code_snippet
[TOC]
[CPP] 读取文件
static bool ReadFile(const char *file, std::string &out)
{
std::ifstream fin(file);
if (!fin.is_open())
{
return false;
}
std::stringstream buffer;
buffer << fin.rdbuf();
out.assign(buffer.str());
fin.close();
return true;
}[C/CPP] 切分字符串
利用 std::string 的成员方法实现
根据指定的分割字符串切分目标字符串，支持忽略空字符串、去除前后空白字符
#include <string>
#include <iostream>
#include <vector>
std::vector<std::string> Split(
const std::string &str,
const std::string &delimiter,
const bool allow_empty,
const bool trim_whitespaces
)
{
// 切分字符串
std::vector<std::string> vec;
if (delimiter.empty())
{
return vec;
}
std::size_t current = 0;
std::size_t index = 0;
while ((index = str.find(delimiter, current)) != str.npos)
{
if (index - current != 0 || allow_empty)
{
vec.emplace_back(str.substr(current, index - current));
}
current = index + delimiter.length();
}
if (current < str.length() || allow_empty)
{
vec.emplace_back(str.substr(current));
}
if (!trim_whitespaces)
{
return vec;
}
// 去除前后空白字符
std::string raw;
std::size_t beg = 0;
std::size_t end = 0;
std::vector<std::string> vec2;
for (auto v : vec)
{
if ((beg = v.find_first_not_of(" \t\f\v\n\r")) != raw.npos
&& (end = v.find_last_not_of(" \t\f\v\n\r"), beg) != raw.npos)
{
vec2.push_back(v.substr(beg, end - beg + 1));
}
}
return vec2;
}
int main()
{
std::string target = "hello, world , a b c , ,,kevin's blog ,";
std::vector<std::string> result = Split(target, ",", false, true);
for (auto v : result)
{
std::cout << v << std::endl;
}
return 0;
}输出
hello
world
a b c
kevin's blog利用 std::stringstream 实现
**限制：**分隔符为一个或多个空格
#include <sstream>
#include <string>
#include <iostream>
int main()
{
std::string input = "hello glad to see you ";
std::stringstream ss(input);
std::string str;
while (ss >> str)
{
std::cout << str << std::endl;
}
return 0;
}输出
hello
glad
to
see
you利用 strtok/strtok_r 实现
源码路径：split.c
**是否线程安全：**strtok 在提取字符串时使用了静态缓冲区，非线程安全；strtok_r 线程安全
#include <stdio.h>
#include <string.h>
// char *strtok(char *str, const char *delim);
// char *strtok_r(char *str, const char *delim, char **saveptr);
void Split()
{
char str[] = "1, hello, world";
char *ptr = strtok(str, ",");
while (ptr != NULL)
{
printf("%s\n", ptr);
ptr = strtok(NULL, ",");
}
}
void Split2()
{
char str[] = "2, hello, world";
char *buf = NULL;
char *ptr = strtok_r(str, ",", &buf);
while (ptr != NULL)
{
printf("%s\n", ptr);
ptr = strtok_r(NULL, ",", &buf);
}
}
int main()
{
Split();
Split2();
return 0;
}输出
1
hello
world
2
hello
world[CPP] 递增序列/随机序列
利用 std::itoa 实现 list/vector 自增序列
利用 std::shuffle 实现随机序列
#include <algorithm>
#include <iostream>
#include <list>
#include <numeric>
#include <random>
#include <vector>
int main()
{
std::vector<int> vec(10);
std::iota(vec.begin(), vec.end(), 1);
std::cout << "Contents of the vector: ";
for (auto n : vec) std::cout << n << ' ';
std::cout << '\n';
std::list<int> l(10);
std::iota(l.begin(), l.end(), -4);
std::vector<std::list<int>::iterator> v(l.size());
std::iota(v.begin(), v.end(), l.begin());
std::shuffle(v.begin(), v.end(), std::mt19937{ std::random_device{}() });
std::cout << "Contents of the list: ";
for (auto n : l) std::cout << n << ' ';
std::cout << '\n';
std::cout << "Contents of the list, shuffled: ";
for (auto i : v) std::cout << *i << ' ';
std::cout << '\n';
return 0;
}输出
Contents of the vector: 1 2 3 4 5 6 7 8 9 10
Contents of the list: -4 -3 -2 -1 0 1 2 3 4 5
Contents of the list, shuffled: -3 3 5 1 4 0 -2 2 -4 -1std::itoa 模拟实现
template<class ForwardIterator, class T>
void iota(ForwardIterator first, ForwardIterator last, T value)
{
while (first != last)
{
*first++ = value;
++value;
}
}[CPP] 处理信号，服务优雅退出
#include <chrono>
#include <signal.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
static bool g_done = false;
static void SignalHandler(int)
{
std::cout << "[WARN] try to stop and exit" << std::endl;
g_done = true;
}
static void RegisterSignalHandler(void)
{
struct sigaction action;
action.sa_handler = SignalHandler;
sigemptyset(&action.sa_mask);
// Handle signals properly before shutting down the server.
// Ctrl + C
sigaction(SIGINT, &action, (struct sigaction *)nullptr);
// kill PID
sigaction(SIGTERM, &action, (struct sigaction *)nullptr);
}
int main(int argc, char **argv)
{
RegisterSignalHandler();
// start service
while (!g_done)
{
std::this_thread::sleep_for(std::chrono::seconds(1));
}
// stop service
return 0;
}[CPP] 自定义服务运行参数
static void ShowHelp()
{
const char *help =
"=============================================\n"
" Desc: Danbay's Access Service\n"
"\n"
" Usage:\n"
" -c/--conf <file> default 'default.conf'\n"
" -d/--daemon run in daemon mode\n"
" -w/--watchdog run with watchdog\n"
" -h/--help show help and exit\n"
"=============================================\n";
std::cout << help << std::endl;
}
int main(int argc, char **argv)
{
const char *conf = "default.conf";
bool daemon_alias = false;
bool watchdog = false;
const struct option options[] = {
{"conf", 1, nullptr, 'c'},
{"daemon", 0, nullptr, 'd'},
{"watchdog", 0, nullptr, 'w'},
{"help", 0, nullptr, 'h'}
};
int opt = -1;
while ((opt = getopt_long(argc, argv, "c:dwh", options, nullptr)) != -1)
{
switch (opt)
{
case 'c':
conf = optarg;
break;
case 'd':
daemon_alias = true;
break;
case 'w':
watchdog = true;
break;
case 'h':
default:
ShowHelp();
return -1;
}
}
// RegisterSignalHandler();
std::string config;
if (!ReadFile(conf, config))
{
std::cerr << "[ERROR] open conf file failed" << std::endl;
return -1;
}
std::cout << "[INFO] here is all configuration information" <<
std::endl << config << std::endl;
int ret = 0;
if (daemon_alias)
{
int nochdir = 1;
int noclose = 0;
ret = daemon(nochdir, noclose);
if (ret == -1)
{
std::cerr << "[ERROR] run in daemon mode failed" << std::endl;
return -1;
}
}
while (watchdog)
{
ret = fork();
if (ret == -1)
{
std::cerr << "[ERROR] run with watchdog failed" << std::endl;
return -1;
}
else if (ret == 0)
{
break;
}
if (wait(&ret) == -1)
{
std::cerr << "[ERROR] run with watchdog failed" << std::endl;
return -1;
}
}
// ...
}[CPP] SSL/TLS 客户端
源码路径：
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <resolv.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#define MAXBUF 1024
#define CA_FILE "ca.pem"
#define CLIENT_KEY "client.pem"
#define CLIENT_CERT "client.pem"
void ShowCerts(SSL * ssl)
{
X509 *cert;
char *line;
cert = SSL_get_peer_certificate(ssl);
if (cert != NULL)
{
line = X509_NAME_oneline(X509_get_subject_name(cert), 0, 0);
printf("证书: %s\n", line);
free(line);
line = X509_NAME_oneline(X509_get_issuer_name(cert), 0, 0);
printf("颁发者: %s\n", line);
free(line);
X509_free(cert);
}
else
{
printf("无证书信息！\n");
}
}
int main(int argc, char **argv)
{
int sockfd, len;
struct sockaddr_in dest;
char buffer[MAXBUF + 1];
SSL_CTX *ctx;
SSL *ssl;
const SSL_METHOD *method;
if (argc != 3)
{
printf("%s <ip> <port>\n", argv[0]);
exit(0);
}
SSL_library_init();
SSL_load_error_strings();
OpenSSL_add_all_algorithms();
method = TLSv1_2_client_method();
ctx = SSL_CTX_new(method);
if (!ctx)
{
printf("create ctx is failed.\n");
}
/* 设置会话的握手方式 */
SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, 0);
/* 加载 CA FILE */
if (SSL_CTX_load_verify_locations(ctx, CA_FILE, 0) != 1)
{
SSL_CTX_free(ctx);
printf("Failed to load CA file %s", CA_FILE);
}
if (SSL_CTX_set_default_verify_paths(ctx) != 1)
{
SSL_CTX_free(ctx);
printf("Call to SSL_CTX_set_default_verify_paths failed");
}
/* 加载客户端证书 */
if (SSL_CTX_use_certificate_file(ctx, CLIENT_CERT, SSL_FILETYPE_PEM) != 1)
{
SSL_CTX_free(ctx);
printf("Failed to load client certificate from %s", CLIENT_KEY);
}
/* 加载客户端私钥 */
if (SSL_CTX_use_PrivateKey_file(ctx, CLIENT_KEY, SSL_FILETYPE_PEM) != 1)
{
SSL_CTX_free(ctx);
printf("Failed to load client private key from %s", CLIENT_KEY);
}
/* 验证私钥 */
if (SSL_CTX_check_private_key(ctx) != 1)
{
SSL_CTX_free(ctx);
printf("SSL_CTX_check_private_key failed");
}
/* 处理握手多次 */
SSL_CTX_set_mode(ctx, SSL_MODE_AUTO_RETRY);
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
{
perror("Create socket error.\n");
exit(errno);
}
bzero(&dest, sizeof(dest));
dest.sin_family = AF_INET;
dest.sin_port = htons(atoi(argv[2]));
if (inet_aton(argv[1], (struct in_addr *)&dest.sin_addr.s_addr) == 0)
{
perror(argv[1]);
exit(errno);
}
if (connect(sockfd, (struct sockaddr *)&dest, sizeof(dest)) != 0)
{
perror("Connect error.\n");
exit(errno);
}
/* 创建 SSL */
ssl = SSL_new(ctx);
if (ssl == NULL)
{
printf("SSL_new error.\n");
}
/* 将 fd 添加到 ssl 层 */
SSL_set_fd(ssl, sockfd);
if (SSL_connect(ssl) == -1)
{
printf("SSL_connect fail.\n");
ERR_print_errors_fp(stderr);
}
else
{
printf("SSL 最终协商的算法：%s\n", SSL_get_cipher(ssl));
ShowCerts(ssl);
}
bzero(buffer, MAXBUF + 1);
strcpy(buffer, "Hello World!");
len = SSL_write(ssl, buffer, strlen(buffer));
if (len < 0)
{
printf("消息'%s'发送失败，错误码：%d，错误信息：'%s'\n",
buffer, errno, strerror(errno));
goto finish;
}
else
{
printf("消息'%s'发送成功，长度：%d 字节\n", buffer, len);
}
bzero(buffer, MAXBUF + 1);
len = SSL_read(ssl, buffer, MAXBUF);
if (len > 0)
{
printf("接收消息成功: '%s'，长度：%d\n", buffer, len);
}
else
{
printf("接收消息失败，错误码：%d，错误信息：'%s'\n",
errno, strerror(errno));
}
finish:
SSL_shutdown(ssl);
SSL_free(ssl);
close(sockfd);
SSL_CTX_free(ctx);
return 0;
}#include <cstdlib>
#include <iostream>
#include <boost/bind.hpp>
#include <boost/asio.hpp>
#include <boost/asio/ssl.hpp>
enum { max_length = 1024 };
class client
{
public:
client(boost::asio::io_service& io_service,
boost::asio::ssl::context& context,
boost::asio::ip::tcp::resolver::iterator endpoint_iterator)
: socket_(io_service, context)
{
socket_.set_verify_mode(boost::asio::ssl::verify_peer);
socket_.set_verify_callback(
boost::bind(&client::verify_certificate, this, _1, _2));
boost::asio::async_connect(socket_.lowest_layer(), endpoint_iterator,
boost::bind(&client::handle_connect, this,
boost::asio::placeholders::error));
}
bool verify_certificate(bool preverified,
boost::asio::ssl::verify_context& ctx)
{
// The verify callback can be used to check whether the certificate that is
// being presented is valid for the peer. For example, RFC 2818 describes
// the steps involved in doing this for HTTPS. Consult the OpenSSL
// documentation for more details. Note that the callback is called once
// for each certificate in the certificate chain, starting from the root
// certificate authority.
// In this example we will simply print the certificate's subject name.
char subject_name[256];
X509* cert = X509_STORE_CTX_get_current_cert(ctx.native_handle());
X509_NAME_oneline(X509_get_subject_name(cert), subject_name, 256);
std::cout << "Verifying " << subject_name << "\n";
return preverified;
}
void handle_connect(const boost::system::error_code& error)
{
if (!error)
{
socket_.async_handshake(boost::asio::ssl::stream_base::client,
boost::bind(&client::handle_handshake, this,
boost::asio::placeholders::error));
}
else
{
std::cout << "Connect failed: " << error.message() << "\n";
}
}
void handle_handshake(const boost::system::error_code& error)
{
if (!error)
{
std::cout << "Enter message: ";
std::cin.getline(request_, max_length);
size_t request_length = strlen(request_);
boost::asio::async_write(socket_,
boost::asio::buffer(request_, request_length),
boost::bind(&client::handle_write, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
else
{
std::cout << "Handshake failed: " << error.message() << "\n";
}
}
void handle_write(const boost::system::error_code& error,
size_t bytes_transferred)
{
if (!error)
{
boost::asio::async_read(socket_,
boost::asio::buffer(reply_, bytes_transferred),
boost::bind(&client::handle_read, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
else
{
std::cout << "Write failed: " << error.message() << "\n";
}
}
void handle_read(const boost::system::error_code& error,
size_t bytes_transferred)
{
if (!error)
{
std::cout << "Reply: ";
std::cout.write(reply_, bytes_transferred);
std::cout << "\n";
}
else
{
std::cout << "Read failed: " << error.message() << "\n";
}
}
private:
boost::asio::ssl::stream<boost::asio::ip::tcp::socket> socket_;
char request_[max_length];
char reply_[max_length];
};
std::string get_password()
{
return "Danbay666!";
}
int main(int argc, char* argv[])
{
try
{
if (argc != 3)
{
std::cerr << "Usage: client <host> <port>\n";
return 1;
}
boost::asio::io_service io_service;
boost::asio::ip::tcp::resolver resolver(io_service);
boost::asio::ip::tcp::resolver::query query(argv[1], argv[2]);
boost::asio::ip::tcp::resolver::iterator iterator = resolver.resolve(query);
boost::asio::ssl::context ctx(boost::asio::ssl::context::sslv23);
ctx.set_password_callback(boost::bind(&get_password));
ctx.use_certificate_chain_file("client.pem");
ctx.use_private_key_file("client.pem", boost::asio::ssl::context::pem);
ctx.load_verify_file("ca.pem");
client c(io_service, ctx, iterator);
io_service.run();
}
catch (std::exception& e)
{
std::cerr << "Exception: " << e.what() << "\n";
}
return 0;
}[CPP] SSL/TLS 服务器端
源码路径：boost_ssl_server.cpp
#include <cstdlib>
#include <iostream>
#include <boost/bind.hpp>
#include <boost/asio.hpp>
#include <boost/asio/ssl.hpp>
typedef boost::asio::ssl::stream<boost::asio::ip::tcp::socket> ssl_socket;
class session
{
public:
session(boost::asio::io_service& io_service,
boost::asio::ssl::context& context)
: socket_(io_service, context)
{
}
ssl_socket::lowest_layer_type& socket()
{
return socket_.lowest_layer();
}
void start()
{
socket_.async_handshake(boost::asio::ssl::stream_base::server,
boost::bind(&session::handle_handshake, this,
boost::asio::placeholders::error));
}
void handle_handshake(const boost::system::error_code& error)
{
if (!error)
{
socket_.async_read_some(boost::asio::buffer(data_, max_length),
boost::bind(&session::handle_read, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
else
{
delete this;
}
}
void handle_read(const boost::system::error_code& error,
size_t bytes_transferred)
{
if (!error)
{
boost::asio::async_write(socket_,
boost::asio::buffer(data_, bytes_transferred),
boost::bind(&session::handle_write, this,
boost::asio::placeholders::error));
}
else
{
delete this;
}
}
void handle_write(const boost::system::error_code& error)
{
if (!error)
{
socket_.async_read_some(boost::asio::buffer(data_, max_length),
boost::bind(&session::handle_read, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
else
{
delete this;
}
}
private:
ssl_socket socket_;
enum { max_length = 1024 };
char data_[max_length];
};
class server
{
public:
server(boost::asio::io_service& io_service, unsigned short port)
: io_service_(io_service),
acceptor_(io_service,
boost::asio::ip::tcp::endpoint(boost::asio::ip::tcp::v4(), port)),
context_(boost::asio::ssl::context::sslv23)
{
context_.set_options(
boost::asio::ssl::context::default_workarounds
| boost::asio::ssl::context::no_sslv2
| boost::asio::ssl::context::single_dh_use);
context_.set_password_callback(boost::bind(&server::get_password, this));
context_.set_verify_callback(boost::bind(&server::verify_certificate, this, _1, _2));
context_.use_certificate_chain_file("server.pem");
context_.use_private_key_file("server.pem", boost::asio::ssl::context::pem);
context_.load_verify_file("ca.pem");
context_.set_verify_mode(boost::asio::ssl::verify_peer);
start_accept();
}
bool verify_certificate(bool preverified,
boost::asio::ssl::verify_context& ctx)
{
// The verify callback can be used to check whether the certificate that is
// being presented is valid for the peer. For example, RFC 2818 describes
// the steps involved in doing this for HTTPS. Consult the OpenSSL
// documentation for more details. Note that the callback is called once
// for each certificate in the certificate chain, starting from the root
// certificate authority.
