Best of Tech
These instructions for setting up Cox cable, which reader Matt Reynolds asked about in the September 2002 issue, are good for Tucson, Arizona, and most likely, for all Cox accounts. Cox uses DHCP and issues everybody what they call a CX number, which is needed to obtain an IP address from their servers. To make the DHCP client obtain an IP address, simply include that CX number in the dhcpcd command with the -I (client identifier) option:
/sbin/dhcpcd -I <cx number> <interface, (default eth0)>
It would be a shame if Matt canceled his Cox account because he couldn't get Linux to obtain an IP address, as Cox in Arizona is excellent.
—Patrick Kellaher, email@example.com
I am trying to install KDE 3.0.3 on a fresh system, where neither KDE nor GNOME was installed, using RPMs. When I try to install qt-3.0.5-16.i386.rpm, I get:
[root@yeller rpms]# rpm -Uvh qt-3.0.5-16.i386.rpm error: failed dependencies: libcups.so.2 is needed by qt-3.0.5-16 libpng12.so.0 is needed by qt-3.0.5-16
So then I tried:
[root@yeller rpms]# rpm -qa | grep libpng libpng-1.0.14-0.7x.3 libpng-devel-1.0.14-0.7x.3 [root@yeller rpms]# rpm -Uvh libpng-1.2.2-6.i386.rpm +libpng-devel-1.2.2-6.i386.rpmAnd I got another “failed dependencies” error. I've tried to resolve dependencies by working up from the lowest denominator, but I wind up in a spider web of RPMs that have more dependencies. So how do I install or upgrade without overwriting or losing something needed by something else?
—James Weisensee, firstname.lastname@example.org
Red Hat has created the up2date utility as an attempt to solve this problem. up2date requires that you register with Red Hat Network using the rhn_register command. up2date updates packages already installed on your system for which new versions have been released, most often relating to security patches. The rpm -qa commands you've tried are only querying your RPM database for packages already installed. If you want to find out which packages among a set of RPMs in a directory will provide a given file (such as libcups.so.2 or libpng12.so.0), then use a command more like:
for f in libcups.so.2 libpng12.so.0; do for i in *.rpm; do rpm -qpl | grep -q $f && echo $i; done done
to search each RPM package file listing for each of these filenames and to print the name of every package that contains said file(s). That won't always work (in some cases the desired file may be created by a package's postinstall script, for example). Also, some dependencies might not have filenames but are abstract identifiers that might be provided by any number of alternative packages.
—Jim Dennis, email@example.com
You often can get out of this kind of RPM upgrade mess by upgrading all the relevant RPMs at once, on the same command line. Just cursor up and keep adding the packages that RPM complains about to the rpm -Uvh command until it's happy. This works for removing codependent packages too.
—Don Marti, firstname.lastname@example.org
I recently installed Linux, but I receive the following error when I try to run executables on my system:
bash: a.out command not found
How do I fix this problem?
—Manuel Sevilla, email@example.com
Looks like the directory you're in is not in your PATH. To run your newly compiled C program from your current directory, use ./a.out.
—Robert Connoy, firstname.lastname@example.org
I have a router with a built-in printer server. How can I print using the printer connected to the printer port on the router?
—Carl Maklad, email@example.com
When an appliance has a built-in printer server, that generally means it offers support for a specific list of network printing protocols (such as the MS Windows SMB printing services and/or the traditional UNIX lpd services). Assuming that your router supports lpd (one of the oldest and simplest remote printing protocols), you should be able to configure your Linux system to use that device as a UNIX remote (lpd) print spool. If you're using Red Hat, try the printconf or printtool utilities.
—Jim Dennis, firstname.lastname@example.org
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
Free to Linux Journal readers.Register Now!
- SUSE LLC's SUSE Manager
- My +1 Sword of Productivity
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Non-Linux FOSS: Caffeine!
- Managing Linux Using Puppet
- Doing for User Space What We Did for Kernel Space
- Tech Tip: Really Simple HTTP Server with Python
- Parsing an RSS News Feed with a Bash Script
- SuperTuxKart 0.9.2 Released
- Rogue Wave Software's Zend Server
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide