Perform FTP File Operations

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This example shows how to use an FTP object to connect to an FTP server and perform remote file operations. To perform any file operation on an FTP server, follow these steps:

  1. Connect to the server using the ftp function.

  2. Perform operations using the appropriate MATLAB® FTP functions, such as the cd, dir, and mget functions. Specify the FTP object for all operations.

  3. When you finish work on the server, close the connection using the close function.

The National Centers for Environmental Information (NCEI) maintain an anonymous FTP service providing public access to geophysical data. Access the FTP server to list its contents, download a file, and list contents of a subfolder.

First, open the connection.

ftpobj = ftp('ftp.ngdc.noaa.gov')
  FTP with properties:

                         Host: "ftp.ngdc.noaa.gov"
                     Username: "anonymous"
                         Port: 21
                 ServerLocale: "en_US"
                 DirParserFcn: @matlab.io.ftp.parseDirListingForUnix
                         Mode: "binary"
    LocalDataConnectionMethod: "passive"
       RemoteWorkingDirectory: "/"
          CertificateFilename: "default"
            ConnectionTimeout: 5 min
              TransferTimeout: Inf sec

List the contents of the top-level folder on the FTP server.

dir(ftpobj)
 
DMSP                         INDEX.txt                    README.txt                   STP                          Snow_Ice                     Solid_Earth                  coastwatch                   dmsp4alan                    ftp.html                     geomag                       google12c4c939d7b90761.html  index.html                   international                ionosonde                    mgg                          pub                          wdc

Download the file named INDEX.txt using the mget function. mget copies the file to the current MATLAB folder on your local machine. To view the contents of your copy of the file, use the type function.

mget(ftpobj,'INDEX.txt');
type INDEX.txt
                    National Centers for Environmental Information (NCEI), 
                    formerly the National Geophysical Data Center (NGDC)

                          INDEX of anonymous ftp area
                               ftp.ngdc.noaa.gov

DIRECTORY/FILE DESCRIPTION OF CONTENTS
-------------- -----------------------------------------------------------------
pub/           Public access area 
DMSP/          Defense Meteorological Satellite Data Archive
geomag/        Geomagnetism and geomagnetics models
hazards/       Natural Hazards data, volcanoes, tsunamis, earthquakes
international/ International program information on IAGA/Oersted/wdc
ionosonde/     Ionosonde data
mgg/           Limited Marine Geology and Geophysics (most data in http area)
OD/            Office of the Director
Snow_Ice/      Snow and Ice Data Center
Solid_Earth/   Historic Solid Earth Geophysics
STP/           Solar-Terrestrial Physics
tmp/           Pickup area for temporary outgoing data
wdc/           World Data Service for Geophysics, formerly World Data Centers
-------------- -----------------------------------------------------------------
Please see file README.txt in this directory for more information and how to 
contact NCEI. Direct E-mail inquiries to ncei.info@noaa.gov

Also see our web site: http://www.ngdc.noaa.gov/

NCEI is part of the:
U.S. Department of Commerce, National Oceanic and Atmospheric Administration (NOAA),
National Environmental Satellite, Data and Information Service (NESDIS)

Change to the subfolder named pub on the FTP server.

cd(ftpobj,'pub')
ans = 
'/pub'

List the contents. pub is now the current folder on the FTP server. However, note that the current MATLAB folder on your local machine has not changed. When you specify an FTP object using functions such as cd and dir, the operations take place on the FTP server, not your local machine.

dir(ftpobj)
 
WebCD     coast     glac_lib  krm       outgoing  results   rgon

Close the connection to the FTP server.

close(ftpobj)

FTP service courtesy of the NCEI. See the NCEI Privacy Policy, Disclaimer, and Copyright for NCEI terms of service.

See Also

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