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
26extern "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__
38typedef void *histdata_t;
39#else
40typedef char *histdata_t;
41#endif
42
43/* The structure used to store a history entry. */
44typedef 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. */
50typedef 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. */
65extern void using_history PARAMS((void));
66
67/* Return the current HISTORY_STATE of the history. */
68extern HISTORY_STATE *history_get_history_state PARAMS((void));
69
70/* Set the state of the current history array to STATE. */
71extern 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. */
77extern 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. */
82extern 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. */
87extern HIST_ENTRY *replace_history_entry PARAMS((int, const char *, histdata_t));
88
89/* Clear the history list and start over. */
90extern void clear_history PARAMS((void));
91
92/* Stifle the history list, remembering only MAX number of entries. */
93extern 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. */
98extern int unstifle_history PARAMS((void));
99
100/* Return 1 if the history is stifled, 0 if it is not. */
101extern 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. */
108extern HIST_ENTRY **history_list PARAMS((void));
109
110/* Returns the number which says what history element we are now
111   looking at.  */
112extern 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. */
116extern 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. */
120extern 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. */
124extern int history_total_bytes PARAMS((void));
125
126/* Moving around the history list. */
127
128/* Set the position in the history list to POS. */
129extern 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. */
134extern 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. */
139extern 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. */
149extern 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(). */
154extern 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. */
161extern 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. */
168extern 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. */
175extern 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 ().  */
180extern 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. */
184extern int append_history PARAMS((int, const char *));
185
186/* Truncate the history file, leaving only the last NLINES lines. */
187extern 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. */
203extern 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. */
208extern 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 `?'. */
216extern 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. */
220extern char **history_tokenize PARAMS((const char *));
221
222/* Exported history variables. */
223extern int history_base;
224extern int history_length;
225extern int history_max_entries;
226extern char history_expansion_char;
227extern char history_subst_char;
228extern char *history_word_delimiters;
229extern char history_comment_char;
230extern char *history_no_expand_chars;
231extern char *history_search_delimiter_chars;
232extern int history_quotes_inhibit_expansion;
233
234/* Backwards compatibility */
235extern 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. */
240extern rl_linebuf_func_t *history_inhibit_expansion_function;
241
242#ifdef __cplusplus
243}
244#endif
245
246#endif /* !_HISTORY_H_ */
247