1    	/* history.h -- the names of functions that you can call in history. */
2    	
3    	/* Copyright (C) 1989-2009 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   	#ifndef _HISTORY_H_
23   	#define _HISTORY_H_
24   	
25   	#ifdef __cplusplus
26   	extern "C" {
27   	#endif
28   	
29   	#include <time.h>		/* XXX - for history timestamp code */
30   	
31   	#if defined READLINE_LIBRARY
32   	#  include "rlstdc.h"
33   	#  include "rltypedefs.h"
34   	#else
35   	#  include <stdio.h>
36   	#  include <readline/rlstdc.h>
37   	#  include <readline/rltypedefs.h>
38   	#endif
39   	
40   	#ifdef __STDC__
41   	typedef void *histdata_t;
42   	#else
43   	typedef char *histdata_t;
44   	#endif
45   	
46   	/* The structure used to store a history entry. */
47   	typedef struct _hist_entry {
48   	  char *line;
49   	  char *timestamp;		/* char * rather than time_t for read/write */
50   	  histdata_t data;
51   	} HIST_ENTRY;
52   	
53   	/* Size of the history-library-managed space in history entry HS. */
54   	#define HISTENT_BYTES(hs)	(strlen ((hs)->line) + strlen ((hs)->timestamp))
55   	
56   	/* A structure used to pass the current state of the history stuff around. */
57   	typedef struct _hist_state {
58   	  HIST_ENTRY **entries;		/* Pointer to the entries themselves. */
59   	  int offset;			/* The location pointer within this array. */
60   	  int length;			/* Number of elements within this array. */
61   	  int size;			/* Number of slots allocated to this array. */
62   	  int flags;
63   	} HISTORY_STATE;
64   	
65   	/* Flag values for the `flags' member of HISTORY_STATE. */
66   	#define HS_STIFLED	0x01
67   	
68   	/* Initialization and state management. */
69   	
70   	/* Begin a session in which the history functions might be used.  This
71   	   just initializes the interactive variables. */
72   	extern void using_history PARAMS((void));
73   	
74   	/* Return the current HISTORY_STATE of the history. */
75   	extern HISTORY_STATE *history_get_history_state PARAMS((void));
76   	
77   	/* Set the state of the current history array to STATE. */
78   	extern void history_set_history_state PARAMS((HISTORY_STATE *));
79   	
80   	/* Manage the history list. */
81   	
82   	/* Place STRING at the end of the history list.
83   	   The associated data field (if any) is set to NULL. */
84   	extern void add_history PARAMS((const char *));
85   	
86   	/* Change the timestamp associated with the most recent history entry to
87   	   STRING. */
88   	extern void add_history_time PARAMS((const char *));
89   	
90   	/* A reasonably useless function, only here for completeness.  WHICH
91   	   is the magic number that tells us which element to delete.  The
92   	   elements are numbered from 0. */
93   	extern HIST_ENTRY *remove_history PARAMS((int));
94   	
95   	/* Free the history entry H and return any application-specific data
96   	   associated with it. */
97   	extern histdata_t free_history_entry PARAMS((HIST_ENTRY *));
98   	
99   	/* Make the history entry at WHICH have LINE and DATA.  This returns
100  	   the old entry so you can dispose of the data.  In the case of an
101  	   invalid WHICH, a NULL pointer is returned. */
102  	extern HIST_ENTRY *replace_history_entry PARAMS((int, const char *, histdata_t));
103  	
104  	/* Clear the history list and start over. */
105  	extern void clear_history PARAMS((void));
106  	
107  	/* Stifle the history list, remembering only MAX number of entries. */
108  	extern void stifle_history PARAMS((int));
109  	
110  	/* Stop stifling the history.  This returns the previous amount the
111  	   history was stifled by.  The value is positive if the history was
112  	   stifled, negative if it wasn't. */
113  	extern int unstifle_history PARAMS((void));
114  	
115  	/* Return 1 if the history is stifled, 0 if it is not. */
116  	extern int history_is_stifled PARAMS((void));
117  	
118  	/* Information about the history list. */
119  	
120  	/* Return a NULL terminated array of HIST_ENTRY which is the current input
121  	   history.  Element 0 of this list is the beginning of time.  If there
122  	   is no history, return NULL. */
123  	extern HIST_ENTRY **history_list PARAMS((void));
124  	
125  	/* Returns the number which says what history element we are now
126  	   looking at.  */
127  	extern int where_history PARAMS((void));
128  	  
129  	/* Return the history entry at the current position, as determined by
130  	   history_offset.  If there is no entry there, return a NULL pointer. */
131  	extern HIST_ENTRY *current_history PARAMS((void));
132  	
133  	/* Return the history entry which is logically at OFFSET in the history
134  	   array.  OFFSET is relative to history_base. */
135  	extern HIST_ENTRY *history_get PARAMS((int));
136  	
137  	/* Return the timestamp associated with the HIST_ENTRY * passed as an
138  	   argument */
139  	extern time_t history_get_time PARAMS((HIST_ENTRY *));
140  	
141  	/* Return the number of bytes that the primary history entries are using.