// In this example we will simply print the certificate's subject name.
char subject_name[256];
X509* cert = X509_STORE_CTX_get_current_cert(ctx.native_handle());
X509_NAME_oneline(X509_get_subject_name(cert), subject_name, 256);
std::cout << "Verifying " << subject_name << "\n";
return preverified;
}
std::string get_password() const
{
return "Danbay666!";
}
void start_accept()
{
session* new_session = new session(io_service_, context_);
acceptor_.async_accept(new_session->socket(),
boost::bind(&server::handle_accept, this, new_session,
boost::asio::placeholders::error));
}
void handle_accept(session* new_session,
const boost::system::error_code& error)
{
if (!error)
{
new_session->start();
}
else
{
delete new_session;
}
start_accept();
}
private:
boost::asio::io_service& io_service_;
boost::asio::ip::tcp::acceptor acceptor_;
boost::asio::ssl::context context_;
};
int main(int argc, char* argv[])
{
try
{
if (argc != 2)
{
std::cerr << "Usage: server <port>\n";
return 1;
}
boost::asio::io_service io_service;
using namespace std; // For atoi.
server s(io_service, atoi(argv[1]));
io_service.run();
}
catch (std::exception& e)
{
std::cerr << "Exception: " << e.what() << "\n";
}
return 0;
}[CPP] protobuf 反射
**参考资料：**https://github.com/chenshuo/recipes
#include <google/protobuf/descriptor.h>
#include <google/protobuf/message.h>
#include <string>
#include <arpa/inet.h> // htonl, ntohl
#include <stdint.h>
// struct ProtobufTransportFormat __attribute__ ((__packed__))
// {
// int32_t len;
// int32_t nameLen;
// char typeName[nameLen];
// char protobufData[len-nameLen-4];
// }
const int32_t kHeaderLen = sizeof(int32_t);
///
/// Encode protobuf Message to transport format defined above
/// returns a std::string.
///
/// returns a empty string if message.AppendToString() fails.
///
inline std::string Encode(const google::protobuf::Message& message)
{
std::string result;
result.resize(kHeaderLen);
const std::string& typeName = message.GetTypeName();
int32_t nameLen = static_cast<int32_t>(typeName.size() + 1);
int32_t be32 = ::htonl(nameLen);
result.append(reinterpret_cast<char*>(&be32), sizeof(be32));
result.append(typeName.c_str(), nameLen);
bool succeed = message.AppendToString(&result);
if (succeed)
{
int32_t len = ::htonl(result.size() - kHeaderLen);
std::copy(reinterpret_cast<char*>(&len),
reinterpret_cast<char*>(&len) + sizeof(len),
result.begin());
}
else
{
result.clear();
}
return result;
}
inline google::protobuf::Message* CreateMessage(const std::string& type_name)
{
google::protobuf::Message* message = nullptr;
const google::protobuf::Descriptor* descriptor =
google::protobuf::DescriptorPool::generated_pool()->FindMessageTypeByName(type_name);
if (descriptor)
{
const google::protobuf::Message* prototype =
google::protobuf::MessageFactory::generated_factory()->GetPrototype(descriptor);
if (prototype)
{
message = prototype->New();
}
}
return message;
}
inline int32_t AsInt32(const char* buf)
{
int32_t be32 = 0;
::memcpy(&be32, buf, sizeof(be32));
return ::ntohl(be32);
}
///
/// Decode protobuf Message from transport format defined above.
/// returns a Message*
///
/// returns nullptr if fails.
///
inline google::protobuf::Message* Decode(const std::string& buf)
{
google::protobuf::Message* result = nullptr;
// len(4) + nameLen(4) + typeName(2)
assert(buf.size() >= (2 * kHeaderLen + 2));
int32_t len = AsInt32(buf.c_str());
assert(len == static_cast<int32_t>(buf.size() - kHeaderLen));
int32_t nameLen = AsInt32(buf.c_str() + kHeaderLen);
if (nameLen >= 2)
{
std::string typeName(buf.begin() + 2 * kHeaderLen,
buf.begin() + 2 * kHeaderLen + nameLen - 1);
google::protobuf::Message* message = CreateMessage(typeName);
if (message)
{
const char* data = buf.c_str() + 2 * kHeaderLen + nameLen;
int32_t dataLen = buf.size() - 2 * kHeaderLen - nameLen;
if (message->ParseFromArray(data, dataLen))
{
result = message;
}
else
{
// parse error
delete message;
}
}
else
{
// unknown message type
}
}
else
{
// invalid name len
}
return result;
}
int main()
{
ClientInfoReq client_info;
client_info.set_user_type(2);
client_info.set_client_id(1101);
client_info.set_enroll_date("2018-06-01 14:22:39");
client_info.set_client_name("Jack");
std::string data = Encode(client_info);
google::protobuf::Message *message = Decode(data);
if (dynamic_cast<ClientInfoReq *>(message))
{
std::cout << "succeed to call decode" << std::endl;
}
delete client_info2;
}[CPP] 字符串十六进制转换
源码路径：hex_str.cpp
#include <iostream>
#include <string>
#include <cstdint>
#include <cassert>
const int8_t HexDigitTable[256] = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, -1, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0xa, 0xb, 0xc, 0xd, 0xe,
0xf, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, };
const int8_t HexTable[] = "0123456789abcdef";
std::string Str2Hex(std::string src)
{
std::string dst;
dst.reserve(src.size() * 2);
for (auto itor : src)
{
dst.push_back(HexTable[itor >> 4]);
dst.push_back(HexTable[itor & 0x0f]);
}
return dst;
}
std::string Hex2Str(std::string src)
{
assert(src.size() % 2 == 0);
std::string dst;
int8_t c;
dst.reserve(src.size() / 2);
for (auto itor = src.begin(); itor != src.end(); ++ itor)
{
c = (HexDigitTable[*itor++] << 4) | HexDigitTable[*itor];
dst.push_back(c);
}
return dst;
}
int main()
{
std::string src = "hello world";
std::string dst = Str2Hex(src);
std::cout << dst << std::endl;
std::cout << Hex2Str(dst) << std::endl;
return 0;
}输出
68656c6c6f20776f726c64
hello world[CPP] find sub vector
源码路径：find_sub_vector.cpp
#include <iostream> // std::cout
#include <algorithm> // std::find_end
#include <vector> // std::vector
bool myfunction(int i, int j)
{
return (i == j);
}
int main()
{
int myints[] = {1, 2, 3, 4, 5, 1, 2, 3, 4, 5};
std::vector<int> haystack(myints, myints + 10);
int needle1[] = {1, 2, 3};
// using default comparison:
std::vector<int>::iterator it;
it = std::find_end(haystack.begin(), haystack.end(), needle1, needle1 + 3);
if (it != haystack.end())
std::cout << "needle1 last found at position " << (it - haystack.begin()) << '\n';
int needle2[] = {4, 5, 1};
// using predicate comparison:
it = std::find_end(haystack.begin(), haystack.end(), needle2, needle2 + 3, myfunction);
if (it != haystack.end())
std::cout << "needle2 last found at position " << (it - haystack.begin()) << '\n';
std::vector<int> needle3{3, 4, 5};
it = std::search(haystack.begin(), haystack.end(), needle3.begin(), needle3.end());
if (it != haystack.end())
std::cout << "needle3 first found at position " << (it - haystack.begin()) << '\n';
return 0;
}输出
needle1 last found at position 5
needle2 last found at position 3
needle3 first found at position 2[CPP] 实现 strcpy
char *strcpy(char *dst, const char *src) {
assert(dst && src);
char *ret = dst;
int len = strlen(src);
if (dst >= src && dst <= src + len) {
dst += len;
src += len;
while (len -- >= 0) {
*dst -- = *src --;
}
} else {
while (len -- >= 0) {
*dst ++ = *src ++;
}
}
return ret;
}[CPP] 排序算法/快速排序
源码路径：quick_sort.cpp
#include <iostream>
int partition(int unsorted[], int low, int high)
{
int pivot = unsorted[low];
while (low < high)
{
while (low < high && unsorted[high] > pivot) high--;
unsorted[low] = unsorted[high];
while (low < high && unsorted[low] <= pivot) low++;
unsorted[high] = unsorted[low];
}
unsorted[low] = pivot;
return low;
}
void quick_sort(int unsorted[], int low, int high)
{
int loc = 0;
if (low < high)
{
loc = partition(unsorted, low, high);
quick_sort(unsorted, low, loc - 1);
quick_sort(unsorted, loc + 1, high);
}
}
int main()
{
int x[] = { 6, 21, 4, 13, 51, 9, 21 };
int len = sizeof(x) / sizeof(int);
quick_sort(x, 0, len - 1);
for each (int i in x)
{
std::cout << i << " ";
}
return 0;
}输出
4 6 9 13 21 21 51[CPP] LRU Cache
源码路径：lru_cache.cpp
#include <iostream>
#include <unordered_map>
#include <vector>
using namespace std;
template <class K, class T>
struct LRUCacheEntry {
K key;
T data;
LRUCacheEntry *prev;
LRUCacheEntry *next;
};
template <class K, class T>
class LRUCache {
private:
unordered_map<K, LRUCacheEntry<K, T> *> mapping;
vector<LRUCacheEntry<K, T> *> freeEntries;
LRUCacheEntry<K, T> *head;
LRUCacheEntry<K, T> *tail;
LRUCacheEntry<K, T> *entries;
public:
LRUCache(size_t size) {
entries = new LRUCacheEntry<K, T>[size];
for (int i = 0; i < size; i++) {
freeEntries.push_back(entries + i);
}
head = new LRUCacheEntry<K, T>;
tail = new LRUCacheEntry<K, T>;
head->prev = NULL;
head->next = tail;
tail->next = NULL;
tail->prev = head;
}
~LRUCache() {
delete head;
delete tail;
delete[] entries;
}
void Debug() {
cout << "All cached elements:" << endl;
LRUCacheEntry<K, T> *ptr = head;
while ((ptr = ptr->next) != tail) {
cout << ptr->key << " ==> " << ptr->data << endl;
}
}
void Put(K key, T data) {
LRUCacheEntry<K, T> *node = mapping[key];
if (node) {
// refresh the link list
detach(node);
node->data = data;
attach(node);
} else {
// cache is full
if (freeEntries.empty()) {
node = tail->prev;
detach(node);
mapping.erase(node->key);
node->data = data;
node->key = key;
attach(node);
} else {
node = freeEntries.back();
freeEntries.pop_back();
node->key = key;
node->data = data;
mapping[key] = node;
attach(node);
}
}
}
T Get(K key) {
LRUCacheEntry<K, T> *node = mapping[key];
if (node) {
detach(node);
attach(node);
return node->data;
} else {
return T();
}
}
private:
void detach(LRUCacheEntry<K, T> *node) {
node->prev->next = node->next;
node->next->prev = node->prev;
}
void attach(LRUCacheEntry<K, T> *node) {
node->next = head->next;
node->prev = head;
head->next = node;
node->next->prev = node;
}
};
int main() {
LRUCache<int, string> lruCache(3);
lruCache.Put(1, "one");
lruCache.Debug();
lruCache.Put(2, "two");
lruCache.Debug();
lruCache.Put(3, "three");
lruCache.Debug();
lruCache.Put(2, "two");
lruCache.Debug();
lruCache.Put(4, "four");
lruCache.Put(1, "one");
lruCache.Debug();
return 0;
}输出
All cached elements:
1 ==> one
All cached elements:
2 ==> two
1 ==> one
All cached elements:
3 ==> three
2 ==> two
1 ==> one
All cached elements:
2 ==> two
3 ==> three
1 ==> one
All cached elements:
1 ==> one
4 ==> four
2 ==> two[CPP] SHA256
#include <iostream>
#include <iomanip>
#include <sstream>
#include <string>
using namespace std;
#include <openssl/sha.h>
string sha256(const string str)
{
unsigned char hash[SHA256_DIGEST_LENGTH];
SHA256_CTX sha256;
SHA256_Init(&sha256);
SHA256_Update(&sha256, str.c_str(), str.size());
SHA256_Final(hash, &sha256);
stringstream ss;
for(int i = 0; i < SHA256_DIGEST_LENGTH; i++)
{
ss << hex << setw(2) << setfill('0') << (int)hash[i];
}
return ss.str();
}
int main(int argc, char **argv) {
cout << sha256(argc == 1 ? "hello world" : argv[1]) << endl;
return 0;
}输出
root@ubuntu:~# g++ a.cpp -lcrypto
root@ubuntu:~# ./a.out
b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9
root@ubuntu:~# ./a.out abc
ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad[CPP] 获取系统信息
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/utsname.h>
#include <sys/statvfs.h>
#include <sys/sysinfo.h>
#include <iostream>
#include <sstream>
#include <thread>
using namespace std;
int main(void) {
struct sysinfo info;
sysinfo(&info);
struct statvfs fsinfo;
statvfs("/", &fsinfo);
struct utsname utsName;
uname(&utsName);
string cpu = std::to_string(std::thread::hardware_concurrency());
string memory = std::to_string(info.totalram * info.mem_unit / 1024 / 1024); // Unit: MB
string totalHDD = std::to_string(fsinfo.f_frsize * fsinfo.f_blocks / 1024 / 1024); // Unit: MB
string freeHDD = std::to_string(fsinfo.f_bsize * fsinfo.f_bfree / 1024 / 1024); // Unit: MB
string systemName = string(utsName.sysname);
string systemRelease = string(utsName.release);
string json;
json += "{";
json += "\"coreCount\":" + cpu + ",";
// TODO:
json += "\"fingerprint\": \"xxx\",";
json += "\"memoryCapability\":" + memory + ",";
json += "\"totalHDD\":" + totalHDD + ",";
json += "\"freeHDD\":" + freeHDD + ",";
json += "\"osType\":\"" + systemName + "\",";
json += "\"osVersion\":\"" + systemRelease + "\"";
json += "}";
cout << json << endl;
string reportIp = "10.0.0.4:48022/ip/report";
auto pos = reportIp.find("/");
string host = reportIp.substr(0, pos);
string uri = reportIp.substr(pos);
cout << "host: " << host << endl;
cout << "uri: " << uri << endl;
return 0;
}输出
[root@wwhs ~]# ./a.out
{"coreCount":1,"fingerprint": "xxx","memoryCapability":991,"totalHDD":20029,"freeHDD":15650,"osType":"Linux","osVersion":"3.10.0-957.12.1.el7.x86_64"}
host: 10.0.0.4:48022
uri: /ip/report[CPP] 自定义类型排序
自定义类型比较函数遵循”严格弱序“即可，可通过如下两种方式实现。
#include <string>
#include <set>
#include <iostream>
using namespace std;
// template<class Key, class Compare = std::less<Key>, class Allocator = std::allocator<Key> > class set;
struct Object {
string id;
int age;
};
struct ObjectComparator {
bool operator()(const Object &a, const Object &b) {
return a.age < b.age;
}
};
struct Object2 {
string id;
int age;
bool operator<(const Object2 &b) const {
return age < b.age;
}
};
int main() {
Object o1 = {"hello", 22};
Object o2 = {"world", 33};
Object o3 = {"x", 22};
set<Object, ObjectComparator> obj;
obj.insert(o1);
obj.insert(o2);
obj.insert(o3); // insert failed
for (auto o : obj) {
cout << o.id << ", " << o.age << endl;
}
Object2 o4 = {"hello", 22};
Object2 o5 = {"world", 33};
Object2 o6 = {"x", 22}; // insert failed
set<Object2> obj2;
obj2.insert(o4);
obj2.insert(o5);
obj2.insert(o6);
for (auto o : obj2) {
cout << o.id << ", " << o.age << endl;
}
return 0;
}输出
root@ubuntu:~/WaykiChain# ./a.out
hello, 22
world, 33
hello, 22
world, 33[CPP] 自定义类型比较
#include <iostream>
#include <map>
#include <cstdint>
#include <string>
using namespace std;
class CoinType {
public:
uint32_t coinType;
uint32_t priceType;
public:
CoinType(uint32_t coinTypeIn, uint32_t priceTypeIn)
: coinType(coinTypeIn), priceType(priceTypeIn) {}
~CoinType() {}
public:
bool operator<(const CoinType &rhs) const {
if (this->priceType == rhs.priceType)
return this->coinType < rhs.coinType;
else {
return this->priceType < rhs.priceType;
}
}
bool operator==(const CoinType &rhs) const {
return (this->coinType == rhs.coinType && this->priceType == rhs.priceType);
}
};
int main() {
map<CoinType, uint64_t> m1;
m1.emplace(CoinType(1, 1), 22);
m1.emplace(CoinType(2, 2), 22);
m1.emplace(CoinType(1, 3), 22);
map<CoinType, uint64_t> m2 = m1;
for (const auto &item : m1)
cout << item.first.coinType << ", " << item.first.priceType << ", " << item.second << endl;
cout << "m1 == m2 ? " << (m1 == m2) << endl;
m1[CoinType(2, 2)] = 11;
for (const auto &item : m1)
cout << item.first.coinType << ", " << item.first.priceType << ", " << item.second << endl;
cout << "m1 == m2 ? " << (m1 == m2) << endl;
return 0;
}输出
1, 1, 22
2, 2, 22
1, 3, 22
m1 == m2 ? 1
1, 1, 22
2, 2, 11
1, 3, 22
m1 == m2 ? 0[CPP] std::tuple/std::tie
#include <iostream>
#include <string>
#include <tuple>
int main() {
int32_t i;
double d;
string s;
std::tuple<int32_t, double, string> t = {1, 2.0, "3"};
std::tie(i, d, s) = t;
std::tie(i, ignore, s) = t;
std::pair<int32_t, string> p = std::make_pair(i, s);
std::tuple<int32_t, string> t2 = std::tie(i, s);
std::tuple<int32_t, double, string> t3 = std::tie(i, d, s);
return 0;
}[CPP] 异步任务
#include <chrono>
#include <future>
#include <iostream>
#include <ctime>
int main() {
std::future<int> future = std::async(std::launch::async, []() {
std::this_thread::sleep_for(std::chrono::seconds(3));
std::srand(std::time(nullptr)); // use current time as seed for random generator
return std::rand();
});
std::cout << "waiting...";
std::future_status status;
do {
status = future.wait_for(std::chrono::milliseconds(20));
if (status == std::future_status::deferred) {
std::cout << "deferred\n";
} else if (status == std::future_status::timeout) {
std::cout << "." << std::flush;
} else if (status == std::future_status::ready) {
std::cout << "ready!\n";
}
} while (status != std::future_status::ready);
std::cout << "result from future is " << future.get() << '\n';
return 0;
}输出
➜ exercise ./a.out
waiting......................................................................................................................................ready!
