GeoTIFF metadata / ftp download

gistfile1.txt

"""
This likely isn't useful to anybody else.  But it's an example of how to
adapt python's ftplib to grab just the first few kb of a given file.

In this case, all we need is the first few kb to get the metadata from a
GeoTIFF file.
"""

import ftplib


MAX_FILE_SIZE = 8192 * 12

file_list = []
cur_file = None
cur_filename = None
cur_file_size = 0


class FTP(ftplib.FTP):
    def retrbinary(self, cmd, callback, blocksize=8192, rest=None):
        global cur_file_size
        self.voidcmd('TYPE I')
        conn = self.transfercmd(cmd, rest)
        while 1:
            data = conn.recv(blocksize)
            if not data:
                break
            callback(data)

            cur_file_size += blocksize
            if cur_file_size > MAX_FILE_SIZE:
                cur_file_size = 0
                break
        conn.close()
        self.abort()
        return self.voidresp()


def process_line(line):
    file_list.append(line.split()[-1])


def handleDownload(block):
    global cur_file, cur_file_size, cur_filename

    if cur_file is None:
        cur_file = open(cur_filename, 'w')

    cur_file.write(block)


def download(dirnum):
    global cur_filename, cur_file
    ftp = FTP('n4ftl01u.ecs.nasa.gov')
    ftp.login()
    ftp.cwd('SAN2/ICEBRIDGE_FTP/IODMS1B_DMSgeotiff_v01/2009_AN_NASA/Flt_%s' % dirnum)

    ftp.retrlines('LIST', process_line)

    for filename in file_list:
        cur_filename = filename
        try:
            ftp.retrbinary('RETR ' + filename, handleDownload)
            cur_file.close()
            cur_file = None
            print "Got metadata for", filename
        except Exception, s:
            print str(s)
            continue


for x in xrange(1000109, 1000130):
    download(x)

download(1000133)