Avoiding certain hosts for any sort of work

Do not use student.cs for any sort of development or testing. Invoke hostselect +listup undergrad to get a list of all available hosts for you to work and play with. The subset of those servers listed by hostselect attr=cpu +listall are what you should use exclusively for testing or other CPU-intensive work.

CSCF maintains a web page describing the hosts available in the student computing environment at http://www.cs.uwaterloo.ca/cscf/student/hosts. For example, cpu-solaris.student.cs will select a Solaris server for CPU-intensive work while fe-linux.student.cs will select a Linux server for general interactive use.

pkill and pgrep

pkill kills all processes with a given name. For instance pkill java kills all java processes

pgrep lists all the pids of processes matching a given name. For insance pgrep java lists all the pids of java processes.

There was once an issue where a parent process created the child process repeatedly without killing anything. The cause was unknown and the command pgrep _ | xargs kill killed everything connected to it at once.

getBoxNumber

Returns the box number for a given student. For instance, /u/isg/pub/bin/getBoxNumber djshaw will return 30, djshaw's box number.

UNIX 101

Unfamiliar with the UNIX command-line interface? Have a look at (among other things) the Computer Science Club's excellent UNIX 101 Tutorial. (KyleSpaans taught this a couple of times)

At and deadline

Sometimes this does not work; make sure you manually close and check it for each deadline -n.

NB: The at command should always work. If it does not, testing needs to be done so the cause can be discovered, your ISC should be notified with the details of what causes the failure, and the cause of the error can then hopefully be fixed.

Removing temporary files recursively.

The find command can help with this. For example, to get rid of all files rooted in your home directory ending in ~ or #, you can create the following csh alias:

alias cleanup "find $HOME -name '*[~#]' -exec rm {} \;"

and then just type cleanup in any directory when you want to nuke all such files.