result from future is 1377911112[CPP] 设计模式/代理模式
源码路径：proxy.cpp
#include <string>
#include <iostream>
class Subject
{
public:
Subject() {}
virtual ~Subject() {}
public:
virtual void Request() = 0;
};
class ConcreteSubject : public Subject
{
public:
ConcreteSubject() {}
~ConcreteSubject() {}
public:
void Request()
{
std::cout << "Done in ConcreteSubject" << std::endl;
}
};
class Proxy : public Subject
{
public:
Proxy(Subject *subject)
:m_subject(subject)
{}
~Proxy() {}
public:
void Request()
{
std::cout << "Call ConcreteSubject::Request() to do the job" << std::endl;
m_subject->Request();
}
private:
Subject * m_subject;
};
int main()
{
Subject *subject = new ConcreteSubject();
Proxy *proxy = new Proxy(subject);
proxy->Request();
delete proxy;
proxy = nullptr;
delete subject;
subject = nullptr;
return 0;
}输出
[root@localhost design_pattern]# g++ proxy.cpp -std=c++11
[root@localhost design_pattern]# ./a.out
Call ConcreteSubject::Request() to do the job
Done in ConcreteSubject[CPP] 策略模式
源码路径：strategy.cpp
#include <string>
#include <iostream>
class Strategy
{
public:
Strategy() {}
virtual ~Strategy() {}
public:
virtual void AlgrithmInterface() = 0;
};
class ConcreteStrategyA : public Strategy
{
public:
ConcreteStrategyA() {}
~ConcreteStrategyA() {}
public:
void AlgrithmInterface()
{
std::cout << "ConcreteStategyA::AlgrithmInterface()" << std::endl;
}
};
class ConcreteStrategyB : public Strategy
{
public:
ConcreteStrategyB() {}
~ConcreteStrategyB() {}
public:
void AlgrithmInterface()
{
std::cout << "ConcreteStrategyB::AlgrithmInterface()" << std::endl;
}
};
class Context
{
public:
Context(Strategy *strategy)
{
m_strategy = strategy;
}
~Context() {}
public:
void DoAction()
{
if (m_strategy)
{
m_strategy->AlgrithmInterface();
}
}
private:
Strategy * m_strategy;
};
int main()
{
Strategy *strategy = new ConcreteStrategyA();
Context *context = new Context(strategy);
context->DoAction();
delete strategy;
strategy = nullptr;
delete context;
context = nullptr;
return 0;
}输出
ConcreteStategyA::AlgrithmInterface()[CPP] 设计模式/单例模式
饿汉式
源码路径：hungry_singleton.cpp
#include <iostream>
class Singleton {
public:
static Singleton* Instance()
{
return &m_instance;
}
private:
Singleton() {}
Singleton(const Singleton&) {}
Singleton& operator=(const Singleton&) {}
static Singleton m_instance;
};
Singleton Singleton::m_instance;
int main()
{
Singleton *singleton1 = Singleton::Instance();
Singleton *singleton2 = Singleton::Instance();
if (singleton1 == singleton2)
{
std::cout << "Got the same instance" << std::endl;
}
else
{
std::cout << "unexpected error" << std::endl;
}
return 0;
}输出
[root@localhost design_pattern]# g++ hungry_singleton.cpp -std=c++11
[root@localhost design_pattern]# ./a.out
Got the same instance饱汉式
源码路径：full_singleton.cpp
#include <iostream>
class Singleton {
public:
static Singleton* Instance()
{
if (m_instance == nullptr)
{
m_instance = new Singleton();
}
return m_instance;
}
static void Release()
{
if (m_instance != nullptr)
{
delete m_instance;
m_instance = nullptr;
}
}
private:
Singleton() {}
Singleton(const Singleton&) {}
Singleton& operator=(const Singleton&) {}
static Singleton *m_instance;
};
Singleton *Singleton::m_instance = nullptr;
int main()
{
Singleton *singleton1 = Singleton::Instance();
Singleton *singleton2 = Singleton::Instance();
if (singleton1 == singleton2)
{
std::cout << "Got the same instance" << std::endl;
}
else
{
std::cout << "unexpected error" << std::endl;
}
singleton1->Release();
return 0;
}输出
[root@localhost design_pattern]# g++ full_singleton.cpp -std=c++11
[root@localhost design_pattern]# ./a.out
Got the same instance双重检测（线程安全）
#include <iostream>
#include <mutex>
class Singleton {
public:
static Singleton* Instance()
{
if (m_instance == nullptr)
{
m_mtx.lock();
if (m_instance == nullptr)
{
m_instance = new Singleton();
}
m_mtx.unlock();
}
return m_instance;
}
static void Release()
{
if (m_instance != nullptr)
{
m_mtx.lock();
if (m_instance != nullptr)
{
delete m_instance;
m_instance = nullptr;
}
m_mtx.unlock();
}
}
private:
Singleton() {}
Singleton(const Singleton&) {}
Singleton& operator=(const Singleton&) {}
static Singleton *m_instance;
static std::mutex m_mtx;
};
Singleton *Singleton::m_instance = nullptr;
std::mutex Singleton::m_mtx;
int main()
{
Singleton *singleton1 = Singleton::Instance();
Singleton *singleton2 = Singleton::Instance();
if (singleton1 == singleton2)
{
std::cout << "Got the same instance" << std::endl;
}
else
{
std::cout << "unexpected error" << std::endl;
}
singleton1->Release();
return 0;
}输出
[root@localhost design_pattern]# g++ double_check_singleton.cpp -std=c++11
[root@localhost design_pattern]# ./a.out
Got the same instance模板
#include <iostream>
#include <mutex>
template<typename T>
class Singleton {
public:
static T* Instance()
{
if (m_instance == nullptr)
{
m_instance = new T();
}
return m_instance;
}
static void Release()
{
if (m_instance != nullptr)
{
delete m_instance;
m_instance = nullptr;
}
}
private:
Singleton() {}
Singleton(const Singleton&) {}
Singleton& operator=(const Singleton&) {}
static T *m_instance;
};
template<typename T>
T *Singleton<T>::m_instance = nullptr;
class A
{
public:
void SayHello()
{
std::cout << "hello world" << std::endl;
}
};
int main()
{
A *a1 = Singleton<A>::Instance();
A *a2 = Singleton<A>::Instance();
if (a1 == a2)
{
std::cout << "Got the same instance" << std::endl;
}
else
{
std::cout << "unexpected error" << std::endl;
}
a1->SayHello();
return 0;
}输出
[root@localhost design_pattern]# g++ template_singleton.cpp -std=c++11
[root@localhost design_pattern]# ./a.out
Got the same instance
hello world[CPP] 设计模式/适配器模式
类适配器
源码路径：class_adapter.cpp
#include <iostream>
class Target
{
public:
Target() {}
virtual ~Target() {}
public:
virtual void Request() = 0;
};
class Adaptee
{
public:
Adaptee(){}
virtual ~Adaptee() {}
public:
virtual void SpecificRequest() = 0;
};
class Adapter : public Target, public Adaptee
{
public:
Adapter() {}
~Adapter() {}
public:
void Request()
{
std::cout << "Transfer Specific Request to Reuest" << std::endl;
SpecificRequest();
std::cout << "Finally, Request" << std::endl;
}
void SpecificRequest()
{
std::cout << "Specific Request" << std::endl;
}
};
int main()
{
Target *target = new Adapter();
target->Request();
delete target;
target = nullptr;
return 0;
}输出
[root@localhost design_pattern]# g++ class_adapter.cpp -std=c++11
[root@localhost design_pattern]# ./a.out
Transfer Specific Request to Reuest
Specific Request
Finally, Request对象适配器
源码路径：object_adapter.cpp
#include <iostream>
class Target
{
public:
Target() {}
virtual ~Target() {}
public:
virtual void Request() = 0;
};
class Adaptee
{
public:
Adaptee(){}
virtual ~Adaptee() {}
public:
void SpecificRequest()
{
std::cout << "Specific Request" << std::endl;
}
};
class Adapter : public Target
{
public:
Adapter(Adaptee *adaptee) {}
~Adapter() {}
public:
void Request()
{
std::cout << "Transfer Specific Request to Reuest" << std::endl;
m_adaptee->SpecificRequest();
std::cout << "Finally, Request" << std::endl;
}
private:
Adaptee * m_adaptee;
};
int main()
{
Adaptee *adaptee = new Adaptee();
Target *target = new Adapter(adaptee);
target->Request();
delete target;
target = nullptr;
return 0;
}输出
[root@localhost design_pattern]# g++ object_adapter.cpp -std=c++11
[root@localhost design_pattern]# ./a.out
Transfer Specific Request to Reuest
Specific Request
Finally, Request[CPP] 设计模式/桥接模式
源码路径：bridge.cpp
#include <iostream>
#include <string>
class USB
{
public:
USB() {}
virtual ~USB() {}
public:
virtual void Transfer() = 0;
};
// USB 2.0
class USB20 : public USB
{
public:
USB20() {}
~USB20() {}
public:
void Transfer()
{
std::cout << "Transfer by USB 2.0" << std::endl;
}
};
// USB 3.0
class USB30 : public USB
{
public:
USB30() {}
~USB30() {}
public:
void Transfer()
{
std::cout << "Transfer by USB 3.0, faster" << std::endl;
}
};
class PC
{
public:
PC() {}
virtual ~PC() {}
public:
virtual void Transfer(USB *usb) = 0;
};
class DellPC : public PC
{
public:
DellPC() {}
~DellPC() {}
public:
void Transfer(USB *usb)
{
std::cout << "Dell PC, try to transfer data by USB device" << std::endl;
usb->Transfer();
}
};
int main()
{
USB *usb20 = new USB20();
USB *usb30 = new USB30();
PC *pc = new DellPC();
pc->Transfer(usb20);
pc->Transfer(usb30);
delete usb20;
usb20 = nullptr;
delete usb30;
usb30 = nullptr;
delete pc;
pc = nullptr;
return 0;
}输出
[root@localhost design_pattern]# g++ bridge.cpp -std=c++11
[root@localhost design_pattern]# ./a.out
Dell PC, try to transfer data by USB device
Transfer by USB 2.0
Dell PC, try to transfer data by USB device
Transfer by USB 3.0, faster[CPP] 设计模式/观察者模式
源码路径：observer.cpp
#include <iostream>
#include <list>
#include <string>
class Observer
{
public:
Observer() {}
virtual ~Observer() {}
public:
virtual void Update(int status) = 0;
};
class ConcreteObserver : public Observer
{
public:
ConcreteObserver() {}
~ConcreteObserver() {}
public:
void Update(int status)
{
std::cout << "The target subject is changing status: " << status << std::endl;
}
};
class Subject
{
public:
Subject() {}
virtual ~Subject() {}
public:
virtual void Attach(Observer *observer) = 0;
virtual void Detach(Observer *observer) = 0;
virtual void Notify() = 0;
virtual void SetStatus(int status) = 0;
virtual int GetStatus() = 0;
private:
int status;
};
class ConcreteSubject : public Subject
{
public:
ConcreteSubject() {}
virtual ~ConcreteSubject() {}
void Attach(Observer *observer)
{
m_observers.push_back(observer);
}
void Detach(Observer* observer)
{
m_observers.remove(observer);
}
void Notify()
{
for (auto itor = m_observers.begin(); itor != m_observers.end(); itor++)
{
(*itor)->Update(m_status);
}
}
void SetStatus(int status)
{
m_status = status;
}
int GetStatus()
{
return m_status;
}
private:
std::list<Observer*> m_observers;
int m_status;
};
int main()
{
Observer *observer = new ConcreteObserver();
Subject *subject = new ConcreteSubject();
subject->Attach(observer);
subject->SetStatus(99);
std::cout << "Subject's status: " << subject->GetStatus() << std::endl;
subject->Notify();
subject->Detach(observer);
delete observer;
observer = nullptr;
delete subject;
subject = nullptr;
return 0;
}输出
[root@localhost design_pattern]# g++ observer.cpp -std=c++11
[root@localhost design_pattern]# ./a.out
Subject's status: 99
The target subject is changing status: 99[CPP] 设计模式/装饰器模式
源码路径：decorator.cpp
#include <iostream>
#include <string>
class Phone
{
public:
Phone() {}
virtual ~Phone() {}
virtual void ShowDecorate() = 0;
};
class iPhone : public Phone
{
public:
iPhone(std::string name)
: m_name(name) {}
~iPhone() {}
void ShowDecorate()
{
std::cout << "Name: " << m_name << std::endl;
}
private:
std::string m_name;
};
class NokiaPhone : public Phone
{
public:
NokiaPhone(std::string name)
: m_name(name)
{
}
~NokiaPhone()
{
}
void ShowDecorate()
{
std::cout << "Name: " << m_name << std::endl;
}
private:
std::string m_name;
};
class DecoratorPhone : public Phone
{
public:
DecoratorPhone(Phone *phone)
: m_phone(phone)
{
}
virtual void ShowDecorate()
{
m_phone->ShowDecorate();
}
private:
Phone *m_phone;
};
class DecoratePhoneA : public DecoratorPhone
{
public:
DecoratePhoneA(Phone *ph)
: DecoratorPhone(ph)
{
}
void ShowDecorate()
{
DecoratorPhone::ShowDecorate();
AddDecorate();
}
private:
void AddDecorate()
{
std::cout << "Decorator: HiFi Audio System" << std::endl;
}
};
class DecoratePhoneB : public DecoratorPhone
{
public:
DecoratePhoneB(Phone *ph)
: DecoratorPhone(ph)
{
}
void ShowDecorate()
{
DecoratorPhone::ShowDecorate();
AddDecorate();
}
private:
void AddDecorate()
{
std::cout << "Decorator: Duel Camera" << std::endl;
}
};
int main()
{
Phone *nokia = new NokiaPhone("Nokia N8");
Phone *iphone = new iPhone("iPhone 4");
Phone *dpa = new DecoratePhoneA(nokia);
Phone *dpb = new DecoratePhoneB(iphone);
nokia->ShowDecorate();
dpa->ShowDecorate();
dpb->ShowDecorate();
delete nokia;
nokia = nullptr;
delete iphone;
iphone = nullptr;
delete dpa;
dpa = nullptr;
delete dpb;
dpb = nullptr;
return 0;
}输出
[root@localhost design_pattern]# g++ decorator.cpp -std=c++11
[root@localhost design_pattern]# ./a.out
Name: Nokia N8
Name: Nokia N8
Decorator: HiFi Audio System
Name: iPhone 4
Decorator: Duel Camera[CPP] 设计模式/职责链模式
#include <iostream>
class Handler
{
public:
Handler() {}
virtual ~Handler() {}
public:
virtual void HandleRequest(int count) = 0;
void SetSuccessor(Handler *successor)
{
m_successor = successor;
}
Handler *GetSuccessor()
{
return m_successor;
}
protected:
Handler *m_successor;
};
class ConcreteHandlerA : public Handler
{
public:
ConcreteHandlerA() {}
~ConcreteHandlerA() {}
public:
void HandleRequest(int count)
{
if (count < 100)
{
std::cout << "A: I can do it, done" << std::endl;
}
else
{
std::cout << "A: I can not do it, next" << std::endl;
if (GetSuccessor() != nullptr)
{
GetSuccessor()->HandleRequest(count);
}
}
}
};
class ConcreteHandlerB : public Handler
{
public:
ConcreteHandlerB() {}
~ConcreteHandlerB() {}
public:
void HandleRequest(int count)
{
if (count >= 100)
{
std::cout << "B: I can do it, done" << std::endl;
}
}
};
int main()
{
Handler *a = new ConcreteHandlerA();
Handler *b = new ConcreteHandlerB();
a->SetSuccessor(b);
a->HandleRequest(50);
a->HandleRequest(150);
a->SetSuccessor(nullptr);
delete b;
b = nullptr;
delete a;
a = nullptr;
return 0;
}输出
[root@localhost design_pattern]# g++ chain_of_responsibility.cpp -std=c++11
[root@localhost design_pattern]# ./a.out
A: I can do it, done
A: I can not do it, next
B: I can do it, done[CPP] 设计模式/模板方法模式
#include <iostream>
#include <string>
class AbstractClass
{
public:
AbstractClass() {}
virtual ~AbstractClass() {}
public:
void TemplateMethod()
{
this->Primitive1();
this->Primitive2();
}
protected:
virtual void Primitive1() = 0;
virtual void Primitive2() = 0;
};
class ConcreteClass1 : public AbstractClass
{
public:
ConcreteClass1() {}
~ConcreteClass1() {}
protected:
void Primitive1()
{
std::cout << "ConcreteClass1::Primitive1()" << std::endl;
}
void Primitive2()
{
std::cout << "ConcreteClass1::Primitive2()" << std::endl;
}
};
class ConcreteClass2 : public AbstractClass
{
public:
ConcreteClass2() {}
~ConcreteClass2() {}
protected:
void Primitive1()
{
std::cout << "ConcreteClass2::Primitive1()" << std::endl;
}
void Primitive2()
{
std::cout << "ConcreteClass2::Primitive2()" << std::endl;
}
};
int main(int argc, char* argv[]) {
AbstractClass* p1 = new ConcreteClass1();
AbstractClass* p2 = new ConcreteClass2();
p1->TemplateMethod();
p2->TemplateMethod();
delete p1;
p1 = nullptr;
delete p2;
p2 = nullptr;
return 0;
}输出
[root@localhost design_pattern]# g++ template_function.cpp -std=c++11
[root@localhost design_pattern]# ./a.out
ConcreteClass1::Primitive1()
ConcreteClass1::Primitive2()
ConcreteClass2::Primitive1()
ConcreteClass2::Primitive2()[CPP] LevelDB 基础使用
#include <iostream>
#include <cassert>
#include "leveldb/db.h"
#include "leveldb/write_batch.h"
int main()
{
// Open a database.
