Best of Technical Support
I use Red Hat 5.0. When I try to execute files in a current directory, I get a “command not found” error even though the file exists and is executable. What is going on? —A. Roychowdhury
UNIX, like DOS and MS Windows, uses a PATH statement to tell it where to look for files. For security reasons, however, UNIX does not automatically add the current directory to the PATH when you enter a command (unlike DOS or MS Windows). You therefore need to specify the full path name of a command, even when you are in the directory in which the command is located. The easiest way to do that is to use the “dot-slash” notation; assuming you're in the directory where the Netscape executable lives, use:
You could add the current directory to your path, but most security experts agree that UNIX's default behaviour is a feature, not a bug, and should be left alone. Having UNIX automatically search the current path leaves you vulnerable to running non-standard versions of executables that could get you into trouble—imagine if someone dumped a program called ls into your current directory that actually mails your password file to someone else. —Vince Waldon, Vince.Waldon@iplenergy.com
I've been using OLL 1.1 for quite a while now without any problem. Lately, screwy things have been happening. One example is su. Whenever I use su to become a superuser from a regular user account, it prompts for the password, but ignores (and displays) whatever I type. It simply doesn't work; I have to CTRL-C out of it. I tried reinstalling to no avail.
Another problem that happens at the same time is with man pages. It displays the first page okay, but will not respond to any key presses except CTRL-C and other breaks. less just doesn't respond. Any help would be appreciated. Thanks. —Eric Benoit, Caldera OpenLinux Lite 1.1
Sounds like some kind of terminal setup problem—you may have changed /etc/termcap or the part of your .bash_profile or .bashrc that establishes the terminal type. Try any or all of the following commands:
% stty sane % reset % export TERM=vt100
—Scott Maxwell, firstname.lastname@example.org
Sometimes when I print from Netscape I get the following pop-up window: lpr: copy file too big. I am using Debian 1.3. How do I fix this? —Rick Bronson
The printer daemon enforces a limit on the size of the file it will print. The limit can be changed in your /etc/printcap by setting the mx value (0 means unlimited). For example:
Check man printcap for more details. —Alessandro Rubini, email@example.com
I recently installed the Caldera Linux kernel version 1.1 on my IBM ThinkPad 365XD. I want to install the X Window System, but I am not sure if it supports my computer's LCD, which is SVGA, 800x600, 60 Hz. The X configuration tool does not list this kind of LCD as an option. How can I install X? —John Gallagher
First, you should check if your video chip is supported by the latest version of XFree86. You can also check out the Linux Laptop page at http://www.cs.utexas.edu/users/kharker/linux-laptop/.
If your laptop is not supported, you can try commercial X servers such as Xi Graphics (http://www.xig.com/). —Pierre Ficheux, firstname.lastname@example.org
I am using Red Hat 5.0. I am having trouble getting rsh to work properly with other UNIX machines on my network. I either get “permission denied” or a password prompt. I thought the whole purpose of rsh was to issue commands on a remote system and have the output saved to file or wherever specified. What I am trying to do from my Linux machine is use rsh to connect to a Solaris machine, execute the command df -k, save the output to a file back on my Linux machine and disconnect. I can't seem to find any help in the man pages, so perhaps you could give me syntactical examples that might be of use. I administer both the host machines and the local Linux machines so I can create users, etc., if necessary. Thanks in advance for your help. —Don Kirouac
The Solaris rsh manual page will give you some information about the configuration files (/etc/hosts.equiv and $HOME/.rhosts). Actually, if your Linux machine is listed in the /etc/hosts.equiv or in the $HOME/.rhosts of the Solaris server, it should allow you to use a command such as:
rsh solaris_server df -k > foo
which executes df -k on Solaris and saves the result to the foo file on your SOLARIS home directory. For example:
$ rsh noe df -k > foo $ cat foo Filesystem kbytes used avail capacity Mounted on /dev/dsk/c0t0d0s0 13119 12932 0 100% / /dev/dsk/c0t0d0s6 195447 163746 12161 93% /usr /proc 0 0 0 0% /proc fd 0 0 0 0% /dev/fd /dev/dsk/c0t0d0s3 106047 55527 39920 58% /var swap 2242036 140 2241896 0% /tmp ...
—Pierre Ficheux, email@example.com
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!
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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