CS 380: Working from home

Regardless of where you work, it is assumed that you have some facility working at a command line. If you don’t you may want to check out The Linux Command Line: A Complete Introduction, available online from libraries in all three campuses.

This course is designed around the software that is available in the CS labs. (CS labs at both campuses have the requisite software.) You may have the best experience working at the lab computers. However, if that is not feasible, it is very possible to work from home. This page has some instructions on how to do this effectively.

From a Mac, working locally

Mac OS X is actually a variant of UNIX, just like Linux is a variant of UNIX. This means that you will be able to complete your assignments on your computer quite nicely. To get to the command line, just launch the Terminal app (in the Utilities folder under Applications, or available via Spotlight).

You will need the Haskell Platform Minimal, available here (click the button labeled “Core”). After installing this, you should be able to run GHC from the Terminal. Try typing ghci.

You will also likely want some Haskell gubbins for your editor. Various editors have various levels of Haskell integration; emacs and Atom seem to have the best. Searching online for how to set these up with Haskell works nicely.

From a Mac, working remotely

If you don’t want to worry about setting software up on your own machine, you are welcome to connect to Bryn Mawr’s CS server, powerpuff. Just open Terminal and say ssh@powerpuff.cs.brynmawr.edu. You will then have command-line access to the CS server, from where you can run emacs and start programming.

When you need to copy files back and forth between your machine and the server, you can use scp.

An alternative approach here is to sshfs, which allows you to access your networked home directory as if it were local. First, install FUSE for MacOS, and then install sshfs (available on that same page). Once installed, you can mount your networked home directory locally:

Create an empty directory anywhere. To be concrete, I’ll make one called cs in my home directory with
```
cd
mkdir cs
```
Then just say sshfs -o auto_cache <your cs username>@powerpuff.cs.brynmawr.edu: <your empty directory>. Continuing my example, I would type
```
sshfs -o auto_cache rae@powerpuff.cs.brynmawr.edu: cs
```
Note the : at the end of the address! Then, you should see your networked home directory in cs. Any file you write in the cs directory also gets copied to the server. This way, you can edit locally (with emacs or Atom on your own computer) but still compile on powerpuff via ssh.

If you want to disconnect, just say umount <your empty directory>. In my case, that’s umount cs.

See also the last section here about some advice about working remotely.

From Windows, working locally

Windows does not have nearly the power of a Mac when it comes to programming. It is possible to get everything working on Windows, but it’s not easy. Given the wide range of situations out there, all I can do here is recommend a few starting points – it will be up to you to get all the software working, I’m afraid.

You should install MinGW and MSYS (or you could use the heavier-weight Cygwin) to get a working command line. Then, install the Haskell Platform Minimal (a.k.a. Core). You should now be able to run ghci from the command line.

From Windows, working remotely

Windows also does not come with a built-in ssh (Secure SHell) client. Download PuTTY, both the putty.exe and pscp.exe files. Launching putty.exe, you will be able to configure a connection to powerpuff.cs.brynmawr.edu, using your CS username. It is worthwhile looking through the other settings available, as tweaking them may prove fruitful. The pscp.exe program will allow you to copy files back and forth between your computer and the server.

Once you have logged in with PuTTY, you should be able to run emacs or ghci, and away you go.

An alternative approach is to use SSHFS, which allows you to access your networked home directory as if it were local. This guide is up-to-date and seems reasonable, but I have not tested it myself. The Host should be powerpuff.cs.brynmawr.edu; other settings should be straightforward. If you try this and have thoughts you wish to share, edit this page and submit a pull request.

See also below for some advice about working remotely.

Helpful commands when working remotely

When working via ssh or PuTTY, you do not have direct access to the files you are working with. (For example, you can’t just save files from web pages into the server.) While you can always use scp or pscp.exe, this is often inconvenient. Below are some tips for common scenarios:

Use multiple windows! It is always possible to have multiple ssh or PuTTY sessions at the same time. This is much easier than exiting emacs every time you wish to compile!
If you need to download a file from the web, from URL http://example.com/file.txt, use wget http://example.com/file.txt.
Some terminals have a hard time with emacs’s M- key. So any M-blah command in emacs can also be executed by typing ESC blah. So, instead of M-x, you would type ESC x. Note that ESC and x are not typed at the same time here.
Check out the emacs reference card.

Have a tip to add? Create a pull request!