Transferring files between Remote and Math/CS Linux System


You can transfer files between your machine and the Math/CS Linux lab machines.  This is especially useful if you are running Linux software remotely: you can edit files on your machine, transfer the file to the Linux system, run the Linux software, and possibly transfer results back to your system for further processing or editing.

To perform such transfers, you need to first download some free software that will allow you to connect securely to the Math/CS lab servers.  (A secure connection means that the information passed between your computer and the Math/CS computers is encrypted.)  I suggest using a program called "psftp", which is available at http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html.  (If you are running Windows, the specific file you want is http://the.earth.li/~sgtatham/putty/latest/x86/psftp.exe).  Simply download this file to your desktop.

Once you have psftp, double-click the psftp.exe shortcut to start the program.  In the window that appears, you will see the message

psftp: no hostname specified; use "open host.name" to connect
psftp>

Following the prompt (psftp>), enter

open server3.mathcs.duq.edu

and press enter.  After a brief pause, you should see a login prompt.  Enter your Math/CS user name (the one you use to log in to Math/CS lab computers) and press Enter.  When prompted for your password, enter your Math/CS password.

Before transferring files, you need to be in the appropriate folder (directory) on both your machine and on the Math/CS server machine.  You are initially in your Desktop folder on your machine and in your home directory on the Linux machine.  You use the cd command to change directories on the Linux side, just as you would if you were using a shell window.  You use a command named lcd (local change directory) to change directories on the Windows side.  The lcd command is exactly like the cd command except for its name and except for which machine the change happens on.

For example, to move into your public_html directory in Linux and into a folder called CS within a folder called papers that is on your Desktop, you would enter the commands

cd public_html
lcd papers/CS

Notice that the forward slash / is always used to separate folders in psftp, regardless of whether the system on which the folders reside is Linux or Windows.

Once you're in the right directories, you move a file from your machine to the Linux server by using the put command and from Linux to your machine by using the get command.  For example, if we wanted to move a file named status_report.tex from our machine to the Linux system, we would enter

put status_report.tex

Important note: if you want to transfer a non-text file (such as an image) rather than a text file, then you must issue the command

bin

(short for binary) before performing the transfer.  To switch back to the default text mode, issue the command

asc

(short for ASCII).

When you're done using psftp, enter bye.