142  	   This just adds up the lengths of the_history->lines. */
143  	extern int history_total_bytes PARAMS((void));
144  	
145  	/* Moving around the history list. */
146  	
147  	/* Set the position in the history list to POS. */
148  	extern int history_set_pos PARAMS((int));
149  	
150  	/* Back up history_offset to the previous history entry, and return
151  	   a pointer to that entry.  If there is no previous entry, return
152  	   a NULL pointer. */
153  	extern HIST_ENTRY *previous_history PARAMS((void));
154  	
155  	/* Move history_offset forward to the next item in the input_history,
156  	   and return the a pointer to that entry.  If there is no next entry,
157  	   return a NULL pointer. */
158  	extern HIST_ENTRY *next_history PARAMS((void));
159  	
160  	/* Searching the history list. */
161  	
162  	/* Search the history for STRING, starting at history_offset.
163  	   If DIRECTION < 0, then the search is through previous entries,
164  	   else through subsequent.  If the string is found, then
165  	   current_history () is the history entry, and the value of this function
166  	   is the offset in the line of that history entry that the string was
167  	   found in.  Otherwise, nothing is changed, and a -1 is returned. */
168  	extern int history_search PARAMS((const char *, int));
169  	
170  	/* Search the history for STRING, starting at history_offset.
171  	   The search is anchored: matching lines must begin with string.
172  	   DIRECTION is as in history_search(). */
173  	extern int history_search_prefix PARAMS((const char *, int));
174  	
175  	/* Search for STRING in the history list, starting at POS, an
176  	   absolute index into the list.  DIR, if negative, says to search
177  	   backwards from POS, else forwards.
178  	   Returns the absolute index of the history element where STRING
179  	   was found, or -1 otherwise. */
180  	extern int history_search_pos PARAMS((const char *, int, int));
181  	
182  	/* Managing the history file. */
183  	
184  	/* Add the contents of FILENAME to the history list, a line at a time.
185  	   If FILENAME is NULL, then read from ~/.history.  Returns 0 if
186  	   successful, or errno if not. */
187  	extern int read_history PARAMS((const char *));
188  	
189  	/* Read a range of lines from FILENAME, adding them to the history list.
190  	   Start reading at the FROM'th line and end at the TO'th.  If FROM
191  	   is zero, start at the beginning.  If TO is less than FROM, read
192  	   until the end of the file.  If FILENAME is NULL, then read from
193  	   ~/.history.  Returns 0 if successful, or errno if not. */
194  	extern int read_history_range PARAMS((const char *, int, int));
195  	
196  	/* Write the current history to FILENAME.  If FILENAME is NULL,
197  	   then write the history list to ~/.history.  Values returned
198  	   are as in read_history ().  */
199  	extern int write_history PARAMS((const char *));
200  	
201  	/* Append NELEMENT entries to FILENAME.  The entries appended are from
202  	   the end of the list minus NELEMENTs up to the end of the list. */
203  	extern int append_history PARAMS((int, const char *));
204  	
205  	/* Truncate the history file, leaving only the last NLINES lines. */
206  	extern int history_truncate_file PARAMS((const char *, int));
207  	
208  	/* History expansion. */
209  	
210  	/* Expand the string STRING, placing the result into OUTPUT, a pointer
211  	   to a string.  Returns:
212  	
213  	   0) If no expansions took place (or, if the only change in
214  	      the text was the de-slashifying of the history expansion
215  	      character)
216  	   1) If expansions did take place
217  	  -1) If there was an error in expansion.
218  	   2) If the returned line should just be printed.
219  	
220  	  If an error occurred in expansion, then OUTPUT contains a descriptive
221  	  error message. */
222  	extern int history_expand PARAMS((char *, char **));
223  	
224  	/* Extract a string segment consisting of the FIRST through LAST
225  	   arguments present in STRING.  Arguments are broken up as in
226  	   the shell. */
227  	extern char *history_arg_extract PARAMS((int, int, const char *));
228  	
229  	/* Return the text of the history event beginning at the current
230  	   offset into STRING.  Pass STRING with *INDEX equal to the
231  	   history_expansion_char that begins this specification.
232  	   DELIMITING_QUOTE is a character that is allowed to end the string
233  	   specification for what to search for in addition to the normal
234  	   characters `:', ` ', `\t', `\n', and sometimes `?'. */
235  	extern char *get_history_event PARAMS((const char *, int *, int));
236  	
237  	/* Return an array of tokens, much as the shell might.  The tokens are
238  	   parsed out of STRING. */
239  	extern char **history_tokenize PARAMS((const char *));
240  	
241  	/* Exported history variables. */
242  	extern int history_base;
243  	extern int history_length;
244  	extern int history_max_entries;
245  	extern char history_expansion_char;
246  	extern char history_subst_char;
247  	extern char *history_word_delimiters;
248  	extern char history_comment_char;
249  	extern char *history_no_expand_chars;
250  	extern char *history_search_delimiter_chars;
251  	extern int history_quotes_inhibit_expansion;
252  	
253  	extern int history_write_timestamps;
254  	
255  	/* Backwards compatibility */
256  	extern int max_input_history;
257  	
258  	/* If set, this function is called to decide whether or not a particular
259  	   history expansion should be treated as a special case for the calling
260  	   application and not expanded. */
261  	extern rl_linebuf_func_t *history_inhibit_expansion_function;
262  	
263  	#ifdef __cplusplus
264  	}
265  	#endif
266  	
267  	#endif /* !_HISTORY_H_ */
268