Questions we often are asked:
- How should I request course based file services?
- I need a commercial software package, how do I request it?
- How can I change members of my research group?
- Recently I have been forced to use https, why?
- How can I change my shell?
- Is there a tool to test my regular expressions (REGEX)?
- Something is wrong with Colby IT, what’s broken?
- Can I do anything to protect my privacy on the internet?
- How can I access Safari Online for computer/IT texts?
- How many processors are available on this linux host (or node)?
- How can I display graphics from a Unix host (X over ssh) to a windows machines?
- XQuartz seems to be blocking OpenGL applications over ssh on Macintosh OS.
- When I ssh to a server, says the ssh keys have changed, what do I do?
- Is there a quick boot camp for using the Unix Shell?
For a course use http://www.colby.edu/acits/fileserverfolder/
Use the online request form: http://www.colby.edu/its/software/sw-request-form/
This is going to happen on more and more domains through the use of HSTS (more info).
I entered http://cs.colby.edu and it was switched by the browser to use https://cs.colby.edu I don’t want this to happen, what can I do? One solution is https://andystechlife.wordpress.com/2016/09/18/how-to-clear-hsts-settings-in-chrome-and-firefox/.
On a Unix host a standard user can change their shell with the command chsh
Will show you the options for using the command and you can find out what shells can be used by
typing cat /etc/shells
Here is the typical output of that:
Yes, there is a wonderful online resource: https://regexr.com/
The best 10,000 ft (think what would Doug, Cindy or David need to know) is https://its-status.colby.edu/.
If you want, you can sign up for text alerts if something changes there.
Yes! For starters switch to duckduckgo for all web searches.
Consider using Do Not Track in your browser preferences.
Only accept cookies for the current session and from reputable sites,
never from third parties.
Get a view of who is tracking you by installing a visualization tool like lightbeam.
How many processors are available on this linux host (or node)?
The simplest way is to type ‘nproc’. This will return the number of processors on the local machine, if hyperthreading is turned on, it will report twice the number of physical processors. Much more information about the processors can be found by inspecting the file /proc/cpuinfo. It might be best to use ‘less /proc/cpuinfo’ to look around and gain deeper understanding.
How can I display graphics from a Unix host (X over ssh) to a windows machines?
There are a few ways to solve this, but the best we know of is documented here http://www.geo.mtu.edu/geoschem/docs/putty_install.html and combines xming with putty.
XQuartz seems to be blocking OpenGL applications over ssh on Macintosh OS. This appears to be a security setting to prevent indirect rendering in XQuartz. On the host you might see an error such as “XRequest.149: BadValue (integer parameter out of range for operation) 0x0 ERROR) Could not create OpenGL rendering context-> Exiting…”
You can disable this setting on a per user basis by (first shutting down Xquartz) opening a terminal and entering:
defaults write org.macosforge.xquartz.X11 enable_iglx -bool true
On rare occasions I have to update server based host keys. You will need to remove the old one in order to make a ssh connection.
The ssh key is stored in your home directory, within the .ssh directory, in a file named known_hosts. Either delete the file (‘rm ~/.ssh/known_hosts’) or remove the offending line with your favorite text editor (‘vi ~/.ssh/known_hosts’).