leveldb::DB* db;
leveldb::Options opts;
opts.create_if_missing = true;
leveldb::Status status = leveldb::DB::Open(opts, "./testdb", &db);
assert(status.ok());
// Write data.
status = db->Put(leveldb::WriteOptions(), "key", "value");
assert(status.ok());
// Read data.
std::string val;
status = db->Get(leveldb::ReadOptions(), "key", &val);
assert(status.ok());
std::cout << val << std::endl;
// Batch atomic write.
leveldb::WriteBatch batch;
batch.Delete("key");
batch.Put("key0", "value0");
batch.Put("key1", "value1");
batch.Put("key2", "value2");
status = db->Write(leveldb::WriteOptions(), &batch);
assert(status.ok());
// Scan database.
leveldb::Iterator* it = db->NewIterator(leveldb::ReadOptions());
for (it->SeekToFirst(); it->Valid(); it->Next()) {
std::cout << it->key().ToString() << ": " <<
it->value().ToString() << std::endl;
}
assert(it->status().ok());
// Range scan, example: [key1, value2)
for (it->Seek("key1");
it->Valid() && it->key().ToString() < "value2";
it->Next()) {
std::cout << it->key().ToString() << ": " <<
it->value().ToString() << std::endl;
}
// Close a database.
delete db;
}[Python] 输出不换行
**环境：**Python 2.7.14
# -*- coding:utf-8 -*-
if __name__ == '__main__':
print("hello")
print("world")
print("hello"),
print("world")输出
hello
world
hello world[Python] 获取 unixstamp
import time
import datetime
import calendar
original_seconds = time.time()
print original_seconds
seconds = int(time.time())
print seconds
millis = int(round(time.time() * 1000))
print millis
now = datetime.datetime.utcnow()
tt = long(calendar.timegm(now.utctimetuple()))
print tt输出
1527122035.76
1527122035
1527122035756
1527122035[Python] 日期时间格式化
# -*- coding:utf-8 -*-
import datetime
import time
if __name__ == '__main__':
date = datetime.datetime.now().strftime("%Y-%m-%d")
print(date)
now = datetime.datetime.strptime("2018-04-25 18:00:34.123456", "%Y-%m-%d %H:%M:%S.%f")
print(now)
now = datetime.datetime.utcnow()
vn_now = now + datetime.timedelta(hours=7)
vn_date = vn_now.strftime("%Y-%m-%d")
print(vn_date)输出
2018-05-24
2018-04-25 18:00:34.123456
2018-05-24[Python] 计算比特币发行总量
# -*- coding: utf-8 -*-
# 初始的块奖励为 50 BTC
start_block_reward = 50
# 以10分钟为一个区块的间隔，210000 个块共约 4 年时间
reward_interval = 210000
def max_money():
# 50 BTC = 50 0000 0000 Satoshis
current_reward = 50 * 10**8
total = 0
while current_reward > 0:
total += reward_interval * current_reward
current_reward /= 2
return total
print "Total BTC to ever be created:", max_money(), "Satoshis"输出
Total BTC to ever be created: 2099999997690000 Satoshis[Python] 简化的工作量证明算法
可以任意调整难度值（按二进制 bit 数来设定，即哈希值开头多少个 bit 必须是 0）
# -*- coding: utf-8 -*-
# example of proof-of-work algorithm
import hashlib
import time
max_nonce = 2 ** 32 # 4 billion
def proof_of_work(header, difficulty_bits):
# calculate the difficulty target
target = 2 ** (256-difficulty_bits)
for nonce in xrange(max_nonce):
hash_result = hashlib.sha256(str(header)+str(nonce)).hexdigest()
# check if this is a valid result, below the target
if long(hash_result, 16) < target:
print "Success with nonce %d" % nonce
print "Hash is %s" % hash_result
return (hash_result,nonce)
print "Failed after %d (max_nonce) tries" % nonce
return nonce
if __name__ == '__main__':
nonce = 0
hash_result = ''
# difficulty from 0 to 31 bits
for difficulty_bits in xrange(32):
difficulty = 2 ** difficulty_bits
print "Difficulty: %ld (%d bits)" % (difficulty, difficulty_bits)
print "Starting search..."
# checkpoint the current time
start_time = time.time()
# make a new block which includes the hash from the previous block
# we fake a block of transactions - just a string
new_block = 'test block with transactions' + hash_result
# find a valid nonce for the new block
(hash_result, nonce) = proof_of_work(new_block, difficulty_bits)
# checkpoint how long it took to find a result
end_time = time.time()
elapsed_time = end_time - start_time
print "Elapsed Time: %.4f seconds" % elapsed_time
if elapsed_time > 0:
# estimate the hashes per second
hash_power = float(long(nonce)/elapsed_time)
print "Hashing Power: %ld hashes per second" % hash_power输出
输出较多，仅列出一小部分
Difficulty: 1 (0 bits)
Starting search...
Success with nonce 0
Hash is ff8253ed10b5f719d52a709a66af8cd5e2054f702e675af4ca0cae70f0988634
Elapsed Time: 0.0001 seconds
Hashing Power: 0 hashes per second
Difficulty: 2 (1 bits)
Starting search...
Success with nonce 0
Hash is 22c608547e239faf5c353e7ebd204042760b93891d1d0be9ab488d36c73c077b
Elapsed Time: 0.0000 seconds
Hashing Power: 0 hashes per second
Difficulty: 4 (2 bits)
Starting search...
Success with nonce 2
Hash is 0635f41cdb98c6e73516f84fc88da19a13a3bac6298dbfc0df5170bac93ba4dd
Elapsed Time: 0.0000 seconds
Hashing Power: 55553 hashes per second
Difficulty: 8 (3 bits)
Starting search...
Success with nonce 9
Hash is 1c1c105e65b47142f028a8f93ddf3dabb9260491bc64474738133ce5256cb3c1
Elapsed Time: 0.0001 seconds
Hashing Power: 140329 hashes per second
Difficulty: 16 (4 bits)
Starting search...
Success with nonce 25
Hash is 0f7becfd3bcd1a82e06663c97176add89e7cae0268de46f94e7e11bc3863e148
Elapsed Time: 0.0001 seconds
Hashing Power: 227456 hashes per second
Difficulty: 32 (5 bits)
Starting search...
Success with nonce 36
Hash is 029ae6e5004302a120630adcbb808452346ab1cf0b94c5189ba8bac1d47e7903
Elapsed Time: 0.0003 seconds
Hashing Power: 108085 hashes per second
Difficulty: 64 (6 bits)
Starting search...
Success with nonce 0
Hash is 0083214fa878cea749bd07bd77e92b311be876dd72f3d4924d5ae4ead54febe5
Elapsed Time: 0.0001 seconds
Hashing Power: 0 hashes per second
Difficulty: 128 (7 bits)
Starting search...
Success with nonce 26
Hash is 00f7abab177613afc42270e3f5f79ffddd694093030663b32fe26ce2a377a993
Elapsed Time: 0.0008 seconds
Hashing Power: 32956 hashes per second
Difficulty: 256 (8 bits)[Python] 字串串十六进制转换
**环境：**Python 2.7.14
源码：点此下载
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import sys
choose = ""
data = ""
def hex2char():
output = data.decode('hex')
print output
def char2hex():
output = data.encode('hex')
print output
if __name__ == '__main__':
if len(sys.argv) == 3:
choose = sys.argv[1]
data = sys.argv[2]
if choose.lower() == 'hex2char':
hex2char()
if choose.lower() == 'char2hex':
char2hex()
if choose.lower() != 'hex2char' and choose.lower() != 'char2hex':
print "Wrong param,try again"
else:
print "Usage: <hex2char|char2hex> <data>"输出
$ ./hex_str.py char2hex "hello wolrd"
68656c6c6f20776f6c7264
$ ./hex_str.py hex2char "68656c6c6f20776f6c7264"
hello wolrd[Python] 列表
列表的遍历
#!/usr/bin/env python
# -*- coding: utf-8 -*-
if __name__ == '__main__':
my_list = ['html', 'js', 'css', 'python']
for i in my_list:
print("index:%d, value:%s" % (my_list.index(i), i))
for i in range(len(my_list)):
print("index:%d, value:%s" % (i, my_list[i]))
for i, val in enumerate(my_list):
print("index:%d, value:%s" % (i, val))
# 只是改变索引的输出，默认从 0 开始，如下设置从 2 开始
for i, val in enumerate(my_list, 2):
print("index:%d, value:%s" % (i, val))输出
index:0, value:html
index:1, value:js
index:2, value:css
index:3, value:python
index:0, value:html
index:1, value:js
index:2, value:css
index:3, value:python
index:0, value:html
index:1, value:js
index:2, value:css
index:3, value:python
index:2, value:html
index:3, value:js
index:4, value:css
index:5, value:python列表的去重
#!/usr/bin/env python
# -*- coding: utf-8 -*-
if __name__ == '__main__':
my_list = ['html', 'js', 'css', 'python', 'cpp', 'css']
print my_list
my_set = set(my_list)
my_list = [x for x in my_set]
print my_list输出
['html', 'js', 'css', 'python', 'cpp', 'css']
['python', 'cpp', 'html', 'css', 'js'][Python] 集合
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import traceback
if __name__ == '__main__':
set1 = set([1, 3, 5, 6, 7])
set2 = set([2, 3, 4, 5, 8])
print "set1:", set1
print "set2:", set2
if 4 in set1:
print "4 in set1"
else:
print "4 not in set1"
# 添加元素
set1.add(9)
print "set1:", set1
set1.update([9, 10, 11])
print "set1:", set1
# 删除元素
try:
set1.remove(99)
except Exception as ex:
print traceback.format_exc()
print "after remove 99, set1:", set1
set1.discard(99)
print "after discard 99, set1:", set1
set1.remove(10)
print "after remove 10, set1:", set1
set1.discard(9)
print "after discard 9, set1:", set1
# 测试是否 set1 中每一个元素都在 set2 中
if set1.issubset(set2):
print "set1 is subset of set2"
else:
print "set1 is not subset of set2"
# 测试是否 set2 中每一个元素都在 set1 中
if set1.issuperset(set2):
print "set1 is superset of set2"
else:
print "set1 is not superset of set2"
print "set1:", set1
print "set2:", set2
# x ∈ set1 || x ∈ set2
print set1.union(set2)
# (x ∈ set1 && x ∉ set2) || (x ∈ set2 && x ∉ set1)
print set1.symmetric_difference(set2)
# x ∈ set1 && x ∈ set2
print set1.intersection(set2)
# x ∈ set1 && x ∉ set2
print set1.difference(set2)
print set2.difference(set1)输出
set1: set([1, 3, 5, 6, 7])
set2: set([8, 2, 3, 4, 5])
4 not in set1
set1: set([1, 3, 5, 6, 7, 9])
set1: set([1, 3, 5, 6, 7, 9, 10, 11])
Traceback (most recent call last):
File "d:\Blog\archives\debug\debug.py", line 26, in <module>
set1.remove(99)
KeyError: 99
after remove 99, set1: set([1, 3, 5, 6, 7, 9, 10, 11])
after discard 99, set1: set([1, 3, 5, 6, 7, 9, 10, 11])
after remove 10, set1: set([1, 3, 5, 6, 7, 9, 11])
after discard 9, set1: set([1, 3, 5, 6, 7, 11])
set1 is not subset of set2
set1 is not superset of set2
set1: set([1, 3, 5, 6, 7, 11])
set2: set([8, 2, 3, 4, 5])
set([1, 2, 3, 4, 5, 6, 7, 8, 11])
set([1, 2, 4, 6, 7, 8, 11])
set([3, 5])
set([1, 11, 6, 7])
set([8, 2, 4])[Python] range 与 xrange
# -*- coding: utf-8 -*-
for i in range(2, 10, 3):
print i
for i in range(3):
print i
print range(2, 10, 2)
for j in xrange(2, 10, 3):
print j
for j in xrange(3):
print j
print xrange(2, 10, 2)
print list(xrange(2, 10, 2))输出
2
5
8
0
1
2
[2, 4, 6, 8]
2
5
8
0
1
2
xrange(2, 10,
[2, 4, 6, 8][Python] 字典的遍历
**效率：**由高到低，性能要求高的地方需要注意
from time import clock
l = [(x, x) for x in xrange(1000000)]
d = dict(l)
t0 = clock()
for i in d:
t = i + d[i]
t1 = clock()
for k, v in d.iteritems():
t = k + v
t2 = clock()
for k, v in zip(d.iterkeys(), d.itervalues()):
t = k + v
t3 = clock()
for k, v in d.items():
t = k + v
t4 = clock()
print t1-t0, t2-t1, t3-t2, t4-t3输出
0.147005027863 0.151357206668 0.273842580021 0.696996068627[Python] 构造、析构
class X(object):
def __init__(self, a, b, range):
self.a = a
self.b = b
self.range = range
print('__init__ with {}, {}, {}'.format(self.a, self.b, self.range))
def __call__(self, a, b):
self.a = a
self.b = b
print('__call__ with {}, {}'.format(self.a, self.b))
def __del__(self):
del self.a
del self.b
del self.range
print('__del__')
if __name__ == '__main__':
x = X(1, 2, 3)
x(3, 4)输出
__init__ with 1, 2, 3
__call__ with 3, 4
__del__[Python] 全局变量
全局变量可在函数中直接使用
函数中存在同名变量，局部变量覆盖全局变量作用域
函数中显示声明 global var，实现对全局变量的修改；对于列表、字典等全局变量，不需要额外的 global 声明
#! /usr/bin/python
a = 1
b = [2, 3]
def func1():
a = 11
print "in func1 a:", a
b[0] = 22
print "in func1 b:", b
def func2():
global a
a = 11
print "in func a:", a
b[1] = 33
print "in func b:", b
if __name__ == '__main__':
print "init, a:", a
print "init, b:", b
func1()
print "after func1 a:", a
print "after func1 b:", b
func2()
print "after func2 a:", a
print "after func2 b:", b输出
init, a: 1
init, b: [2, 3]
in func1 a: 11
in func1 b: [22, 3]
after func1 a: 1
after func1 b: [22, 3]
in func a: 11
in func b: [22, 33]
after func2 a: 11
after func2 b: [22, 33][Python] lambda 表达式
# -*- coding: utf-8 -*-
# 常规使用
f = lambda x : x + 1
print f(99)
# 映射
print map(lambda x : x + 1, [1, 2, 3])
print map(lambda x: x*x, [y for y in range(10)])
# 过滤
foo = [2, 18, 9, 22, 17, 24, 8, 12, 27]
print filter(lambda x : x % 3 == 0, foo)
# 归纳
print reduce(lambda x, y : x + y, foo)
# 闭包
def add(n):
return lambda x : x + n
print add(3)(5)
# 等价于
add_3 = add(3)
print add_3(5)输出
100
[2, 3, 4]
[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
[18, 9, 24, 12, 27]
139
8
8[Python] Redis 使用
**环境：**Python 2.7.14
**安装 redis：**pip install redis redis-py-cluster
源码：点此下载
# -*- coding:utf-8 -*-
import datetime
import time
class RedisHelper(object):
def __init__(self, redis_type=None, **args):
if redis_type == "cluster":
import rediscluster
self.r_conn = rediscluster.StrictRedisCluster(**args)
else:
import redis
self.r_conn = redis.StrictRedis(**args)
def GetValue(self, name):
return self.r_conn.get(name)
def IncrValue(self, name):
return self.r_conn.incr(name)
def SetValue(self, name, value):
self.r_conn.set(name, value)
def GetSetValue(self, name, value):
return self.r_conn.getset(name, value)
if __name__ == '__main__':
# 单点
conn_dict = {'host': '127.0.0.1', 'port': 6379}
redis_type = 'single'
# 集群
# conn_dict={"startup_nodes":[
# {'host':'192.168.0.3', 'port':4000},
# {'host':'192.168.0.3', 'port':5000},
# {'host':'192.168.0.4', 'port':6000},
# {'host':'192.168.0.5', 'port':7000}]}
# redis_type='cluster'
myredis = RedisHelper(redis_type, **conn_dict)
print(myredis.SetValue('name', 'kevin'))
print(myredis.GetValue('name'))
print(myredis.GetSetValue('nickname', 0))
print(myredis.GetValue('nickname'))输出
None
kevin
0
0[Python] MySQL 使用
**环境：**Python 2.7.14
源码：点此下载
**Tag：**查询、批量插入、truncate
# coding=utf-8
import sys
import time
