1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
[/
Copyright 2006-2007 John Maddock.
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE_1_0.txt or copy at
http://www.boost.org/LICENSE_1_0.txt).
]
[section:regex_match regex_match]
#include <boost/regex.hpp>
The algorithm [regex_match] determines whether a given regular expression
matches [*all] of a given character sequence denoted by a pair of
bidirectional-iterators, the algorithm is defined as follows,
the main use of this function is data input validation.
[important Note that the result is true only if the expression matches the
*whole* of the input sequence. If you want to search for an
expression somewhere within the sequence then use [regex_search]. If you
want to match a prefix of the character string then use [regex_search]
with the flag match_continuous set.]
template <class BidirectionalIterator, class Allocator, class charT, class traits>
bool regex_match(BidirectionalIterator first, BidirectionalIterator last,
match_results<BidirectionalIterator, Allocator>& m,
const basic_regex <charT, traits>& e,
match_flag_type flags = match_default);
template <class BidirectionalIterator, class charT, class traits>
bool regex_match(BidirectionalIterator first, BidirectionalIterator last,
const basic_regex <charT, traits>& e,
match_flag_type flags = match_default);
template <class charT, class Allocator, class traits>
bool regex_match(const charT* str, match_results<const charT*, Allocator>& m,
const basic_regex <charT, traits>& e,
match_flag_type flags = match_default);
template <class ST, class SA, class Allocator, class charT, class traits>
bool regex_match(const basic_string<charT, ST, SA>& s,
match_results<typename basic_string<charT, ST, SA>::const_iterator, Allocator>& m,
const basic_regex <charT, traits>& e,
match_flag_type flags = match_default);
template <class charT, class traits>
bool regex_match(const charT* str,
const basic_regex <charT, traits>& e,
match_flag_type flags = match_default);
template <class ST, class SA, class charT, class traits>
bool regex_match(const basic_string<charT, ST, SA>& s,
const basic_regex <charT, traits>& e,
match_flag_type flags = match_default);
[h4 Description]
template <class BidirectionalIterator, class Allocator, class charT, class traits>
bool regex_match(BidirectionalIterator first, BidirectionalIterator last,
match_results<BidirectionalIterator, Allocator>& m,
const basic_regex <charT, traits>& e,
match_flag_type flags = match_default);
[*Requires]: Type BidirectionalIterator meets the requirements of a
Bidirectional Iterator (24.1.4).
[*Effects]: Determines whether there is an exact match between the regular expression /e/,
and all of the character sequence \[first, last), parameter /flags/
(see [match_flag_type]) is used to
control how the expression is matched against the character sequence.
Returns true if such a match exists, false otherwise.
[*Throws]: `std::runtime_error` if the complexity of matching the expression
against an N character string begins to exceed O(N[super 2]), or if the
program runs out of stack space while matching the expression (if Boost.Regex is
configured in recursive mode), or if the matcher exhausts its permitted
memory allocation (if Boost.Regex is configured in non-recursive mode).
[*Postconditions]: If the function returns false, then the effect on
parameter /m/ is undefined, otherwise the effects on parameter /m/ are
given in the table:
[table
[[Element][Value]]
[[`m.size()`][`e.mark_count()`]]
[[`m.empty()`][`false`]]
[[`m.prefix().first`][`first`]]
[[`m.prefix().last`][`first`]]
[[`m.prefix().matched`][`false`]]
[[`m.suffix().first`][`last`]]
[[`m.suffix().last`][`last`]]
[[`m.suffix().matched`][`false`]]
[[`m[0].first`][`first`]]
[[`m[0].second`][`last`]]
[[`m[0].matched`][true if a full match was found, and false if it was a
partial match (found as a result of the match_partial flag being set).]]
[[`m[n].first`][For all integers `n < m.size()`, the start of the sequence that
matched sub-expression /n/. Alternatively, if sub-expression /n/ did not
participate in the match, then `last`.]]
[[`m[n].second`][For all integers `n < m.size()`, the end of the sequence that
matched sub-expression /n/. Alternatively, if sub-expression /n/ did not
participate in the match, then `last`.]]
[[`m[n].matched`][For all integers `n < m.size()`, true if sub-expression /n/
participated in the match, false otherwise.]]
]
template <class BidirectionalIterator, class charT, class traits>
bool regex_match(BidirectionalIterator first, BidirectionalIterator last,
const basic_regex <charT, traits>& e,
match_flag_type flags = match_default);
[*Effects]: Behaves "as if" by constructing an instance of
`match_results<BidirectionalIterator> what`, and then returning the result of
`regex_match(first, last, what, e, flags)`.
template <class charT, class Allocator, class traits>
bool regex_match(const charT* str, match_results<const charT*, Allocator>& m,
const basic_regex <charT, traits>& e,
match_flag_type flags = match_default);
[*Effects]: Returns the result of `regex_match(str, str + char_traits<charT>::length(str), m, e, flags)`.
template <class ST, class SA, class Allocator,
class charT, class traits>
bool regex_match(const basic_string<charT, ST, SA>& s,
match_results<typename basic_string<charT, ST, SA>::const_iterator, Allocator>& m,
const basic_regex <charT, traits>& e,
match_flag_type flags = match_default);
[*Effects]: Returns the result of `regex_match(s.begin(), s.end(), m, e, flags)`.
template <class charT, class traits>
bool regex_match(const charT* str,
const basic_regex <charT, traits>& e,
match_flag_type flags = match_default);
[*Effects]: Returns the result of `regex_match(str, str + char_traits<charT>::length(str), e, flags)`.
template <class ST, class SA, class charT, class traits>
bool regex_match(const basic_string<charT, ST, SA>& s,
const basic_regex <charT, traits>& e,
match_flag_type flags = match_default);
[*Effects]: Returns the result of `regex_match(s.begin(), s.end(), e, flags)`.
[h4 Examples]
The following example processes an ftp response:
#include <stdlib.h>
#include <boost/regex.hpp>
#include <string>
#include <iostream>
using namespace boost;
regex expression("([0-9]+)(\\-| |$)(.*)");
// process_ftp:
// on success returns the ftp response code, and fills
// msg with the ftp response message.
int process_ftp(const char* response, std::string* msg)
{
cmatch what;
if(regex_match(response, what, expression))
{
// what[0] contains the whole string
// what[1] contains the response code
// what[2] contains the separator character
// what[3] contains the text message.
if(msg)
msg->assign(what[3].first, what[3].second);
return std::atoi(what[1].first);
}
// failure did not match
if(msg)
msg->erase();
return -1;
}
[endsect]
|
