1 | // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com) |
2 | // (C) Copyright 2005-2007 Jonathan Turkanis |
3 | // Distributed under the Boost Software License, Version 1.0. (See accompanying |
4 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.) |
5 | |
6 | // Adapted from an example of James Kanze. See |
7 | // https://web.archive.org/web/20041222094942/http://www.gabi-soft.fr/codebase-en.html. |
8 | |
9 | // See http://www.boost.org/libs/iostreams for documentation. |
10 | |
11 | #ifndef BOOST_IOSTREAMS_LINE_WRAPPING_FILTER_HPP_INCLUDED |
12 | #define BOOST_IOSTREAMS_LINE_WRAPPING_FILTER_HPP_INCLUDED |
13 | |
14 | #include <cstdio> // EOF. |
15 | #include <boost/iostreams/concepts.hpp> // output_filter. |
16 | #include <boost/iostreams/filter/stdio.hpp> |
17 | #include <boost/iostreams/operations.hpp> // boost::iostreams::put. |
18 | |
19 | namespace boost { namespace iostreams { namespace example { |
20 | |
21 | class line_wrapping_stdio_filter : public stdio_filter { |
22 | public: |
23 | explicit line_wrapping_stdio_filter(int line_length = 80) |
24 | : line_length_(line_length), col_no_(0) |
25 | { } |
26 | private: |
27 | void do_filter() |
28 | { |
29 | int c; |
30 | while ((c = std::cin.get()) != EOF) { |
31 | if (c != '\n' && col_no_ >= line_length_) |
32 | put_char(c: '\n'); |
33 | put_char(c); |
34 | } |
35 | } |
36 | void do_close() { col_no_ = 0; } |
37 | void put_char(int c) |
38 | { |
39 | std::cout.put(c: c); |
40 | if (c != '\n') |
41 | ++col_no_; |
42 | else |
43 | col_no_ = 0; |
44 | } |
45 | int line_length_; |
46 | int col_no_; |
47 | }; |
48 | |
49 | class line_wrapping_input_filter : public input_filter { |
50 | public: |
51 | explicit line_wrapping_input_filter(int line_length = 80) |
52 | : line_length_(line_length), col_no_(0), next_(0), has_next_(false) |
53 | { } |
54 | |
55 | template<typename Source> |
56 | int get(Source& src) |
57 | { |
58 | if (has_next_) { |
59 | has_next_ = false; |
60 | return get_char(c: next_); |
61 | } |
62 | |
63 | int c; |
64 | if ((c = iostreams::get(src)) == EOF || c == WOULD_BLOCK) |
65 | return c; |
66 | |
67 | if (c != '\n' && col_no_ >= line_length_) { |
68 | next_ = c; |
69 | has_next_ = true; |
70 | return get_char(c: '\n'); |
71 | } |
72 | |
73 | return get_char(c); |
74 | } |
75 | |
76 | template<typename Sink> |
77 | void close(Sink&) |
78 | { |
79 | col_no_ = 0; |
80 | has_next_ = false; |
81 | } |
82 | private: |
83 | int get_char(int c) |
84 | { |
85 | if (c != '\n') |
86 | ++col_no_; |
87 | else |
88 | col_no_ = 0; |
89 | return c; |
90 | } |
91 | int line_length_; |
92 | int col_no_; |
93 | int next_; |
94 | bool has_next_; |
95 | }; |
96 | |
97 | class line_wrapping_output_filter : public output_filter { |
98 | public: |
99 | explicit line_wrapping_output_filter(int line_length = 80) |
100 | : line_length_(line_length), col_no_(0) |
101 | { } |
102 | |
103 | template<typename Sink> |
104 | bool put(Sink& dest, int c) |
105 | { |
106 | if (c != '\n' && col_no_ >= line_length_ && !put_char(dest, '\n')) |
107 | return false; |
108 | return put_char(dest, c); |
109 | } |
110 | |
111 | template<typename Sink> |
112 | void close(Sink&) { col_no_ = 0; } |
113 | private: |
114 | template<typename Sink> |
115 | bool put_char(Sink& dest, int c) |
116 | { |
117 | if (!iostreams::put(dest, c)) |
118 | return false; |
119 | if (c != '\n') |
120 | ++col_no_; |
121 | else |
122 | col_no_ = 0; |
123 | return true; |
124 | } |
125 | int line_length_; |
126 | int col_no_; |
127 | }; |
128 | |
129 | } } } // End namespaces example, iostreams, boost. |
130 | |
131 | #endif // #ifndef BOOST_IOSTREAMS_LINE_WRAPPING_FILTER_HPP_INCLUDED |
132 | |