Department of Engineering

IT Services

Getting files in and out of the Teaching System

There are many ways to get files in and out of the Teaching System. The range of methods changes (sometimes at short notice) because of security considerations. The method you use depends on the size and number of files to be copied, where the other machine is (some methods only work inside CUED), and who else will have access to the files.

If you're regularly accessing Teaching System files from another CUED machine you might wish to set up a more permanent arrangement where your Teaching System files appear as a folder on your screen. See our Accessing your home directory from a Windows PC page.

Copying files

  • Mail - you can post a file as an attachment from one machine and download it onto another. There are size restrictions on mail items. Also, the attached files are usually encoded, so you need to ensure that the mail program at the other end can cope with the encoded file.
  • scp - "secure copy" is a program that copies files using the same kind of security as "slogin" and "ssh" use. It's available from the command line on some machines. On others it may be incorporated into a friendly interface. Single files or folders of files can be copied. If you want to use it to access the Teaching System from afar you're currently restricted using gate. For example, if user abc1 was on a Mac in Australia and wanted to copy their work folder and everything under it from their home folder on CUED's Unix Teaching System, they could do
    scp -r abc1@gate.eng.cam.ac.uk:work .
    (the final dot matters!). See our ssh page for further details.
  • WWW - anyone at CUED can put files on the WWW by putting them in their ~/public_html folder. Once the files are made readable by all, anyone with a browser can download them onto their own machine. The only size restriction is that imposed by the usual disc-quota limits. See the Getting your files onto the WWW page for details.
  • sftp - sftp is a replacement for the older, less secure ftp.
  • ftppub - if you want to temporarily "publish" files so that anyone in the world can use ftp to copy them, read about ftppub. For more permanent arrangements, or group-based activities, see the ftp page.
  • ftpupload - if you want to let anyone use ftp to send files to you, read about ftpupload
  • memory stick, flash memory, flash drive - you can use the DPO machines

Compressing files

Big files might benefit from being compressed before transfer. You need to ensure that you can uncompress the file after transfer. Nowadays, programs that compress can usually bundle files up too. The most portable compression program on the Unix Teaching System is zip (versions are available for MacOS, Windows, etc). On the Unix Teaching System typing 

    zip small big

will create a file called "small.zip" which will be a compressed version of the existing "big" file. Type "man zip" for details.

Bundling files up

Sometimes it helps to bundle a collection of files into a single file before transfer. You need to ensure that you can "undo" the bundle after the tranfer. The most portable "bundling" program on the Unix Teaching System is zip, which will also compress the bundle. For example, if on the Unix Teaching System you have files called "one" and "two" in the current directory, then typing 

    zip bundle one two

will create a file called "bundle.zip" which can be copied elsewhere and unbundled using 

    unzip bundle

(or you can use many of the common decompression programs on MacOS/Windows machines). Type "man zip" for details.

See Also