import datetime
import logging
import MySQLdb
import MySQLdb.cursors
logger = logging.getLogger("latest_active_user")
logger.setLevel(logging.DEBUG)
# user_tbl
user_tbl = {
"host": "10.10.10.10",
"port": 3306,
"user": "lsb",
"passwd": "lsb",
"db": "db"
}
latest_active_user = {
"host": "10.10.10.10",
"port": 3306,
"user": "lsb",
"passwd": "lsb",
"db": "db"
}
# push_stat_{}
push_stat = {
"host": "10.10.10.10",
"port": 4000,
"user": "lsb",
"passwd": "lsb",
"db": "db"
}
# user_register_{}
user_register = {
"host": "10.10.10.10",
"port": 3306,
"user": "lsb",
"passwd": "lsb",
"db": "db"
}
# user_action_log_{}
user_action_log = {
"host": "10.10.10.10",
"port": 3306,
"user": "lsb",
"passwd": "lsb",
"db": "db"
}
user_id_set = set()
def format_date(diff_days):
date_time = datetime.datetime.utcnow() + datetime.timedelta(hours=7)
return (date_time + datetime.timedelta(days=diff_days)).strftime("%Y%m%d")
def init_logger(log_module):
handler = logging.FileHandler(filename="latest_active_user.log", mode='w')
# handler.setLevel(logging.DEBUG)
formatter = logging.Formatter("%(asctime)s - %(levelname)s - %(message)s")
handler.setFormatter(formatter)
log_module.addHandler(handler)
def get_db_conn(mysql_config):
db = MySQLdb.connect(host=mysql_config['host'],
port=mysql_config['port'],
user=mysql_config['user'],
passwd=mysql_config['passwd'],
db=mysql_config['db'],
cursorclass=MySQLdb.cursors.DictCursor)
db.set_character_set('utf8mb4')
cursor = db.cursor()
cursor.execute('SET NAMES utf8mb4;')
return db, cursor
def truncate_table_helper():
sql = "truncate table `db`.`latest_active_user_tbl`"
logger.debug("database: %s, sql: %s", latest_active_user_tbl, sql)
db, cursor = get_db_conn(latest_active_user)
cursor.execute(sql)
db.commit()
cursor.close()
db.close()
def fetch_helper(conn, sql):
logger.debug("database: %s, sql: %s", conn, sql)
db, cursor = get_db_conn(conn)
cursor.execute(sql)
ret = cursor.fetchall()
cursor.close()
db.close()
if not ret:
logger.warn("sql not ret")
return ret
def batch_insert_helper(user_id_set):
if len(user_id_set) == 0:
return
total = 0
try:
db, cursor = get_db_conn(latest_active_user)
batch = 100000
values = []
for i in user_id_set:
values.append((i,))
# 批量插入
if len(values) == batch:
total += batch
logger.info("batch insert, count: %d", len(values))
cursor.executemany(
'INSERT INTO `db`.`latest_active_user_tbl` (user_id) VALUES (%s)', values)
db.commit()
values = []
if len(values) > 0:
total += len(values)
logger.info("final batch insert, count: %d", len(values))
cursor.executemany(
'INSERT INTO `db`.`latest_active_user_tbl` (user_id) VALUES (%s)', values)
db.commit()
values = []
cursor.close()
db.close()
except MySQLdb.Error as ex:
logger.error("MySQL Error %d: %s", ex.args[0], ex.args[1])
return total
def from_push_stat():
sql = """
select distinct(user_id) from `db`.`push_stat_{}`
union select distinct(user_id) from `db`.`push_stat_{}`
union select distinct(user_id) from `db`.`push_stat_{}`
union select distinct(user_id) from `db`.`push_stat_{}`
union select distinct(user_id) from `db`.`push_stat_{}`
union select distinct(user_id) from `db`.`push_stat_{}`
union select distinct(user_id) from `db`.`push_stat_{}`
""".format(format_date(-1), format_date(-2), format_date(-3), format_date(-4),
format_date(-5), format_date(-6), format_date(-7))
users = fetch_helper(push_stat, sql)
if not users:
logger.info("call fetch_helper(), no record")
else:
logger.info("call fetch_helper(), got %d record(s)", len(users))
for row in users:
user_id_set.add(row['user_id'])
def from_user():
sql = """
select id from `db`.`user_tbl`
where create_time > date_add(now(), interval - 7 day)
"""
users = fetch_helper(user, sql)
if not users:
logger.info("call fetch_helper(), no record")
else:
logger.info("call fetch_helper(), got %d record(s)", len(users))
for row in users:
user_id_set.add(row['id'])
def from_user_register():
sql = """
select distinct(user_id) from `db`.`user_register_{}`
union select distinct(user_id) from `db`.`user_register_{}`
union select distinct(user_id) from `db`.`user_register_{}`
""".format(format_date(-1), format_date(-2), format_date(-3))
users = fetch_helper(user_register, sql)
if not users:
logger.info("call fetch_helper(), no record")
else:
logger.info("call fetch_helper(), got %d record(s)", len(users))
for row in users:
user_id_set.add(row['user_id'])
def from_user_action_log():
sql = """
select distinct(user_id) from `db`.`user_action_log_{}`
union select distinct(user_id) from `db`.`user_action_log_{}`
union select distinct(user_id) from `db`.`user_action_log_{}`
""".format(format_date(-1), format_date(-2), format_date(-3))
users = fetch_helper(user_action_log, sql)
if not users:
logger.info("call fetch_helper(), no record")
else:
logger.info("call fetch_helper(), got %d record(s)", len(users))
for row in users:
user_id_set.add(row['user_id'])
if __name__ == '__main__':
init_logger(logger)
logger.info("begin task")
# 清空表
truncate_table_helper()
# 清洗数据
from_push_stat()
logger.info("after from_push_stat(), size: %d", len(user_id_set))
from_user()
logger.info("after from_user(), size: %d", len(user_id_set))
from_user_register()
logger.info("after from_user_register(), size: %d", len(user_id_set))
from_user_action_log()
logger.info("after from_user_action_log(), size: %d", len(user_id_set))
# 批量插入数据
batch_insert_helper(user_id_set)
logger.info("end task")[Python] kafka 使用
**环境：**Python 2.7.14/kafka-python 1.4.2
**Tag：**kafka 生产者、消费者
**参考：**http://kafka-python.readthedocs.io/en/master/usage.html
消费者
from kafka import KafkaConsumer
def consume():
# To consume latest messages and auto-commit offsets
consumer = KafkaConsumer('test',
group_id='test-group',
bootstrap_servers=['192.168.2.99:9092'],
api_version=(0, 10))
for message in consumer:
# message value and key are raw bytes -- decode if necessary!
# e.g., for unicode: `message.value.decode('utf-8')`
print("%s:%d:%d: key=%s value=%s" % (message.topic, message.partition,
message.offset, message.key,
message.value))
if __name__ == '__main__':
consume()生产者
from kafka import KafkaProducer
from kafka.errors import KafkaError
import json
import sys
def on_send_success(record_metadata):
print(record_metadata.topic, record_metadata.partition, record_metadata.offset)
def on_send_error(excp):
print('I am an errback', str(exc_info=excp))
# handle exception
producer = KafkaProducer(bootstrap_servers=['192.168.2.99:9092'],
api_version=(0, 10),
max_block_ms=10000,
retries=2)
def produce():
for i in range(3):
message = {
'id': i,
'msg': 'hello world',
}
# produce asynchronously with callbacks
# produce keyed messages to enable hashed partitioning
producer.send('test', key='bingo', value=json.dumps(message)).add_callback(
on_send_success).add_errback(on_send_error)
# un-keyed messages
producer.send('test', json.dumps(message)).add_callback(on_send_success).add_errback(
on_send_error)
# block until all async messages are sent
producer.flush()
if __name__ == '__main__':
produce()输出
$ python kafka_producer.py
('test', 0, 132)
('test', 0, 133)
('test', 0, 134)
('test', 0, 135)
('test', 0, 136)
('test', 0, 137)$ python kafka_consumer.py
test:0:132: key=bingo value={"msg": "hello world", "id": 0}
test:0:133: key=None value={"msg": "hello world", "id": 0}
test:0:134: key=bingo value={"msg": "hello world", "id": 1}
test:0:135: key=None value={"msg": "hello world", "id": 1}
test:0:136: key=bingo value={"msg": "hello world", "id": 2}
test:0:137: key=None value={"msg": "hello world", "id": 2}[Python] YAML 配置文件
**环境：**Python 2.7.14/PyYAML 3.12
**依赖库：**pip install pyyaml
# coding: utf8
import os
import yaml
import time
from os import path
class DynFileLoader(object):
def __init__(self, file_path, detect_interval=10):
if not path.exists(file_path):
raise IOError('{} not existed'.format(file_path))
self._detect_interval = detect_interval
self._file_path = file_path
self._file_last_mtime = None
self._file_content = None
self._file_last_load_time = None
self._reload()
def _reload(self):
with open(self._file_path) as f:
now = int(time.time())
self._file_content = f.read()
self._file_last_mtime = now
self._file_last_load_time = now
def _is_file_modified(self):
return path.getmtime(self._file_path) > self._file_last_mtime
def _should_reload(self):
now = int(time.time())
if now - self._file_last_load_time > self._detect_interval:
return self._is_file_modified()
else:
return False
def get_content(self):
if self._should_reload():
self._reload()
return self._file_content
class DynYamlConfig(DynFileLoader):
def __init__(self, file_path, detect_interval=10):
self._yaml_map = {}
DynFileLoader.__init__(self, file_path, detect_interval)
def _reload(self):
with open(self._file_path) as f:
now = int(time.time())
self._yaml_map = yaml.safe_load(f)
self._file_last_mtime = now
self._file_last_load_time = now
def get_content(self):
if self._should_reload():
self._reload()
return self._yaml_map
def get_value(self, key, default=None):
config = self.get_content()
if not config:
return default
return config.get(key, default)
if __name__ == '__main__':
conf = DynYamlConfig('dummy.yml')
content = conf.get_content()
print(content)
item = conf.get_value("product")['item']
print(item)
numbers = conf.get_value("numbers")
print(numbers)
item = conf.get_value("food")['fruit']['item']
print(item)输出
{'food': {'fruit': {'item': 'apple'}}, 'product': {'item': 'hello'}, 'numbers': [1, 2, 3, 4]}
hello
[1, 2, 3, 4]
apple[Python] HTTP GET/POST 请求
urllib2
# coding = utf-8
import urllib2
import json
import sys
reload(sys)
sys.setdefaultencoding('utf-8')
def get(url):
resp = urllib2.urlopen(url=url, timeout=10)
return resp.read()
def post(url, data):
resp = urllib2.urlopen(url=url, data=data, timeout=10)
return resp.read()
if __name__ == '__main__':
data1 = get('http://45.77.40.154:9999/admin_stat/product')
print(data1)
payload = {
'product': 'ahihi'
}
data2 = post('http://45.77.40.154:9999/admin_stat/category',
json.dumps(payload))
print(data2)输出
{"message": "success", "data": [{"name": "\u5934\u6761\u4ea7\u54c1", "value": "lsb"}, {"name": "\u5c0f\u8bf4\u6f2b\u753b", "value": "ahihi"}]}
{"message": "success", "data": [{"description": "total product data", "children": [], "name": "\u4ea7\u54c1\u603b\u4f53\u6570\u636e",
"data_cat": "total_product_data,"}]}requests
# coding = utf-8
import requests
import sys
import json
reload(sys)
sys.setdefaultencoding('utf-8')
RETRY_TIMES = 1
REQUEST_TIMEOUT = 3
http_session = requests.Session()
def common_request(url, payload):
retry_times = 0
resp = None
while retry_times < RETRY_TIMES:
try:
resp = http_session.post(
url, data=json.dumps(payload), timeout=REQUEST_TIMEOUT)
break
except Exception as ex:
print("common_request post error: %s, url=%s" % (ex, url))
retry_times += 1
if (resp is not None) and (resp.status_code == 200):
r = resp.json()
result = r.get('data', {})
print("return resp result_len=%d" % (len(result)))
return result
else:
print("common_request post error! url=%s, payload=%s" % (url, payload))
return None
if __name__ == '__main__':
r = requests.get('http://45.77.40.154:9999/admin_stat/product')
print(r.content)
payload = {'product': 'ahihi'}
r = requests.post('http://45.77.40.154:9999/admin_stat/category',
json.dumps(payload))
print('URL: ', r.url)
print('HEADERS: ', r.headers)
print('Content-Type: ', r.headers.get('content-type'))
print('CODE: ', r.status_code)
print(r.content)
result = common_request('http://45.77.40.154:9999/admin_stat/category',
payload)
print(result)输出
{"message": "success", "data": [{"name": "\u5934\u6761\u53f7\u4f5c\u8005", "value": "top_author"}, {"name": "\u5934\u6761\u4ea7\u54c1", "value": "lsb"}, {"name": "\u5c0f\u8bf4\u6f2b\u753b", "value": "novel&comic"}]}
('URL: ', u'http://45.77.40.154:9999/admin_stat/category')
('HEADERS: ', {'Date': 'Tue, 29 May 2018 03:29:47 GMT', 'Content-Length': '171', 'Content-Type': 'application/json', 'Server': 'Werkzeug/0.12.2 Python/2.7.5'})
('Content-Type: ', 'application/json')
('CODE: ', 200)
{"message": "success", "data": [{"description": "total product data", "children": [], "name": "\u4ea7\u54c1\u603b\u4f53\u6570\u636e",
"data_cat": "total_product_data,"}]}
return resp result_len=1
[{u'data_cat': u'total_product_data,', u'description': u'total product data', u'name': u'\u4ea7\u54c1\u603b\u4f53\u6570\u636e', u'children': []}][Python] Flask RESTful
**环境：**Python 2.7.14/Flask 0.11.1/Flask-RESTful 0.3.5/Flask-SQLAlchemy 2.2
# -*- coding:utf-8 -*-
from flask import Flask
from flask_restful import Api
from flask_restful import Resource
import os
import sys
sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
reload(sys)
sys.setdefaultencoding('utf-8')
class IndexView(Resource):
def post(self):
return {'message': 'error! please use http get'}
def get(self):
return {'message': 'hello world'}
if __name__ == '__main__':
app = Flask(__name__)
api = Api(app)
api.add_resource(IndexView, '/index')
app.run(host='0.0.0.0', port=12345, debug=True)输出
[root@~]# python app.py
* Running on http://0.0.0.0:12345/ (Press CTRL+C to quit)
* Restarting with stat
* Debugger is active!
