input
106    history.  Element 0 of this list is the beginning of time.  If there
107    is no history, return NULL. */
108 extern HIST_ENTRY **history_list PARAMS((void));
109 
110 /* Returns the number which says what history element we are now
111    looking at.  */
112 extern int where_history PARAMS((void));
113 
114 /* Return the history entry at the current position, as determined by
115    history_offset.  If there is no entry there, return a NULL pointer. */
116 extern HIST_ENTRY *current_history PARAMS((void));
117 
118 /* Return the history entry which is logically at OFFSET in the history
119    array.  OFFSET is relative to history_base. */
120 extern HIST_ENTRY *history_get PARAMS((int));
121 
122 /* Return the number of bytes that the primary history entries are using.
123    This just adds up the lengths of the_history->lines. */
124 extern int history_total_bytes PARAMS((void));
125 
126 /* Moving around the history list. */
127 
128 /* Set the position in the history list to POS. */
129 extern int history_set_pos PARAMS((int));
130 
131 /* Back up history_offset to the previous history entry, and return
132    a pointer to that entry.  If there is no previous entry, return
133    a NULL pointer. */
134 extern HIST_ENTRY *previous_history PARAMS((void));
135 
136 /* Move history_offset forward to the next item in the input_history,
137    and return the a pointer to that entry.  If there is no next entry,
138    return a NULL pointer. */
139 extern HIST_ENTRY *next_history PARAMS((void));
140 
141 /* Searching the history list. */
142 
143 /* Search the history for STRING, starting at history_offset.
144    If DIRECTION < 0, then the search is through previous entries,
145    else through subsequent.  If the string is found, then
146    current_history () is the history entry, and the value of this function
147    is the offset in the line of that history entry that the string was
148    found in.  Otherwise, nothing is changed, and a -1 is returned. */
149 extern int history_search PARAMS((const char *, int));
150 
151 /* Search the history for STRING, starting at history_offset.
152    The search is anchored: matching lines must begin with string.
153    DIRECTION is as in history_search(). */
154 extern int history_search_prefix PARAMS((const char *, int));
155 
156 /* Search for STRING in the history list, starting at POS, an
157    absolute index into the list.  DIR, if negative, says to search
158    backwards from POS, else forwards.
159    Returns the absolute index of the history element where STRING
160    was found, or -1 otherwise. */
161 extern int history_search_pos PARAMS((const char *, int, int));
162 
163 /* Managing the history file. */
164 
165 /* Add the contents of FILENAME to the history list, a line at a time.
166    If FILENAME is NULL, then read from ~/.history.  Returns 0 if
167    successful, or errno if not. */
168 extern int read_history PARAMS((const char *));
169 
170 /* Read a range of lines from FILENAME, adding them to the history list.
171    Start reading at the FROM'th line and end at the TO'th.  If FROM
172    is zero, start at the beginning.  If TO is less than FROM, read
173    until the end of the file.  If FILENAME is NULL, then read from
174    ~/.history.  Returns 0 if successful, or errno if not. */
175 extern int read_history_range PARAMS((const char *, int, int));
176 
177 /* Write the current history to FILENAME.  If FILENAME is NULL,
178    then write the history list to ~/.history.  Values returned
179    are as in read_history ().  */
180 extern int write_history PARAMS((const char *));
181 
182 /* Append NELEMENT entries to FILENAME.  The entries appended are from
183    the end of the list minus NELEMENTs up to the end of the list. */
184 extern int append_history PARAMS((int, const char *));
185 
186 /* Truncate the history file, leaving only the last NLINES lines. */
187 extern int history_truncate_file PARAMS((const char *, int));
188 
189 /* History expansion. */
190 
191 /* Expand the string STRING, placing the result into OUTPUT, a pointer
192    to a string.  Returns:
193 
194    0) If no expansions took place (or, if the only change in
195       the text was the de-slashifying of the history expansion
196       character)
197    1) If expansions did take place
198   -1) If there was an error in expansion.
199    2) If the returned line should just be printed.
200 
201   If an error ocurred in expansion, then OUTPUT contains a descriptive
202   error message. */
203 extern int history_expand PARAMS((char *, char **));
204 
205 /* Extract a string segment consisting of the FIRST through LAST
206    arguments present in STRING.  Arguments are broken up as in
207    the shell. */
208 extern char *history_arg_extract PARAMS((int, int, const char *));
209 
210 /* Return the text of the history event beginning at the current
211    offset into STRING.  Pass STRING with *INDEX equal to the
212    history_expansion_char that begins this specification.
213    DELIMITING_QUOTE is a character that is allowed to end the string
214    specification for what to search for in addition to the normal
215    characters `:', ` ', `\t', `\n', and sometimes `?'. */
216 extern char *get_history_event PARAMS((const char *, int *, int));
217 
218 /* Return an array of tokens, much as the shell might.  The tokens are
219    parsed out of STRING. */
220 extern char **history_tokenize PARAMS((const char *));
221 
222 /* Exported history variables. */
223 extern int history_base;
224 extern int history_length;
225 extern int history_max_entries;
226 extern char history_expansion_char;
227 extern char history_subst_char;
228 extern char *history_word_delimiters;
229 extern char history_comment_char;
230 extern char *history_no_expand_chars;
231 extern char *history_search_delimiter_chars;
232 extern int history_quotes_inhibit_expansion;
233 
234 /* Backwards compatibility */
235 extern int max_input_history;
236 
237 /* If set, this function is called to decide whether or not a particular
238    history expansion should be treated as a special case for the calling
239    application and not expanded. */
240 extern rl_linebuf_func_t *history_inhibit_expansion_function;
241 
242 #ifdef __cplusplus
243 }
244 #endif
245 
246 #endif /* !_HISTORY_H_ */
247