CODEWITHSUNDEEP
pythonmultithreadingsocketsftp
hammus
hammus

Reputation: 2612

python ftplib transfercmd() BINARY Mode

in the absence of an answer to my previous question.

I am using multihtreading to keep a large FTP transfer alive via the control socket.

Unfortuantely this requires the use of ftplib.ftp.transfercmd() (rather than FTP.retrbinary() which does not give explicit socket control) which returns the data socket exclusively and allows you to send 'NOOP' commands without blocking.

This is a problem as transfercmd("RETR" ...) defaults to dwonloading in ASCII mode which corrupts the video files I'm trying to download.

I have scoured everything Ican to find an explicit BINARY mode command to no avail. Any ideas?

heres is my download code

def downloadFile(filename, folder):
    #login
    ftp = FTP(myhost,myuser,passw)
    ftp.set_debuglevel(2)
    sock = ftp.transfercmd('RETR ' + filename)
    def background():
        f = open(folder + filename, 'wb')
        while True:
            block = sock.recv(1024*1024)
            if not block:
                break
            f.write(block)
        sock.close()
    t = threading.Thread(target=background)
    t.start()
    while t.is_alive():
        t.join(60)
        ftp.voidcmd('NOOP')

Upvotes: 2

Views: 6942

Answers (1)

ThinkChaos
ThinkChaos

Reputation: 1853

As retrbinary()'s source suggests you have to tell the FTP server you want binary with the TYPE I command:

ftp.voidcmd('TYPE I')
# Do the transfer here

retrbinary actually does the transfer for you, but doesn't seem to update the connection to keep it from closing.

Also you don't need a thread, just put ftp.voidcmd('NOOP') in the download loop:

def downloadFile(filename, folder):
    #login
    ftp = FTP(myhost,myuser,passw)
    ftp.set_debuglevel(2)
    ftp.voidcmd('TYPE I')
    sock = ftp.transfercmd('RETR ' + filename)
    f = open(folder + filename, 'wb')
    while True:
        block = sock.recv(1024*1024)
        if not block:
            break
        ftp.voidcmd('NOOP')
        f.write(block)
    sock.close()

Upvotes: 5

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