* Debugger PIN: 293-571-458
127.0.0.1 - - [25/May/2018 09:34:49] "GET /index HTTP/1.1" 200 -[root@~]# curl http://0.0.0.0:12345/index
{
"message": "hello world"
}[Python] WSGI 服务器以及中间件
**环境：**Python 2.7.4
源码：点此下载
from wsgiref.simple_server import make_server
URL_PATTERNS = (
('hi/', 'say_hi'),
('hello/', 'say_hello'),
)
# 自定义中间件
class Dispatcher(object):
def _match(self, path):
path = path.split('/')[1]
for url, app in URL_PATTERNS:
if path in url:
return app
def __call__(self, environ, start_response):
path = environ.get('PATH_INFO', '/')
app = self._match(path)
if app:
app = globals()[app]
return app(environ, start_response)
else:
start_response("404 NOT FOUND", [('Content-type', 'text/plain')])
return ["Not Found!"]
def say_hi(environ, start_response):
start_response("200 OK", [('Content-type', 'text/html')])
return ["Hi!"]
def say_hello(environ, start_response):
start_response("200 OK", [('Content-type', 'text/html')])
return ["Hello!"]
app = Dispatcher()
httpd = make_server('', 8000, app)
print "Serving on port 8000..."
httpd.serve_forever()输出
Serving on port 8000...
('middleware, uri: ', '/hi')
127.0.0.1 - - [28/May/2018 00:06:03] "GET /hi HTTP/1.1" 200 3
('middleware, uri: ', '/hello')
127.0.0.1 - - [28/May/2018 00:06:07] "GET /hello HTTP/1.1" 200 6
('middleware, uri: ', '/haha')
127.0.0.1 - - [28/May/2018 00:06:15] "GET /haha HTTP/1.1" 404 10$ curl http://127.0.0.1:8000/hi -s
Hi!
$ curl http://127.0.0.1:8000/hello -s
Hello!
$ curl http://127.0.0.1:8000/haha -s
Not Found![Python] 微信报警
**环境：**Python 2.7.14
源码：点此下载
**功能：**将服务异常信息通过微信企业号 api 发送给运维员工企业微信
# coding = utf-8
import urllib2
import copy
import time
import json
import sys
import getopt
ACCESS_TOKEN_URL = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=your-corpid&corpsecret=your-corpsecret"
SEND_MESSAGE_URL = "https://qyapi.weixin.qq.com/cgi-bin/message/send?access_token="
MSG_TEMPLATE = {
"msgtype": "text",
"agentid": 1,
"text": {
"content": "no message set"
},
"safe": 0
}
class Wechat(object):
def __init__(self):
self.last_get_token_time = 0
self.token_expire = 0
self.token = None
def _get(self, url):
resp = urllib2.urlopen(url=url, timeout=10)
return resp.read()
def _post(self, url, data):
resp = urllib2.urlopen(url=url, data=data, timeout=10)
return resp.read()
def _get_access_token(self):
data = self._get(ACCESS_TOKEN_URL)
if data == None:
print("request wechat server falied")
return
resp = json.loads(data)
if resp == None:
print("request wechat server falied")
if resp["errcode"] == 0:
self.token = resp["access_token"]
self.last_get_token_time = int(time.time())
self.token_expire = resp["expires_in"]
else:
print("get wechat access token error, msg: %s", resp["errmsg"])
def send_message(self, toparty=None, touser=None, msg="no msg set"):
if not self.is_token_valid():
self._get_access_token()
body = copy.deepcopy(MSG_TEMPLATE)
text = body.setdefault("text", {})
text["content"] = msg
if toparty != None:
body["toparty"] = toparty
if touser != None:
body["touser"] = touser
url = SEND_MESSAGE_URL + self.token
data = self._post(url, json.dumps(body))
if data == None:
print("request wechat server falied")
return
resp = json.loads(data)
if resp == None:
print("request wechat server falied")
elif resp["errcode"] != 0:
print("get wechat access token error, msg: %s", resp["errmsg"])
else:
pass
def is_token_valid(self):
if self.token == None:
return False
elif (int(time.time()) - self.last_get_token_time) > (self.token_expire - 100):
return False
else:
return True
wechat = Wechat()
def notify(userids, message):
if userids is None:
notify_all(message)
else:
notify_user(userids, message)
def notify_all(message):
wechat.send_message(toparty="2", msg=message)
def notify_user(userids, message):
users = "|".join(userids)
wechat.send_message(touser=users, msg=message)
def send_message(msg):
wechat.send_message(msg)
def usage(e):
print "python wechat_alter.py -m \"test message\" -u \"lvfei,XieJianHe\""
if e != None:
print str(e)
if __name__ == '__main__':
try:
opts, args = getopt.getopt(sys.argv[1:], "m:u:")
message = None
users = None
for op, value in opts:
if op == "-m":
message = value
elif op == "-u":
users = value.split(",")
else:
usage(None)
sys.exit()
if message == None:
raise Exception("-m must be setted")
if users != None:
notify_user(users, message)
else:
notify_all(message)
print "Message send success"
except Exception, e:
usage(e)
sys.exit()[Python] IP 定位
对于客户端使用代理，按照代理 IP 进行处理。服务端获取客户端 IP，使用
www.ip.cn提供的 IP 定位服务获取客户端接入的位置信息。
# -*- coding:utf-8 -*-
from flask_restful import Resource
from flask import request
from common.common import logger
import common.db_utility as db_utility
import json
from bs4 import BeautifulSoup
import requests
def get_ip_info(ip):
url = 'http://www.ip.cn/index.php?ip={0}'.format(ip)
headers = {
'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
'Accept-Encoding': 'gzip, deflate, sdch',
'Accept-Language': 'zh-CN,zh;q=0.8,en;q=0.6',
'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.102 Safari/537.36',
'Referer': 'http://www.ip.cn/',
'Connection': 'keep-alive',
'Host': 'www.ip.cn',
}
data = {}
try:
r = requests.get(url, headers=headers, timeout=30)
soup = BeautifulSoup(r.content, "html.parser")
s = soup.find(name='div', attrs={"id": "result"})
data['errorcode'] = 0
data['errormsg'] = 'acquire location info success'
data['ip'] = s.find_all(name="code")[0].get_text()
data['location'] = s.find_all(name="code")[1].get_text()
except Exception as e:
logger.error(e)
data['errorcode'] = 0
data['errormsg'] = 'acquire location info failed'
logger.debug("client location info: %s", data)
return data
class TestView(Resource):
def post(self):
ip = request.headers.getlist(
"X-Forwarded-For")[0] if request.headers.getlist("X-Forwarded-For") else request.remote.addr
logger.debug("client address: %s, visit: %s", ip, request.base_url)
return get_ip_info(ip)
def get(self):
ip = request.headers.getlist(
"X-Forwarded-For")[0] if request.headers.getlist("X-Forwarded-For") else request.remote.addr
logger.debug("client address: %s, visit: %s", ip, request.base_url)
return get_ip_info(ip)输出
{
"errorcode": 0,
"errormsg": "acquire location info success",
"location": "广东省深圳市 联通",
"ip": "163.125.210.209"
}如果使用美国代理，输出如下
{
"errorcode": 0,
"errormsg": "acquire location info success",
"location": "美国 ",
"ip": "45.62.102.71"
}[Python] 发送邮件
import smtplib
from email.mime.text import MIMEText
subject = "Test"
content = "hello world"
sender = "service@i-deer.com"
password = "123456"
receivers = ["c.r2009@163.com"]
for receiver in receivers:
message = MIMEText(content, "html", "utf-8")
message["From"] = sender
message["To"] = receiver
message["Subject"] = subject
# enale SSL
smtp = smtplib.SMTP_SSL('smtp.i-deer.com', 465)
# disable SSL
#smtp = smtplib.SMTP()
#smtp.connect('smtp.i-deer.com', 25)
smtp.login(sender, password)
smtp.sendmail(sender, [receiver], message.as_string())
smtp.close()[Python] websocket client
import websocket
try:
import thread
except ImportError:
import _thread as thread
import time
def on_message(ws, message):
print(message)
def on_error(ws, error):
print(error)
def on_close(ws):
print("### closed ###")
def on_open(ws):
def run(*args):
while 1:
time.sleep(1)
# do something here
thread.start_new_thread(run, ())
if __name__ == "__main__":
#websocket.enableTrace(True)
ws = websocket.WebSocketApp("ws://127.0.0.1:8081/ws",
on_message = on_message,
on_error = on_error,
on_close = on_close)
ws.on_open = on_open
ws.run_forever()[Python] doc 转换为 docx
windows
通过 pip 安装依赖：
pip install pywin32
import os
from win32com import client
def doc_to_docx(path):
if os.path.splitext(path)[1] == ".doc":
word = client.Dispatch('Word.Application')
doc = word.Documents.Open(path)
doc.SaveAs(os.path.splitext(path)[0]+".docx", 16)
doc.Close()
word.Quit()
def find_file(path, ext, file_list=[]):
dir = os.listdir(path)
for i in dir:
i = os.path.join(path, i)
if os.path.isdir(i):
find_file(i, ext, file_list)
else:
if ext == os.path.splitext(i)[1]:
file_list.append(i)
return file_list
dir_path = "e:/tmp"
ext = ".doc"
file_list = find_file(dir_path, ext)
for file in file_list:
doc_to_docx(file)linux(centos)
通过 yum 安装依赖：
yum install libreoffice -y
import subprocess
import os
def find_file(path, ext, file_list=[]):
dir = os.listdir(path)
for i in dir:
i = os.path.join(path, i)
if os.path.isdir(i):
find_file(i, ext, file_list)
else:
if ext == os.path.splitext(i)[1]:
file_list.append(i)
return file_list
dir_path = "/root/tmp"
ext = ".doc"
file_list = find_file(dir_path, ext)
for file in file_list:
subprocess.check_output(["soffice", "--headless",
"--invisible", "--convert-to",
"docx", file, "--outdir", "/root/tmp"])[Python] 比特币公钥生成地址
#!/usr/bin/env python
# https://en.bitcoin.it/wiki/Protocol_documentation#Addresses
import hashlib
import base58
# ECDSA bitcoin Public Key
#pubkey = '0450863ad64a87ae8a2fe83c1af1a8403cb53f53e486d8511dad8a04887e5b23522cd470243453a299fa9e77237716103abc11a1df38855ed6f2ee187e9c582ba6'
pubkey = '0334008297092d21e1f8a13b5ed7bada18356fb9b96d607eaceb1e06ecd87b0f3c'
# See 'compressed form' at https://en.bitcoin.it/wiki/Protocol_documentation#Signatures
compress_pubkey = False
def hash160(hex_str):
sha = hashlib.sha256()
rip = hashlib.new('ripemd160')
sha.update(hex_str)
rip.update(sha.digest())
print("key_hash = \t" + rip.hexdigest())
return rip.hexdigest() # .hexdigest() is hex ASCII
if (compress_pubkey):
if (ord(bytearray.fromhex(pubkey[-2:])) % 2 == 0):
pubkey_compressed = '02'
else:
pubkey_compressed = '03'
pubkey_compressed += pubkey[2:66]
hex_str = bytearray.fromhex(pubkey_compressed)
else:
hex_str = bytearray.fromhex(pubkey)
# Obtain key:
key_hash = '00' + hash160(hex_str)
# Obtain signature:
sha = hashlib.sha256()
sha.update(bytearray.fromhex(key_hash))
checksum = sha.digest()
sha = hashlib.sha256()
sha.update(checksum)
checksum = sha.hexdigest()[0:8]
print("checksum = \t" + sha.hexdigest())
print("key_hash + checksum = \t" + key_hash + ' ' + checksum)
print("bitcoin address = \t" +
base58.b58encode(bytes(bytearray.fromhex(key_hash + checksum))))输出
key_hash = 218e8a0f6f1d68af0485e39e05458e6d8b6a8086
checksum = 2887135cfceed2c7a9de6ee3c73702177dae22f0cc7a64f2b1f5f716fcb88446
key_hash + checksum = 00218e8a0f6f1d68af0485e39e05458e6d8b6a8086 2887135c
bitcoin address = 144S48oJhbg6hDDSDSwZSe45ieTDkxhyko[Lua] 求最大值
function maximum(a)
local mi = 1 -- maximum index
local mv = a[mi] -- maximum value
for i, val in ipairs(a) do
if val > mv then
mi = i
mv = val
end
end
return mi, mv
end
print(maximum({12, 99, 28, 49, 92, 5}))输出
2 99[Lua] 解包 unpack
function unpack(t, i)
i = i or 1
if t[i] ~= nil then
return t[i], unpack(t, i + 1)
end
end
local t = {'h', 'e', 'l', 'l', 'o'}
print(unpack(t))
local t2 = {unpack(t, 3)}
for i, v in ipairs(t2) do
print(i, v)
end输出
h e l l o
1 l
2 l
3 o[Lua] 不定参数与格式化
function fwrite(fmt, ...)
