Best of Technical Support

Our experts answer your technical questions.
Execution Trouble

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:

$ ./netscape

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

su

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, maxwell@pacbell.net

Printing from Netscape

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:

lp:lp=/dev/lp1:sd=/usr/spool/lpd:mx#10000

Check man printcap for more details. —Alessandro Rubini, rubini@linux.it

Installing X Windows on an IBM ThinkPad

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, pierre@lectra.com

rsh

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, pierre@lectra.com

______________________

Comments

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

error in linux enterprise edition 4.0 while using commands

vsrikanth's picture

while using some commands in redhat linux 4.0, commands like ls, df, cat etc i am getting error
this is the error when i type ls with user root
ls: error while loading shared libraries: ÿEj: cannot open shared object file: No such file or directory

for df command i get error as segmentation fault and i get a mail for root /var/mail as follows
[root@oraapp1 mail]# tail root
To: root@oraapp1.dchronicle.com
Subject: Cron /usr/lib/sa/sa1 1 1
X-Cron-Env:
X-Cron-Env:
X-Cron-Env:
X-Cron-Env:
X-Cron-Env:

date: error while loading shared libraries: ÿÄ SjèkóÿÿÄÂRè,ÿÿÿj: cannot open shared object file: No such file or directory
what is the problem.

Webinar
One Click, Universal Protection: Implementing Centralized Security Policies on Linux Systems

As Linux continues to play an ever increasing role in corporate data centers and institutions, ensuring the integrity and protection of these systems must be a priority. With 60% of the world's websites and an increasing share of organization's mission-critical workloads running on Linux, failing to stop malware and other advanced threats on Linux can increasingly impact an organization's reputation and bottom line.

Learn More

Sponsored by Bit9

Webinar
Linux Backup and Recovery Webinar

Most companies incorporate backup procedures for critical data, which can be restored quickly if a loss occurs. However, fewer companies are prepared for catastrophic system failures, in which they lose all data, the entire operating system, applications, settings, patches and more, reducing their system(s) to “bare metal.” After all, before data can be restored to a system, there must be a system to restore it to.

In this one hour webinar, learn how to enhance your existing backup strategies for better disaster recovery preparedness using Storix System Backup Administrator (SBAdmin), a highly flexible bare-metal recovery solution for UNIX and Linux systems.

Learn More

Sponsored by Storix