ocean.io.console.readline.History source code

1 /*******************************************************************************
2 
3     A D wrapper around the GNU readline/history file
4 
5     The module contains functionalities to manipulate the readline session
6     history (e.g adding lines to the history so when the user would press the
7     up-arrow he would find the old lines).
8 
9     Notes:
10         - Requires linking with -lhistory
11         - The user of this module doesn't need to call `using_history()` as its
12           automatically called once this module is imported.
13 
14     Copyright:
15         Copyright (c) 2009-2016 dunnhumby Germany GmbH.
16         All rights reserved.
17 
18     License:
19         Boost Software License Version 1.0. See LICENSE_BOOST.txt for details.
20         Alternatively, this file may be distributed under the terms of the Tango
21         3-Clause BSD License (see LICENSE_BSD.txt for details).
22 
23         Bear in mind this module provides bindings to an external library that
24         has its own license, which might be more restrictive. Please check the
25         external library license to see which conditions apply for linking.
26 
27 *******************************************************************************/
28 
29 module ocean.io.console.readline.History;
30 
31 
32 import C = ocean.io.console.readline.c.history;
33 import ocean.text.util.StringC;
34 import ocean.meta.types.Qualifiers;
35 
36 static this()
37 {
38     // Required by readline to be called before starting the session.
39     // From readline documentation for using_history:
40     // "Begin a session in which the history functions might be used. This
41     // initializes the interactive variables."
42     C.using_history();
43 }
44 
45 /*******************************************************************************
46 
47     Add a line to the history of the readline
48 
49     Note:
50         If line isn't null-terminated then it's converted to a C null-terminated
51         string before passing it to the C add_history function.
52         Converting to C string might re-allocate the buffer. If you have tight
53         memory constraints, it is highly recommended to provide a null
54         terminated string or make sure that the GC block your buffer is stored
55         in has a spare byte at the end.
56 
57     Params:
58         line = the line to add to history
59 
60 *******************************************************************************/
61 
62 void addHistory(mstring line)
63 {
64     char* line_ptr = StringC.toCString( line );
65     C.add_history(line_ptr);
66 }