return io.write(string.format(fmt, unpack(arg)))
end
fwrite("greetings: %s\n", "hello")
fwrite("%s, %s%d\n", "hello", "dudebing", 99)输出
greetings: hello
hello, dudebing99[Solidity] 以太坊合约示例：hello world
Solidity 合约脚本如下，点此下载
pragma solidity ^0.4.11;
contract HelloWorld
{
address creator;
string greeting;
constructor(string _greeting) public
{
creator = msg.sender;
greeting = _greeting;
}
function greet() public view returns (string)
{
return greeting;
}
function setGreeting(string _newgreeting) public
{
greeting = _newgreeting;
}
// Standard kill() function to recover funds
function kill() public
{
if (msg.sender == creator)
{
// kills this contract and sends remaining funds back to creator
selfdestruct(creator);
}
}
}使用 SolC 编译上述脚本
root:ethereum# solc --optimize --abi --bin helloworld.sol
======= helloworld.sol:HelloWorld =======
Binary:
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
Contract JSON ABI
[{"constant":false,"inputs":[],"name":"kill","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_newgreeting","type":"string"}],"name":"setGreeting","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"greet","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[{"name":"_greeting","type":"string"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"}]调用合约的 js 脚本【同步】，点此下载
let Web3 = require('web3');
let web3;
if (typeof web3 !== 'undefined') {
web3 = new Web3(web3.currentProvider);
} else {
// set the provider you want from Web3.providers
web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
}
abi =
[{"constant":false,"inputs":[],"name":"kill","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_newgreeting","type":"string"}],"name":"setGreeting","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"greet","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[{"name":"_greeting","type":"string"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"}];
hex =
"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";
helloworldContract = web3.eth.contract(abi);
helloworld = helloworldContract.new('hello world', {from:web3.eth.accounts[0], data:hex, gas:3000000});
//console.log(helloworld);
recpt = web3.eth.getTransactionReceipt(helloworld.transactionHash);
//console.log(recpt);
contract_ = helloworldContract.at(recpt.contractAddress);
//console.log(contract_);
console.log(contract_.greet.call());
// 调用 setGreeting()，修改问候语
//contract_.setGreeting.sendTransaction('bala bala', {from:web3.eth.accounts[0], gas:3000000})
//console.log(contract_.greet.call());
process.exit(0);调用合约的 js 脚本【异步】，点此下载
let Web3 = require('web3');
let web3;
if (typeof web3 !== 'undefined') {
web3 = new Web3(web3.currentProvider);
} else {
// set the provider you want from Web3.providers
web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
}
var _greeting = 'hello world' ;
var helloworldContract =
web3.eth.contract([{"constant":false,"inputs":[],"name":"kill","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_newgreeting","type":"string"}],"name":"setGreeting","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"greet","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[{"name":"_greeting","type":"string"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"}]);
var helloworld = helloworldContract.new(
_greeting,
{
from: web3.eth.accounts[3],
data:
'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',
gas: '3000000'
}, function (e, contract){
recpt = web3.eth.getTransactionReceipt(contract.transactionHash);
contract_ = helloworldContract.at(recpt.contractAddress);
console.log(contract_.greet.call());
//contract_.setGreeting.sendTransaction('bala bala', {from:web3.eth.accounts[0], gas:3000000})
//console.log(samplecontract.greet.call());
process.exit(0);
})调用 node 执行脚本
root:ethereum# node helloworld.js
hello world[Solidity] 以太坊合约示例：存储
Solidity 合约脚本如下，点此下载
pragma solidity ^0.4.11;
contract Sample {
uint public value;
constructor(uint v) public {
value = v;
}
function set(uint v) public {
value = v;
}
function get() public view returns (uint) {
return value;
}
}使用 SolC 编译上述脚本
root:ethereum# solc --optimize --abi --bin sample.sol
======= sample.sol:Sample =======
Binary:
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
Contract JSON ABI
[{"constant":true,"inputs":[],"name":"value","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"v","type":"uint256"}],"name":"set","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"get","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[{"name":"v","type":"uint256"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"}]调用合约的 js 脚本，点此下载
let Web3 = require('web3');
let web3;
if (typeof web3 !== 'undefined') {
web3 = new Web3(web3.currentProvider);
} else {
// set the provider you want from Web3.providers
web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
}
abi = [{"constant":true,"inputs":[],"name":"value","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"v","type":"uint256"}],"name":"set","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"get","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[{"name":"v","type":"uint256"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"}];
hex = "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";
sample = web3.eth.contract(abi);
thesample = sample.new(99, {from:web3.eth.accounts[0], data:hex, gas:3000000});
//console.log(thesample);
samplerecpt = web3.eth.getTransactionReceipt(thesample.transactionHash);
//console.log(samplerecpt);
samplecontract = sample.at(samplerecpt.contractAddress);
//console.log(samplecontract);
console.log(samplecontract.get.call());
console.log(samplecontract.set.sendTransaction(1001, {from:web3.eth.accounts[0], gas:3000000}));
console.log(samplecontract.get.call());
process.exit(0);调用 node 执行脚本
root:ethereum# node sample.js
BigNumber { s: 1, e: 1, c: [ 99 ] }
0x0b06f2da58bd421d6db88ec2b25144491eafa5f9f53573e5783b9dd4da91c510
BigNumber { s: 1, e: 3, c: [ 1001 ] }[Solidity] 以太坊合约示例：子货币
合约创建者拥有铸币权，创建合约时，构造函数设置铸币者
铸币者可以调用 mint() 实现铸币
不同用户可以调用 send() 实现自货币之间的转账（转出账户余额足够即可）
可以调用 kill() 实现合约销毁，并将余额返回给铸币者
调用 watch() 监听事件，用来辅助调试、完成上层业务或记录日志
Solidity 合约脚本如下，点此下载
pragma solidity ^0.4.21;
contract Coin {
address public minter;
mapping (address => uint) public balances;
event Sent(address from, address to, uint amount);
constructor() public {
minter = msg.sender;
}
function mint(address receiver, uint amount) public {
if (msg.sender != minter) return;
balances[receiver] += amount;
}
function send(address receiver, uint amount) public {
if (balances[msg.sender] < amount) return;
balances[msg.sender] -= amount;
balances[receiver] += amount;
emit Sent(msg.sender, receiver, amount);
}
function kill() public
{
if (msg.sender == minter)
{
// kills this contract and sends remaining funds back to creator
selfdestruct(minter);
}
}
}使用 SolC 编译上述脚本
root@iZwz978rorvlg75nct99l1Z:~/eth# solc --optimize --abi --bin sub_currency.sol
======= sub_currency.sol:Coin =======
Binary:
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
Contract JSON ABI
[{"constant":true,"inputs":[],"name":"minter","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"balances","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"receiver","type":"address"},{"name":"amount","type":"uint256"}],"name":"mint","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[],"name":"kill","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"receiver","type":"address"},{"name":"amount","type":"uint256"}],"name":"send","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"inputs":[],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":false,"name":"from","type":"address"},{"indexed":false,"name":"to","type":"address"},{"indexed":false,"name":"amount","type":"uint256"}],"name":"Sent","type":"event"}]调用合约的 js 脚本，点此下载
**功能：**铸币、转账
let Web3 = require('web3');
let web3;
if (typeof web3 !== 'undefined') {
web3 = new Web3(web3.currentProvider);
} else {
// set the provider you want from Web3.providers
web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
}
abi = [{"constant":true,"inputs":[],"name":"minter","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"balances","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"receiver","type":"address"},{"name":"amount","type":"uint256"}],"name":"mint","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[],"name":"kill","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"receiver","type":"address"},{"name":"amount","type":"uint256"}],"name":"send","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"inputs":[],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":false,"name":"from","type":"address"},{"indexed":false,"name":"to","type":"address"},{"indexed":false,"name":"amount","type":"uint256"}],"name":"Sent","type":"event"}];
subcurrencyContract = web3.eth.contract(abi);
subcurrency = subcurrencyContract.new({from:web3.eth.accounts[0], data:hex, gas:3000000});
//console.log(subcurrency);
recpt = web3.eth.getTransactionReceipt(subcurrency.transactionHash);
//console.log(recpt);
contract_ = subcurrencyContract.at(recpt.contractAddress);
//console.log(contract_);
console.log(recpt.contractAddress);
contract_.Sent().watch(function(error, result) {
if (!error) {
console.log("\nCoin transfer: " + result.args.amount +
" coins were sent from " + result.args.from +
" to " + result.args.to + ".");
console.log("Sender: " + contract_.balances.call(result.args.from) +
", Receiver: " + contract_.balances.call(result.args.to) + "\n");
}
})
console.log("mint's hash: ", contract_.mint(web3.eth.accounts[0], 666, {from: web3.eth.accounts[0],
gas:3000000}));
console.log("minter's balance: ", contract_.balances.call(web3.eth.accounts[0]));
console.log("mint's hash ", contract_.send(web3.eth.accounts[3], 99, {from: web3.eth.accounts[0],
gas:3000000}));
console.log("minter's balance: ", contract_.balances.call(web3.eth.accounts[0]));
console.log("receiver's balance: ", contract_.balances.call(web3.eth.accounts[3]));
setTimeout(function() {
process.exit(0);
}, 5000);调用 node 执行脚本
**合约地址：**0x6c26a63139497d5fd5f1acbb4a35e0b0798b9fb2
root:ethereum# node subcurrency.js
0x6c26a63139497d5fd5f1acbb4a35e0b0798b9fb2
mint's hash: 0xcb51b7dd044daee96a1a2060526c848589387d42dfc070ef8b677aa2284caedd
minter's balance: BigNumber { s: 1, e: 2, c: [ 666 ] }
mint's hash 0x2b67a507a56aaee93380a211d69a2da7349382c5d43d460badbfa2a16f835df7
minter's balance: BigNumber { s: 1, e: 2, c: [ 567 ] }
receiver's balance: BigNumber { s: 1, e: 1, c: [ 99 ] }
Coin transfer: 99 coins were sent from 0x2f3efd9475fb969eecfdade75a1dae02dbd92e25 to 0xc186ac87182106ff972adcc2952aae95716c9c41.
Sender: 567, Receiver: 99调用合约的 js 脚本，点此下载
**功能：**铸币、转账、销毁合约
let Web3 = require('web3');
let web3;
if (typeof web3 !== 'undefined') {
web3 = new Web3(web3.currentProvider);
} else {
// set the provider you want from Web3.providers
web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
}
abi = [{"constant":true,"inputs":[],"name":"minter","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"balances","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"receiver","type":"address"},{"name":"amount","type":"uint256"}],"name":"mint","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[],"name":"kill","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"receiver","type":"address"},{"name":"amount","type":"uint256"}],"name":"send","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"inputs":[],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":false,"name":"from","type":"address"},{"indexed":false,"name":"to","type":"address"},{"indexed":false,"name":"amount","type":"uint256"}],"name":"Sent","type":"event"}];
subcurrencyContract = web3.eth.contract(abi);
// 根据上一个脚本运行结果获取合约地址
contract_ = subcurrencyContract.at('0x6c26a63139497d5fd5f1acbb4a35e0b0798b9fb2');
//console.log(contract_);
contract_.Sent().watch(function(error, result) {
if (!error) {
console.log("\nCoin transfer: " + result.args.amount +
" coins were sent from " + result.args.from +
" to " + result.args.to + ".");
console.log("Sender: " + contract_.balances.call(result.args.from) +
", Receiver: " + contract_.balances.call(result.args.to) + "\n");
}
})
console.log("mint's hash: ", contract_.mint(web3.eth.accounts[0], 666, {from: web3.eth.accounts[0], gas:3000000}));
console.log("minter's balance: ", contract_.balances.call(web3.eth.accounts[0]));
console.log("mint's hash ", contract_.send(web3.eth.accounts[3], 99, {from: web3.eth.accounts[0], gas:3000000}));
console.log("minter's balance: ", contract_.balances.call(web3.eth.accounts[0]));
console.log("receiver's balance: ", contract_.balances.call(web3.eth.accounts[3]));
console.log("kill's hash: ", contract_.kill({from: web3.eth.accounts[0], gas:3000000}));
console.log("minter's balance: ", contract_.balances.call(web3.eth.accounts[0]));
console.log("receiver's balance: ", contract_.balances.call(web3.eth.accounts[3]));
setTimeout(function() {
process.exit(0);
}, 5000);调用 node 执行脚本
root:ethereum# node subcurrency2.js
mint's hash: 0xaa84ad2811d2a38823ac0b5b8ea987202fe972b216a95abfe2b82b1992ed0685
minter's balance: BigNumber { s: 1, e: 3, c: [ 1233 ] }
mint's hash 0xdc24bbda345bfd4e2a5cba4c82dabfdc0441dd4be0892ad57e5ada940339bcfe
minter's balance: BigNumber { s: 1, e: 3, c: [ 1134 ] }
receiver's balance: BigNumber { s: 1, e: 2, c: [ 198 ] }
kill's hash: 0xa69ff21e1774552671c7a444abe957a9ae25ae7f30e3b5ddbfcb7a6a0a6b121f
minter's balance: BigNumber { s: 1, e: 0, c: [ 0 ] }
receiver's balance: BigNumber { s: 1, e: 0, c: [ 0 ] }销毁合约后，再次调用 node 执行脚本
mint's hash: 0xc6f64308528ffa74d585385d7553fbfc36fa514bbec577a311752e2eedc45c14
minter's balance: BigNumber { s: 1, e: 0, c: [ 0 ] }
mint's hash 0xcf64ab8cf1096ef1b40d4982d169d5889aa529ab9e1c06a9b0a185286b1c5910
minter's balance: BigNumber { s: 1, e: 0, c: [ 0 ] }
receiver's balance: BigNumber { s: 1, e: 0, c: [ 0 ] }
kill's hash: 0x501f3a707bb36b1c2216f90f382ac7ec11de2277b1c200cb5fd104ca02dd2c37
minter's balance: BigNumber { s: 1, e: 0, c: [ 0 ] }
receiver's balance: BigNumber { s: 1, e: 0, c: [ 0 ] }[Solidity] 以太坊合约示例：币安 Token
**参考资料：**https://etherscan.io/address/0xB8c77482e45F1F44dE1745F52C74426C631bDD52#code
Solidity 合约脚本如下，点此下载
pragma solidity ^0.4.8;
/**
* Math operations with safety checks
*/
contract SafeMath {
function safeMul(uint256 a, uint256 b) internal returns (uint256) {
uint256 c = a * b;
assert(a == 0 || c / a == b);
return c;
}
function safeDiv(uint256 a, uint256 b) internal returns (uint256) {
assert(b > 0);
uint256 c = a / b;
assert(a == b * c + a % b);
return c;
}
function safeSub(uint256 a, uint256 b) internal returns (uint256) {
assert(b <= a);
return a - b;
}
function safeAdd(uint256 a, uint256 b) internal returns (uint256) {
uint256 c = a + b;
assert(c>=a && c>=b);
return c;
}
function assert(bool assertion) internal {
if (!assertion) {
throw;
}
}
}
contract BNB is SafeMath{
string public name;
string public symbol;
uint8 public decimals;
uint256 public totalSupply;
address public owner;
/* This creates an array with all balances */
mapping (address => uint256) public balanceOf;
mapping (address => uint256) public freezeOf;
mapping (address => mapping (address => uint256)) public allowance;
/* This generates a public event on the blockchain that will notify clients */
event Transfer(address indexed from, address indexed to, uint256 value);
/* This notifies clients about the amount burnt */
event Burn(address indexed from, uint256 value);
/* This notifies clients about the amount frozen */
event Freeze(address indexed from, uint256 value);
/* This notifies clients about the amount unfrozen */
event Unfreeze(address indexed from, uint256 value);
/* Initializes contract with initial supply tokens to the creator of the contract */
function BNB(
uint256 initialSupply,
string tokenName,
uint8 decimalUnits,
string tokenSymbol
) {
balanceOf[msg.sender] = initialSupply; // Give the creator all initial tokens
totalSupply = initialSupply; // Update total supply
name = tokenName; // Set the name for display purposes
symbol = tokenSymbol; // Set the symbol for display purposes
decimals = decimalUnits; // Amount of decimals for display purposes
owner = msg.sender;
}
/* Send coins */
function transfer(address _to, uint256 _value) {
if (_to == 0x0) throw; // Prevent transfer to 0x0 address. Use burn() instead
if (_value <= 0) throw;
if (balanceOf[msg.sender] < _value) throw; // Check if the sender has enough
if (balanceOf[_to] + _value < balanceOf[_to]) throw; // Check for overflows
balanceOf[msg.sender] = SafeMath.safeSub(balanceOf[msg.sender], _value); // Subtract from the sender
balanceOf[_to] = SafeMath.safeAdd(balanceOf[_to], _value); // Add the same to the recipient
Transfer(msg.sender, _to, _value); // Notify anyone listening that this transfer took place
}
/* Allow another contract to spend some tokens in your behalf */
function approve(address _spender, uint256 _value)
returns (bool success) {
if (_value <= 0) throw;
allowance[msg.sender][_spender] = _value;
return true;
}
/* A contract attempts to get the coins */
function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
if (_to == 0x0) throw; // Prevent transfer to 0x0 address. Use burn() instead
if (_value <= 0) throw;
if (balanceOf[_from] < _value) throw; // Check if the sender has enough
if (balanceOf[_to] + _value < balanceOf[_to]) throw; // Check for overflows
if (_value > allowance[_from][msg.sender]) throw; // Check allowance
balanceOf[_from] = SafeMath.safeSub(balanceOf[_from], _value); // Subtract from the sender
balanceOf[_to] = SafeMath.safeAdd(balanceOf[_to], _value); // Add the same to the recipient
allowance[_from][msg.sender] = SafeMath.safeSub(allowance[_from][msg.sender], _value);
Transfer(_from, _to, _value);
return true;
}
function burn(uint256 _value) returns (bool success) {
if (balanceOf[msg.sender] < _value) throw; // Check if the sender has enough
if (_value <= 0) throw;
balanceOf[msg.sender] = SafeMath.safeSub(balanceOf[msg.sender], _value); // Subtract from the sender
totalSupply = SafeMath.safeSub(totalSupply,_value); // Updates totalSupply
Burn(msg.sender, _value);
return true;
}
function freeze(uint256 _value) returns (bool success) {
if (balanceOf[msg.sender] < _value) throw; // Check if the sender has enough
if (_value <= 0) throw;
balanceOf[msg.sender] = SafeMath.safeSub(balanceOf[msg.sender], _value); // Subtract from the sender
freezeOf[msg.sender] = SafeMath.safeAdd(freezeOf[msg.sender], _value); // Updates totalSupply
Freeze(msg.sender, _value);
return true;
}
function unfreeze(uint256 _value) returns (bool success) {
if (freezeOf[msg.sender] < _value) throw; // Check if the sender has enough
if (_value <= 0) throw;
freezeOf[msg.sender] = SafeMath.safeSub(freezeOf[msg.sender], _value); // Subtract from the sender
balanceOf[msg.sender] = SafeMath.safeAdd(balanceOf[msg.sender], _value);
Unfreeze(msg.sender, _value);
return true;
}
// transfer balance to owner
function withdrawEther(uint256 amount) {
if(msg.sender != owner)throw;
owner.transfer(amount);
}
// can accept ether
function() payable {
}
}[Solidity] 以太坊合约示例：以太坊支付
由于 Solidity 是基于 EVM，语言层面直接支持以太坊支付。函数添加 paylable 标识，即可接受 ether，并把 ether 存入当前合约，如下合约中的 deposit 函数。
pragma solidity ^0.4.0;
contract supportPay{
// 向当前合约存入以太坊
function deposit() payable{
}
// 查询当前合约的余额
function getBalance() constant returns(uint){
return this.balance;
}
}输出
部署合约之后，分别调用
depoist()和getBalance()
[Solidity] 以太坊合约示例：使用非结构化存储实现可升级合约
Solidity 合约脚本如下，点此下载
pragma solidity ^0.4.24;
/**
* @title Proxy
* @dev Gives the possibility to delegate any call to a foreign implementation.
