FileSupport
functions for traverse subfolders and subfiles, counting how many lines are there in a file
###Functions
typedef std::string String;
typedef std::vector<String> FileList;
typedef std::vector<String> FolderList;
/**
* @brief { list sub level of folder under the path }
*
* @param[in] path { folder path }
*
* @return { vector of subfolders }
*/
FolderList list_folders(String path);
/**
* @brief { list files under the path }
*
* @param[in] path { folder path }
*
* @return { vector of subfiles }
*/
FileList list_files(String path);
/**
* @brief { list all files under the path recurrently }
*
* @param[in] path { folder path }
* @param files { vector of all subfiles }
*/
void list_files_recurrently(String path, FileList &files);
/**
* @brief { count the lines of a file }
*
* @param[in] filename { path of file }
*
* @return { how many lines }
*/
int get_file_line_num(String filename);