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1 | /******************************************************************************* |
2 | * $Revision$ | |
3 | * $Date$ | |
4 | * $Author$ | |
5 | * | |
6 | * Contents: A streambuf which uses the GNU readline library for line I/O | |
7 | * (c) 2001 by Dimitris Vyzovitis [vyzo@media.mit.edu] | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public | |
20 | * License along with this program; if not, write to the Free | |
21 | * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, | |
22 | * MA 02111-1307 USA | |
23 | * | |
24 | ******************************************************************************/ | |
25 | ||
26 | #ifndef _READLINEBUF_H_ | |
27 | #define _READLINEBUF_H_ | |
28 | ||
29 | #include <iostream> | |
30 | #include <cstring> | |
31 | #include <cassert> | |
32 | #include <cstdlib> | |
33 | #include <cstdio> | |
34 | ||
35 | #include <readline/readline.h> | |
36 | #include <readline/history.h> | |
37 | ||
38 | #if (defined __GNUC__) && (__GNUC__ < 3) | |
39 | #include <streambuf.h> | |
40 | #else | |
41 | #include <streambuf> | |
42 | using std::streamsize; | |
43 | using std::streambuf; | |
44 | #endif | |
45 | ||
46 | class readlinebuf : public streambuf { | |
47 | public: | |
48 | #if (defined __GNUC__) && (__GNUC__ < 3) | |
49 | typedef char char_type; | |
50 | typedef int int_type; | |
51 | typedef streampos pos_type; | |
52 | typedef streamoff off_type; | |
53 | #endif | |
54 | static const int_type eof = EOF; // this is -1 | |
55 | static const int_type not_eof = 0; | |
56 | ||
57 | private: | |
58 | const char* prompt_; | |
59 | bool history_; | |
60 | char* line_; | |
61 | int low_; | |
62 | int high_; | |
63 | ||
64 | protected: | |
65 | ||
66 | virtual int_type showmanyc() const { return high_ - low_; } | |
67 | ||
68 | virtual streamsize xsgetn( char_type* buf, streamsize n ) { | |
69 | int rd = n > (high_ - low_)? (high_ - low_) : n; | |
70 | memcpy( buf, line_, rd ); | |
71 | low_ += rd; | |
72 | ||
73 | if ( rd < n ) { | |
74 | low_ = high_ = 0; | |
75 | free( line_ ); // free( NULL ) is a noop | |
76 | line_ = readline( prompt_ ); | |
77 | if ( line_ ) { | |
78 | high_ = strlen( line_ ); | |
79 | if ( history_ && high_ ) add_history( line_ ); | |
80 | rd += xsgetn( buf + rd, n - rd ); | |
81 | } | |
82 | } | |
83 | ||
84 | return rd; | |
85 | } | |
86 | ||
87 | virtual int_type underflow() { | |
88 | if ( high_ == low_ ) { | |
89 | low_ = high_ = 0; | |
90 | free( line_ ); // free( NULL ) is a noop | |
91 | line_ = readline( prompt_ ); | |
92 | if ( line_ ) { | |
93 | high_ = strlen( line_ ); | |
94 | if ( history_ && high_ ) add_history( line_ ); | |
95 | } | |
96 | } | |
97 | ||
98 | if ( low_ < high_ ) return line_[low_]; | |
99 | else return eof; | |
100 | } | |
101 | ||
102 | virtual int_type uflow() { | |
103 | int_type c = underflow(); | |
104 | if ( c != eof ) ++low_; | |
105 | return c; | |
106 | } | |
107 | ||
108 | virtual int_type pbackfail( int_type c = eof ) { | |
109 | if ( low_ > 0 ) --low_; | |
110 | else if ( c != eof ) { | |
111 | if ( high_ > 0 ) { | |
112 | char* nl = (char*)realloc( line_, high_ + 1 ); | |
113 | if ( nl ) { | |
114 | line_ = (char*)memcpy( nl + 1, line_, high_ ); | |
115 | high_ += 1; | |
116 | line_[0] = char( c ); | |
117 | } else return eof; | |
118 | } else { | |
119 | assert( !line_ ); | |
120 | line_ = (char*)malloc( sizeof( char ) ); | |
121 | *line_ = char( c ); | |
122 | high_ = 1; | |
123 | } | |
124 | } else return eof; | |
125 | ||
126 | return not_eof; | |
127 | } | |
128 | ||
129 | public: | |
130 | readlinebuf( const char* prompt = NULL, bool history = true ) | |
131 | : prompt_( prompt ), history_( history ), | |
132 | line_( NULL ), low_( 0 ), high_( 0 ) { | |
133 | setbuf( 0, 0 ); | |
134 | } | |
135 | ||
136 | ||
137 | }; | |
138 | ||
139 | #endif |