*/
contract Proxy {
/**
* @dev Tells the address of the implementation where every call will be delegated.
* @return address of the implementation to which it will be delegated
*/
function implementation() public view returns (address);
/**
* @dev Fallback function allowing to perform a delegatecall to the given implementation.
* This function will return whatever the implementation call returns
*/
function () public payable {
address _impl = implementation();
require(_impl != address(0), "address invalid");
assembly {
let ptr := mload(0x40)
calldatacopy(ptr, 0, calldatasize)
let result := delegatecall(gas, _impl, ptr, calldatasize, 0, 0)
let size := returndatasize
returndatacopy(ptr, 0, size)
switch result
case 0 { revert(ptr, size) }
default { return(ptr, size) }
}
}
}
/**
* @title UpgradeabilityProxy
* @dev This contract represents a proxy where the implementation address to which it will delegate can be upgraded
*/
contract UpgradeabilityProxy is Proxy {
/**
* @dev This event will be emitted every time the implementation gets upgraded
* @param implementation representing the address of the upgraded implementation
*/
event Upgraded(address indexed implementation);
// Storage position of the address of the current implementation
bytes32 private constant implementationPosition = keccak256("you are the lucky man.proxy");
/**
* @dev Constructor function
*/
constructor() public {}
/**
* @dev Tells the address of the current implementation
* @return address of the current implementation
*/
function implementation() public view returns (address impl) {
bytes32 position = implementationPosition;
assembly {
impl := sload(position)
}
}
/**
* @dev Sets the address of the current implementation
* @param newImplementation address representing the new implementation to be set
*/
function setImplementation(address newImplementation) internal {
bytes32 position = implementationPosition;
assembly {
sstore(position, newImplementation)
}
}
/**
* @dev Upgrades the implementation address
* @param newImplementation representing the address of the new implementation to be set
*/
function _upgradeTo(address newImplementation) internal {
address currentImplementation = implementation();
require(currentImplementation != newImplementation, "new address is the same");
setImplementation(newImplementation);
emit Upgraded(newImplementation);
}
}
/**
* @title OwnedUpgradeabilityProxy
* @dev This contract combines an upgradeability proxy with basic authorization control functionalities
*/
contract OwnedUpgradeabilityProxy is UpgradeabilityProxy {
/**
* @dev Event to show ownership has been transferred
* @param previousOwner representing the address of the previous owner
* @param newOwner representing the address of the new owner
*/
event ProxyOwnershipTransferred(address previousOwner, address newOwner);
// Storage position of the owner of the contract
bytes32 private constant proxyOwnerPosition = keccak256("you are the lucky man.proxy.owner");
/**
* @dev the constructor sets the original owner of the contract to the sender account.
*/
constructor() public {
setUpgradeabilityOwner(msg.sender);
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyProxyOwner() {
require(msg.sender == proxyOwner(), "owner only");
_;
}
/**
* @dev Tells the address of the owner
* @return the address of the owner
*/
function proxyOwner() public view returns (address owner) {
bytes32 position = proxyOwnerPosition;
assembly {
owner := sload(position)
}
}
/**
* @dev Sets the address of the owner
*/
function setUpgradeabilityOwner(address newProxyOwner) internal {
bytes32 position = proxyOwnerPosition;
assembly {
sstore(position, newProxyOwner)
}
}
/**
* @dev Allows the current owner to transfer control of the contract to a newOwner.
* @param newOwner The address to transfer ownership to.
*/
function transferProxyOwnership(address newOwner) public onlyProxyOwner {
require(newOwner != address(0), "address is invalid");
emit ProxyOwnershipTransferred(proxyOwner(), newOwner);
setUpgradeabilityOwner(newOwner);
}
/**
* @dev Allows the proxy owner to upgrade the current version of the proxy.
* @param implementation representing the address of the new implementation to be set.
*/
function upgradeTo(address implementation) public onlyProxyOwner {
_upgradeTo(implementation);
}
/**
* @dev Allows the proxy owner to upgrade the current version of the proxy and call the new implementation
* to initialize whatever is needed through a low level call.
* @param implementation representing the address of the new implementation to be set.
* @param data represents the msg.data to bet sent in the low level call. This parameter may include the function
* signature of the implementation to be called with the needed payload
*/
function upgradeToAndCall(address implementation, bytes data) public payable onlyProxyOwner {
upgradeTo(implementation);
require(address(this).call.value(msg.value)(data), "data is invalid");
}
}使用方法：
部署
OwnedUpgradeabilityProxy合约，假设合约地址X部署目标合约，假设合约地址
Y调用
OwnedUpgradeabilityProxy合约的接口upgradeTo(Y)生成目标合约指向地址
X，当调用目标合约接口时，实际将数据都存储在OwnedUpgradeabilityProxy合约的地址空间，后续升级目标合约，重新执行步骤 3 即可。
[Julia] Hello World
println("hello world")输出
hello world[Julia] 数学计算
函数形参可以显示指定类型，也可缺省
函数可以有多个返回值
计算圆柱体的体积
计算 aX^2^ + bX + c = 0 一元二次方程的解
# Julia 1.0.0
using Printf
# function to calculate the volume of a sphere
function sphere_vol(r)
# julia allows Unicode names (in UTF-8 encoding)
# so either "pi" or the symbol π can be used
return 4/3*pi*r^3
end
# functions can also be defined more succinctly
quadratic(a, sqr_term, b) = (-b + sqr_term) / 2a
# calculates x for 0 = a*x^2+b*x+c, arguments types can be defined in function definitions
function quadratic2(a::Float64, b::Float64, c::Float64)
# unlike other languages 2a is equivalent to 2*a
# a^2 is used instead of a**2 or pow(a,2)
sqr_term = sqrt(b^2-4a*c)
r1 = quadratic(a, sqr_term, b)
r2 = quadratic(a, -sqr_term, b)
# multiple values can be returned from a function using tuples
# if the return keyword is omitted, the last term is returned
r1, r2
end
vol = sphere_vol(3)
# @printf allows number formatting but does not automatically append the \n to statements, see below
@printf "volume = %0.3f\n" vol
quad1, quad2 = quadratic2(2.0, -2.0, -12.0)
println("result 1: ", quad1)
println("result 2: ", quad2)输出
kevin@kevin-PC MINGW64 /d/go/src/test
$ julia test.jl
volume = 113.097
result 1: 3.0
result 2: -2.0[Julia] 字符、字符串基础用法
包含字符串的大小写、截取、拼接等基础用法，点此下载
# Julia 1.0.0
# 字符、字符串的使用
ch = 'k'
println(ch)
# 转换为数值
println(Int(ch))
str = "THIS a test str"
# 换行、不换行输出
println(str)
print(str)
print(str, "\n")
# 大小写转换
println("uppercase: ", uppercase(str))
println("lowercase: ", lowercase(str))
# 子串
show(str[1:4]); println()
println(str[6:7])
println(str[end-3:end])
# julia 支持字符串插值用法
a = "sb"
b = "jiakong"
println("$a $b")
# 插值用法可以扩展到数学计算
println("2 + 22 = $(2 + 22)")
# 字符串拼接
c = string(a, " ", b)
println(c)
# 可以用 *（非 +）实现字符串拼接
d = a * " + " * b
print(d)输出
$ julia test.jl
k
107
THIS a test str
THIS a test strTHIS a test str
uppercase: THIS A TEST STR
lowercase: this a test str
"THIS"
a
str
sb jiakong
2 + 22 = 24
sb jiakong
sb + jiakong[Julia] 循环、Map
包含循环、Map 的基础用法，点此下载
for i in 1:5
print(i, ", ")
end
#> 1, 2, 3, 4, 5,
# In loop definitions "in" is equivilent to "=" (AFAIK, the two are interchangable in this context)
for i = 1:5
print(i, ", ")
end
println() #> 1, 2, 3, 4, 5,
# arrays can also be looped over directly:
a1 = [1,2,3,4]
for i in a1
print(i, ", ")
end
println() #> 1, 2, 3, 4,
# continue and break work in the same way as python
a2 = collect(1:20)
for i in a2
if i % 2 != 0
continue
end
print(i, ", ")
if i >= 8
break
end
end
println() #> 2, 4, 6, 8,
# if the array is being manipulated during evaluation a while loop shoud be used
# pop removes the last element from an array
while !isempty(a1)
print(pop!(a1), ", ")
end
println() #> 4, 3, 2, 1,
d1 = Dict(1=>"one", 2=>"two", 3=>"three")
# dicts may be looped through using the keys function:
for k in sort(collect(keys(d1)))
print(k, ": ", d1[k], ", ")
end
println() #> 1: one, 2: two, 3: three,
# like python enumerate can be used to get both the index and value in a loop
a3 = ["one", "two", "three"]
for (i, v) in enumerate(a3)
print(i, ": ", v, ", ")
end
println() #> 1: one, 2: two, 3: three,
# (note enumerate starts from 1 since Julia arrays are 1 indexed unlike python)
# map works as you might expect performing the given function on each member of an array or iter
# much like comprehensions
a4 = map((x) -> x^2, [1, 2, 3, 7])
print(a4) #> [1, 4, 9, 49]输出
$ julia test.jl
1, 2, 3, 4, 5, 1, 2, 3, 4, 5,
1, 2, 3, 4,
2, 4, 6, 8,
4, 3, 2, 1,
1: one, 2: two, 3: three,
1: one, 2: two, 3: three,
[1, 4, 9, 49][微信小程序] 利用滑块容器实现内容循环滚动
js 文件给
msgList初始化
/**
* 生命周期函数--监听页面加载
*/
onLoad: function(options) {
var that = this
var user_info = wx.getStorageSync("user_info");
//更新数据
that.setData({
msgList: [
'当前系统版本： v1.0.0',
'当前登录用户：' + user_info.nickname
],
users: [{
"url": "../resource/images/exit.png",
"title": "退出登陆",
"content": "",
"indicator": "../resource/images/next.png"
}]
})
},wxml 文件定义容器
<swiper class="swiper-container" vertical="true" autoplay="true" circular="true" interval="2000">
<block wx:for="{{msgList}}">
<swiper-item>
<view class="swiper-item">{{item}}</view>
</swiper-item>
</block>
</swiper>wxss 文件定义样式
.swiper-container {
width: 100%;
height: 1.2rem;
z-index: 999;
}
.swiper-item {
line-height: 1.0rem;
font-size: 0.8rem;
overflow: hidden;
text-overflow: ellipsis;
white-space: nowrap;
letter-spacing: 0.1rem;
padding-left: 1.0rem;
color: rgb(5, 58, 192);
}[微信小程序] 利用全局属性 globalData 跨页面传值
在
app.js中定义需要跨页面传递的值，例如，向动态配置项目的 URL
App (
globalData: {
URL: 'https://api.bigsillybear.com'
}
// ...
)需要使用值的页面，假设
x.js
// 获取 app 实例
var app = getApp();
// 直接访问 globalData 即可
console.log('URL: ', app.globalData.URL)[微信小程序] 解决 switchTab 不刷新
当 switchTab 点击过的时候，只有第一次加载数据，第二次点击的时候不刷新数据。将需要重新加载的逻辑抽取出来，在 onShow() 中调用即可，当然，也可以直接将此逻辑放在 onShow() 中。
onShow:function(e){
this.dummy();
}[微信小程序] 获取屏幕宽高
利用微信小程序接口
onLoad: function () {
this.setData({
height: wx.getSystemInfoSync().windowHeight,
width: wx.getSystemInfoSync().windowWidth
})
}利用 css3 特性
.body {
height: 100vh; /*view height*/
width: 100vw; /*view width*/
background-color: greenyellow;
}[微信小程序] 模态对话框换行
wx.showModal({
title: '提示',
content: '前置条件:用户当前余额为零\r\n\r\n确定要删除[' + e.target.dataset.phone + ']吗?',
success: function(sm) {
}
})使用 \r 即可实现换行。目前，在微信开发者工具上显示不换行，但是真实环境可换行。
[微信小程序] 长按复制
/**
* 长按复制
*/
copy: function(e) {
var that = this;
// console.log(e.target.dataset.phone);
wx.setClipboardData({
data: e.target.dataset.phone,
success: function(res) {
wx.showToast({
title: '复制成功',
duration: 1000
});
}
});
}需要添加长按复制功能的元素绑定该函数即可
<text bindlongpress='copy' data-phone='{{phone}}'>{{phone}}</text>[微信小程序] 分页加载
分页加载是常见的优化技巧，也是提升用户体验的一方面。既减轻服务端的业务压力，又提升了用户体验。一般地，需要前后端配合实现。
前端动态加载（通过多次拉取数据，更新）
后端接口支持分页查询
<view class="table">
<view class="noResult" hidden="{{!noResult}}">对不起，您查询的结果为空！</view>
<view wx:if="{{list.length > 0}}">
<view class="th">
<view class='td-title' style='width:30%'>手机号码</view>
<view class='td-title' style='width:15%'>用户名</view>
<view class='td-title' style='width:15%'>余额</view>
<view class='td-title' style='width:40%'>操作</view>
</view>
<view class="tr bg-g" />
<scroll-view scroll-y="true">
<view>
<block wx:for="{{list}}" wx:key="{{phone}}">
<view class="tr bg-g" wx:if="{{index % 2 == 0}}">
<view class='td-content' style='width:30%'>
<text bindlongpress='copy' data-phone='{{item.phone}}'>{{item.phone}}</text>
</view>
<view class='td-content' style='width:15%'>{{item.nickname}}</view>
<view class='td-content' style='width:15%'>{{item.balance}}</view>
<view class='td-content' style='width:40%'>
<view>
<navigator class='link' url='../userdetail/userdetail?phone={{item.phone}}'>用户详情</navigator>|
<navigator class='link' url='../operation/operation?phone={{item.phone}}&nickname={{item.nickname}}'>用户编辑</navigator>
</view>
<view>
<text class='link' bindtap='deleteUser' data-phone='{{item.phone}}' data-index='{{index}}'>用户删除</text>|
<text class='link' bindtap='consumeManager' data-phone='{{item.phone}}' data-index='{{index}}'>消费管理</text>
</view>
</view>
</view>
<view class="tr bg-w" wx:else>
<view class='td-content' style='width:30%'>
<text bindlongpress='copy' data-phone='{{item.phone}}'>{{item.phone}}</text>
</view>
<view class='td-content' style='width:15%'>{{item.nickname}}</view>
<view class='td-content' style='width:15%'>{{item.balance}}</view>
<view class='td-content' style='width:40%'>
<view>
<navigator class='link' url='../userdetail/userdetail?phone={{item.phone}}'>用户详情</navigator>|
<navigator class='link' url='../operation/operation?phone={{item.phone}}&nickname={{item.nickname}}'>用户编辑</navigator>
</view>
<view>
<text class='link' bindtap='deleteUser' data-phone='{{item.phone}}' data-index='{{index}}'>用户删除</text>|
<text class='link' bindtap='consumeManager' data-phone='{{item.phone}}' data-index='{{index}}'>消费管理</text>
</view>
</view>
</view>
</block>
</view>
<view class="tr" hidden="{{!listLoading}}" bindtap="listMore">点击加载更多...</view>
<view class="tr" hidden="{{!listLoadingComplete}}">已加载全部</view>
</scroll-view>
</view>
</view>长按绑定 listMore，长按触发从后台重新拉取数据，然后更新 list: that.data.list.concat(list)
fetchList: function() {
var that = this;
wx.request({
url: app.globalData.URL + '/usermanage/user/list',
data: {
"id": that.data.id,
"count": gCount
},
method: 'POST',
success: function(res) {
if (res.data.errorcode == 0) {
var list = res.data.data;
var length = list.length;
that.setData({
listLoading: length != gCount ? false : true,
listLoadingComplete: length != gCount ? true : false,
id: list[length - 1].id,
list: that.data.list.concat(list),
});
} else {
that.setData({
listLoading: false,
listLoadingComplete: true,
noResult: that.data.list.length == 0 ? true : false
});
}
}
})
},
//点击加载更多
listMore: function() {
let that = this;
console.log(that.data.listLoading, that.data.listLoadingComplete);
if (that.data.listLoading && !that.data.listLoadingComplete) {
that.fetchList();
}
},后台接口 /usermanage/user/list 包含两个参数，一个起始 ID，一个指定一次性拉取记录条数。
[js] 判断字符串为空
//判断字符是否为空的方法
function isEmpty(obj){
if(typeof obj == "undefined" || obj == null || obj == ""){
return true;
}else{
return false;
}
}使用方式如下
if (!isEmpty(value)) {
alert(value);
}[js] 以太坊导出私钥
通过
npm install keythereum安装依赖库
var keythereum = require("keythereum");
var datadir = "./testnet";
var address= "0x96d81d81149a3a8501eb99fb8aca1cff5cc19d7c";
const password = "123";
var keyObject = keythereum.importFromFile(address, datadir);
var privateKey = keythereum.recover(password, keyObject);
console.log(privateKey.toString('hex'));Last updated