Utility Programs for Linux
Listed below are a few utility programs developed by CAEN for the Linux computing environment.
hostinfo
In addition to the HostInfo web page, the hostinfo command can be used to list lab machines currently available. With no options, hostinfo lists the ten least-used machines along with status and system information. You can also set hostinfo to look for specific types of machines based on operating system, location, etc. For example, to get a list of available Linux computers to connect to, type hostinfo -linux. For more information, type hostinfo -help at the Linux prompt.
redot
Every CAEN Linux user has a set of customization files, also called dotfiles, with which one can personalize their Linux environment. The /usr/caen/bin/redot script copies over new (default) dotfiles, and makes sure that Public and Private directories exist and have the correct permissions. This utility can be used if your current dotfiles are corrupted or deleted, preventing you from logging into the console of Linux machines. The script moves all existing dotfiles to filename.old (for example .login moves to .login.old, and is replaced with the default file).
rmproc
You can use the rmproc command to remove remote user processes from running on a Linux workstation when you are logged on at the console. The rmproc utility program applies heuristics in determining which processes to kill. Depending on the characteristics of a given process, rmproc will provide advice as to whether or not it is worth killing. Rmproc excludes system processes from consideration and will not list them or provide the option of killing them. Small jobs, defined for lab machines to be those that have used less than 10 minutes of CPU time, those that are suspended, and those that use less than 10 MB of memory will also be excluded.
For in-depth documentation about the rmproc command, refer to the online manual page by typing man rmproc
setup_k5login
The setup_k5login utility (located at /usr/um/bin/setup_k5login) enables non-password, Kerberos login over SSH from one CAEN Linux host to another. For example, after running this utility once, users may connect to the login servers from off-campus and then connect to any lab host from without entering their password. Running this command is required to use Kerberos remote login from a Windows machine to Linux, and is also required for individuals whose home directories are located in the umich.edu AFS cell.
swselect
Software Select (swselect) is used to organize which software packages, and versions of those software packages, your Linux account is configured to use by default. It can be run remotely via terminal text menus, or locally with a graphical menu. To run swselect, type swselect at any Linux prompt. Any changes that you make in your software listing will take effect immediately after you type source ~/.software. This will also be done automatically every time you log in, after running the program.
xloginsession
X11 software enables connections to the login servers using SSH tunnelling, and allow users to run Linux software remotely. For instance, Exceed for Windows and the X11 application for Mac OS can be used to forward X11 connections over SSH. By default, however, these methods will not let users fully simulate an entire Linux desktop environment. The xloginsession script (located at /usr/um/bin/xloginsession) will start a GUI login session anytime you connect to a CAEN Linux host (e.g. login.engin.umich.edu) using X11 forwarding over SSH. xloginsession will execute your default Linux desktop environment along with the default language that you've previously selected on a CAEN lab computer. Once connected over X11, simply type the following in your SSH window to start a session: xloginsession
