检查std :: string是否是使用boost的有效uuid

Question

我想检查给定的字符串是否是使用boost的有效UUID.

这是我通过查看boost网站上的文档得出的:

void validate_uuid(const std::string& value)
{
    try
    {
        boost::uuids::string_generator stringGenerator;
        (void)stringGenerator(value);
    }

    catch (const std::exception& ex)
    {
        // ...
    }
}

但是,这并不总是有效.

如果我使用对于有效UUID而言太短的字符串调用该函数,则会按预期抛出异常.但是如果我用无效的UUID调用该函数(例如00000000-0000-0000-0000-00000000000K),则不会抛出任何异常.

有人可以澄清为什么会这样.

另外,我已经看到使用boost :: lexical_cast将字符串读取为此处发布的UUID .我想知道我是否应该采用这种方法.任何建议表示赞赏

Answer 1

您拥有的代码在验证方面没有任何作用。相反，它根据传递的常量生成一个 UUID（如哈希函数）。

仔细一看我错了。缺少的验证似乎是对版本的检查：

Live On Coliru

#include <boost/uuid/uuid.hpp>
#include <boost/uuid/uuid_io.hpp>
#include <boost/uuid/string_generator.hpp>
#include <iostream>

bool is_valid_uuid(std::string const& maybe_uuid, boost::uuids::uuid& result) {
    using namespace boost::uuids;

    try {
        result = string_generator()(maybe_uuid); 
        return result.version() != uuid::version_unknown;
    } catch(...) {
        return false;
    }
}

int main() {
    std::string maybe_uuid;
    std::cout << "Enter a UUID: ";

    while (std::cin >> maybe_uuid)
    {
        boost::uuids::uuid result;
        bool is_valid = is_valid_uuid(maybe_uuid, result);
        std::cout << "\n'" << maybe_uuid << "' valid: " << std::boolalpha << is_valid << "\n";

        if (is_valid)
            std::cout << "Parsed value: " << result << "\n";
    }
}

Coliruecho 00000000-0000-{0,4}000-0000-000000000000 $(uuidgen) "{$(uuidgen)}" | ./a.out的示例输出：：

Enter a UUID: 
'00000000-0000-0000-0000-000000000000' valid: false

'00000000-0000-4000-0000-000000000000' valid: true
Parsed value: 00000000-0000-4000-0000-000000000000

'a2c59f5c-6c9b-4800-afb8-282fc5e743cc' valid: true
Parsed value: a2c59f5c-6c9b-4800-afb8-282fc5e743cc

'{82a31d37-6fe4-4b80-b608-c63ec5ecd578}' valid: true
Parsed value: 82a31d37-6fe4-4b80-b608-c63ec5ecd578

Answer 2

这似乎更容易：

#include <boost/uuid/uuid.hpp>
#include <boost/uuid/uuid_io.hpp>
#include <iostream>
#include <sstream>

int main()
{
    std::string t1("01234567-89ab-cdef-0123-456789abcdef");
    std::string t2("Test UUID");

    boost::uuids::uuid u;
    std::istringstream iss(t1);
    iss >> u;
    if (iss.good())
        std::cerr << "'" << t1 << "' is a good UUID\n";
    else
        std::cerr << "'" << t1 << "' is not a good UUID\n";

    iss.str(t2);
    iss >> u;
    if (iss.good())
        std::cerr << "'" << t2 << "' is a good UUID\n";
    else
        std::cerr << "'" << t2 << "' is not a good UUID\n";

    return 0;
}

$ g++ -I/usr/local/include -std=c++11 test1.cpp
$ a.out
'01234567-89ab-cdef-0123-456789abcdef' is a good UUID
'Test UUID' is not a good UUID