C# how to make it efficient to list the directories on a ftp server -

i need content of file list files specific format ftp server. have read through directories , files, check if or contains file need, add file file list. however, there many directories, subdirectories, , kinds of files in ftp server, time-consuming that. know how can make more time efficient?

since have mentioned directory path varies machine machine, need have collection of machines , there directory paths. need loop through directory paths. unfortunately need loop through every files (exclude unwanted). below pseudocode-

loop each directory paths     loop each files in directory paths excluding unwanted files types          store required files in collection     end loop end loop return files 

you may use parallel loop (tpl in .net) execute loops faster. refer-

• https://msdn.microsoft.com/en-us/library/dd460713(v=vs.110).aspx
• https://msdn.microsoft.com/en-us/library/dd537609(v=vs.110).aspx