使用Boost Asio库从NCBI高速下载FASTQ文件 - C++示例

{"title": "使用Boost Asio库从NCBI高速下载FASTQ文件 - C++示例", "description": "本文提供了一个使用C++ Boost Asio库从NCBI高速下载FASTQ文件的示例代码。该代码使用指定的accession号作为参数，连接到NCBI服务器，发送下载请求，并接收数据写入本地文件。", "keywords": "C++, Boost Asio, NCBI, FASTQ, 下载, accession号, 文件", "content": "#include "iostream"\n#include "fstream"\n#include "boost/asio.hpp"\n\nusing boost::asio::ip::tcp;\n\nvoid download_fastq(const std::string& accession) {\n boost::asio::io_context io_context;\n tcp::resolver resolver(io_context);\n tcp::socket socket(io_context);\n\n // 解析NCBI服务器的地址和端口\n tcp::resolver::results_type endpoints = resolver.resolve("ftp.ncbi.nlm.nih.gov", "ftp");\n \n // 连接到NCBI服务器\n boost::asio::connect(socket, endpoints);\n\n // 发送下载请求\n std::string request = "RETR /sra/sra-instant/reads/ByRun/sra/" + accession.substr(0, 3) + "/" + accession + "/" + accession + ".fastq.gz\r\n";\n socket.send(boost::asio::buffer(request));\n\n // 创建本地文件\n std::ofstream outfile(accession + ".fastq.gz", std::ios::binary);\n\n // 接收并写入数据\n std::array<char, 8192> buffer;\n boost::system::error_code error;\n while (socket.read_some(boost::asio::buffer(buffer), error)) {\n outfile.write(buffer.data(), buffer.size());\n }\n\n // 关闭socket和文件\n socket.close();\n outfile.close();\n\n if (error != boost::asio::error::eof) {\n throw boost::system::system_error(error);\n }\n}\n\nint main() {\n std::string accession = "SRR000001"; // 输入你想要下载的accession号码\n try {\n download_fastq(accession);\n std::cout << "FASTQ文件下载完成" << std::endl;\n } catch (std::exception& e) {\n std::cerr << "下载失败: " << e.what() << std::endl;\n }\n\n return 0;\n}\n"}