Thursday, March 31, 2016

Software Management with YUM

YUM (Yellowdog Updater, Modified) is the package management tool used on Red Hat Enterprise Linux and its derived versions, CentOS and Scientific Linux. It acts as a front end to the RPM Package Manager (RPM), and is used to install, remove, and update software on Red Hat based systems.

I first encountered YUM when installing Yellow Dog Linux on PowerPC based Macintosh computers back at the dawn of the 21st century.  When I switched over to Debian based GNU/Linux systems with the release of Ubuntu in 2004, I completely lost touch with the RPM world until my Spring semester Linux System Administration course's pursuit of RHCSA certification brought me back into the fold.

I am writing this post to use as a handy list of the most common things I need to do when managing software:
  1. Update the software on the system
    $ yum check-update
    $ sudo yum update package_name
    $ sudo yum update [to update all packages]
    $ sudo yum group update group_name
  2. List all the currently installed software
    $ yum list installed
    $ yum list installed "global expression"
  3. Search for available packages
    $ yum list available "global expression"
    $ yum search term...
  4. Display information about a package
    $ yum info package_name
  5. Install a new package
    $ sudo yum install package_name
  6. Remove an existing package
    $ sudo yum remove package_name
  7. List the current repos
    $ yum repolist
    $ yum repolist -v
That covers the basics. I also need to learn how to clean up the cruft that accumulates over time as a system is run, in Debian land the kind of thing that would be done with $ sudo apt-get autoremove. It seems that in RPM space that is accomplished with the package-cleanup utility, so I'll look into that.


Saturday, March 19, 2016

Centos Command-line Tricks and Tips - Getting Rid of the Terminal Beep

Getting Rid of the Terminal Beep:

My terminal was making an annoying beeping (more like a swoosh beep, actually) every time it couldn't match a tab completion.  I like to listen to music while I work, so this was really driving me crazy.  All I needed to do to stop it was to run:
$ echo 'set bell-style none' >> ~/.inputrc
which appends 'set bell-style none' to the .inputrc file in my home directory.  .inputrc didn't exist in my home directory (I checked before running the command), so running this command created it.
After exiting the terminal and starting another, the terminal maintained the silence I wanted it to ;-)