LibCurl是免费的客户端URL传输库，支持FTP,FTPS ... Libcurl具备线程安全、IpV6兼容、易于使用的特点,支持多种平台-libcurl is a free and easy-to-use client-side URL transfer library, supporting FTP, FTPS, HTTP, HTTPS, SCP, SFTP, TFTP, TELNET, DICT, LDAP, LDAPS and FILE. libcurl supports SSL c