1 #ifndef history_h
2 #define history_h
3 
4 /*
5  * Copyright (c) 2000, 2001, 2002, 2003, 2004 by Martin C. Shepherd.
6  *
7  * All rights reserved.
8  *
9  * Permission is hereby granted, free of charge, to any person obtaining a
10  * copy of this software and associated documentation files (the
11  * "Software"), to deal in the Software without restriction, including
12  * without limitation the rights to use, copy, modify, merge, publish,
13  * distribute, and/or sell copies of the Software, and to permit persons
14  * to whom the Software is furnished to do so, provided that the above
15  * copyright notice(s) and this permission notice appear in all copies of
16  * the Software and that both the above copyright notice(s) and this
17  * permission notice appear in supporting documentation.
18  *
19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
22  * OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
23  * HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
24  * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
25  * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
26  * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
27  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
28  *
29  * Except as contained in this notice, the name of a copyright holder
30  * shall not be used in advertising or otherwise to promote the sale, use
31  * or other dealings in this Software without prior written authorization
32  * of the copyright holder.
33  */
34 
35 #include <stdio.h>    /* FILE * */
36 
37 /*-----------------------------------------------------------------------
38  * This module is used to record and traverse historical lines of user input.
39  */
40 
41 typedef struct GlHistory GlHistory;
42 
43 /*
44  * Create a new history maintenance object.
45  */
46 GlHistory *_new_GlHistory(size_t buflen);
47 
48 /*
49  * Delete a history maintenance object.
50  */
51 GlHistory *_del_GlHistory(GlHistory *glh);
52 
53 int _glh_add_history(GlHistory *glh, const char *line, int force);
54 
55 int _glh_search_prefix(GlHistory *glh, const char *line, int prefix_len);
56 
57 char *_glh_find_backwards(GlHistory *glh, char *line, size_t dim);
58 char *_glh_find_forwards(GlHistory *glh, char *line, size_t dim);
59 
60 int _glh_cancel_search(GlHistory *glh);
61 
62 char *_glh_oldest_line(GlHistory *glh, char *line, size_t dim);
63 char *_glh_current_line(GlHistory *glh, char *line, size_t dim);
64 
65 /*
66  * Whenever a new line is added to the history buffer, it is given
67  * a unique ID, recorded in an object of the following type.
68  */
69 typedef unsigned long GlhLineID;
70 
71 /*
72  * Query the id of a history line offset by a given number of lines from
73  * the one that is currently being recalled. If a recall session isn't
74  * in progress, or the offset points outside the history list, 0 is
75  * returned.
76  */
77 GlhLineID _glh_line_id(GlHistory *glh, int offset);
78 
79 /*
80  * Recall a line by its history buffer ID. If the line is no longer
81  * in the buffer, or the specified id is zero, NULL is returned.
82  */
83 char *_glh_recall_line(GlHistory *glh, GlhLineID id, char *line, size_t dim);
84 
85 /*
86  * Write the contents of the history buffer to a given file. Note that
87  * ~ and $ expansion are not performed on the filename.
88  */
89 int _glh_save_history(GlHistory *glh, const char *filename,
90 		      const char *comment, int max_lines);
91 
92 /*
93  * Restore the contents of the history buffer from a given file.
94  * Note that ~ and $ expansion are not performed on the filename.
95  */
96 int _glh_load_history(GlHistory *glh, const char *filename, const char *comment,
97 		      char *line, size_t dim);
98 
99 /*
100  * Set and query the current history group.
101  */
102 int _glh_set_group(GlHistory *glh, unsigned group);
103 int _glh_get_group(GlHistory *glh);
104 
105 /*
106  * Display the contents of the history list to the specified stdio
107  * output group.
108  */
109 int _glh_show_history(GlHistory *glh, GlWriteFn *write_fn, void *data,
110 		      const char *fmt, int all_groups, int max_lines);
111 
112 /*
113  * Change the size of the history buffer.
114  */
115 int _glh_resize_history(GlHistory *glh, size_t bufsize);
116 
117 /*
118  * Set an upper limit to the number of lines that can be recorded in the
119  * history list, or remove a previously specified limit.
120  */
121 void _glh_limit_history(GlHistory *glh, int max_lines);
122 
123 /*
124  * Discard either all history, or the history associated with the current
125  * history group.
126  */
127 void _glh_clear_history(GlHistory *glh, int all_groups);
128 
129 /*
130  * Temporarily enable or disable the history facility.
131  */
132 void _glh_toggle_history(GlHistory *glh, int enable);
133 
134 /*
135  * Lookup a history line by its sequential number of entry in the
136  * history buffer.
137  */
138 int _glh_lookup_history(GlHistory *glh, GlhLineID id, const char **line,
139 			unsigned *group, time_t *timestamp);
140 
141 /*
142  * Query the state of the history list.
143  */
144 void _glh_state_of_history(GlHistory *glh, int *enabled, unsigned *group,
145 			   int *max_lines);
146 
147 /*
148  * Get the range of lines in the history buffer.
149  */
150 void _glh_range_of_history(GlHistory *glh, unsigned long *oldest,
151 			   unsigned long *newest, int *nlines);
152 
153 /*
154  * Return the size of the history buffer and the amount of the
155  * buffer that is currently in use.
156  */
157 void _glh_size_of_history(GlHistory *glh, size_t *buff_size, size_t *buff_used);
158 
159 /*
160  * Get information about the last error in this module.
161  */
162 const char *_glh_last_error(GlHistory *glh);
163 
164 /*
165  * Return non-zero if a history search session is currently in progress.
166  */
167 int _glh_search_active(GlHistory *glh);
168 
169 #endif
170