C++ URLencode library详解编程语言

//If I read the quest correctly and you want to do this yourself, without using curl I think I have a solution (sssuming UTF-8) and I think this is a conformant and portable way of URL encoding query strings: 
#include <boost/function_output_iterator.hpp> 
#include <boost/bind.hpp> 
#include <algorithm> 
#include <sstream> 
#include <iostream> 
#include <iterator> 
#include <iomanip> 
namespace { 
std::string encimpl(std::string::value_type v) { 
if (isalnum(v)) 
return std::string()+v; 
std::ostringstream enc; 
enc << '%' << std::setw(2) << std::setfill('0') << std::hex << std::uppercase << int(static_cast<unsigned char>(v)); 
return enc.str(); 
} 
} 
std::string urlencode(const std::string& url) { 
// Find the start of the query string 
const std::string::const_iterator start = std::find(url.begin(), url.end(), '?'); 
// If there isn't one there's nothing to do! 
if (start == url.end()) 
return url; 
// store the modified query string 
std::string qstr; 
std::transform(start+1, url.end(), 
// Append the transform result to qstr 
boost::make_function_output_iterator(boost::bind(static_cast<std::string& (std::string::*)(const std::string&)>(&std::string::append),&qstr,_1)), 
encimpl); 
return std::string(url.begin(), start+1) + qstr; 
}

 
It has no non-standard dependencies other than boost and if you don't like the boost dependency it's not that hard to remove. 
I tested it using: 
int main() { 
const char *testurls[] = {"http://foo.com/bar?abc<>de??90   210fg!/"$%", 
"http://google.com", 
"http://www.unicode.com/example?großpösna"}; 
std::copy(testurls, &testurls[sizeof(testurls)/sizeof(*testurls)], 
std::ostream_iterator<std::string>(std::cout,"/n")); 
std::cout << "encode as: " << std::endl; 
std::transform(testurls, &testurls[sizeof(testurls)/sizeof(*testurls)], 
std::ostream_iterator<std::string>(std::cout,"/n"), 
std::ptr_fun(urlencode)); 
} 
Which all seemed to work: 
http://foo.com/bar?abc<>de??90   210fg!"$% 
http://google.com 
http://www.unicode.com/example?großpösna 
Becomes: 
http://foo.com/bar?abc%3C%3Ede%3F%3F90%20%20%20210fg%21%22%24%25 
http://google.com 
http://www.unicode.com/example?gro%C3%9Fp%C3%B6sna 
Which squares with these examples