Softpanorama

May the source be with you, but remember the KISS principle ;-)
Contents Bulletin Scripting in shell and Perl Network troubleshooting History Humor

RHEL Tips

News

Linux Tips

Linux netwoking tips

Linux Start up and Run Levels

Suse Tips

Filesystems tips
Shell Tips Linux Start up and Run Levels VIM Tips GNU Tar Tips GNU Screen Tips Midnight Commander Tips and Tricks
RPM Tutorial Grub GNU Screen AWK Tips Humor Etc

There are several large collection of Linux Tips on the Internet. those are mixture of obsolete and useful tips so some work need to be done selecting valuable info from junk. Among them:

For YUM tips one can look at Yum - Linux@Duke Project Wiki

Linux Gazette regularly publishes tips column. See for example More 2 Cent Tips! LG #106

NEWS CONTENTS

Old News ;-)

[Feb 04, 2017] Restoring deleted /tmp folder

Jan 13, 2015 | cyberciti.biz

As my journey continues with Linux and Unix shell, I made a few mistakes. I accidentally deleted /tmp folder. To restore it all you have to do is:

mkdir /tmp
chmod 1777 /tmp
chown root:root /tmp
ls -ld /tmp
 
mkdir /tmp chmod 1777 /tmp chown root:root /tmp ls -ld /tmp 

[Feb 04, 2017] Use CDPATH to access frequent directories in bash - Mac OS X Hints

Feb 04, 2017 | hints.macworld.com
The variable CDPATH defines the search path for the directory containing directories. So it served much like "directories home". The dangers are in creating too complex CDPATH. Often a single directory works best. For example export CDPATH = /srv/www/public_html . Now, instead of typing cd /srv/www/public_html/CSS I can simply type: cd CSS
Use CDPATH to access frequent directories in bash UNIX
Mar 21, '05 10:01:00AM • Contributed by: jonbauman

I often find myself wanting to cd to the various directories beneath my home directory (i.e. ~/Library, ~/Music, etc.), but being lazy, I find it painful to have to type the ~/ if I'm not in my home directory already. Enter CDPATH , as desribed in man bash ):

The search path for the cd command. This is a colon-separated list of directories in which the shell looks for destination directories specified by the cd command. A sample value is ".:~:/usr".
Personally, I use the following command (either on the command line for use in just that session, or in .bash_profile for permanent use):
CDPATH=".:~:~/Library"

This way, no matter where I am in the directory tree, I can just cd dirname , and it will take me to the directory that is a subdirectory of any of the ones in the list. For example:
$ cd
$ cd Documents 
/Users/baumanj/Documents
$ cd Pictures
/Users/username/Pictures
$ cd Preferences
/Users/username/Library/Preferences
etc...

[ robg adds: No, this isn't some deeply buried treasure of OS X, but I'd never heard of the CDPATH variable, so I'm assuming it will be of interest to some other readers as well.]

cdable_vars is also nice
Authored by: clh on Mar 21, '05 08:16:26PM

Check out the bash command shopt -s cdable_vars

From the man bash page:

cdable_vars

If set, an argument to the cd builtin command that is not a directory is assumed to be the name of a variable whose value is the directory to change to.

With this set, if I give the following bash command:

export d="/Users/chap/Desktop"

I can then simply type

cd d

to change to my Desktop directory.

I put the shopt command and the various export commands in my .bashrc file.

How can I find information on the maximum amount of memory my system can handle

Red Hat Knowledgebase

The dmidecode command can be used to display information from the systems' BIOS that includes the maximum memory that the BIOS will support. This information is displayed by dmidecode as type 16 (Physical Memory Array) which can be filtered with the command dmidecode -t 16.

For instance, the following output shows a system that can support a maximum of 16GB of RAM.

Handle 0x0032, DMI type 16, 15 bytes
Physical Memory Array
	Location: System Board Or Motherboard
	Use: System Memory
	Error Correction Type: None
	Maximum Capacity: 16 GB
	Error Information Handle: Not Provided
	Number Of Devices: 4

Change your Hostname without Rebooting in RedHat Linux

Written by Tony Bhimani
September 8, 2005

Requirements
RedHat Linux (should apply to 7.x and up)

This tutorial covers changing your hostname in RedHat Linux without having to do a reboot for the changes to take effect. I've tested this on RedHat 7.3, 9, Fedora Core 3, and CentOS 4.1. It should work for all the versions in between since they all closely follow the same RedHat configuration. What's the point of this tutorial? Never reboot if you don't have to and keep your uptime intact.

Make sure you are logged in as root and move to /etc/sysconfig and open the network file in vi.

cd /etc/sysconfig
vi network

Look for the HOSTNAME line and replace it with the new hostname you want to use. In this example I want to replace localhost with redhat9.

HOSTNAME=redhat9

When you are done, save your changes and exit vi. Next we will edit the /etc/hosts file and set the new hostname.

vi /etc/hosts

In hosts, edit the line that has the old hostname and replace it with your new one.

192.168.1.110		redhat9

Save your changes and exit vi. The changes to /etc/hosts and /etc/sysconfig/network are necessary to make your changes persistent (in the event of an unscheduled reboot).

Now we use the hostname program to change the hostname that is currently set.

hostname redhat9

And run it again without any parameters to see if the hostname changed.

hostname

Finally we will restart the network to apply the changes we made to /etc/hosts and /etc/sysconfig/network.

service network restart

To verify the hostname has been fully changed, logout of your system and you should see your new hostname being used at the login prompt and after you've logged back in.

Quick, painless, and you won't lose your server's uptime.

Recommended Links

Softpanorama hot topic of the month

Softpanorama Recommended

Top articles

Sites

Top articles

Sites

20 Unix Command Line Tricks – Part I



Etc

FAIR USE NOTICE This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available in our efforts to advance understanding of environmental, political, human rights, economic, democracy, scientific, and social justice issues, etc. We believe this constitutes a 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit exclusivly for research and educational purposes.   If you wish to use copyrighted material from this site for purposes of your own that go beyond 'fair use', you must obtain permission from the copyright owner. 

ABUSE: IPs or network segments from which we detect a stream of probes might be blocked for no less then 90 days. Multiple types of probes increase this period.  

Society

Groupthink : Two Party System as Polyarchy : Corruption of Regulators : Bureaucracies : Understanding Micromanagers and Control Freaks : Toxic Managers :   Harvard Mafia : Diplomatic Communication : Surviving a Bad Performance Review : Insufficient Retirement Funds as Immanent Problem of Neoliberal Regime : PseudoScience : Who Rules America : Neoliberalism  : The Iron Law of Oligarchy : Libertarian Philosophy

Quotes

War and Peace : Skeptical Finance : John Kenneth Galbraith :Talleyrand : Oscar Wilde : Otto Von Bismarck : Keynes : George Carlin : Skeptics : Propaganda  : SE quotes : Language Design and Programming Quotes : Random IT-related quotesSomerset Maugham : Marcus Aurelius : Kurt Vonnegut : Eric Hoffer : Winston Churchill : Napoleon Bonaparte : Ambrose BierceBernard Shaw : Mark Twain Quotes

Bulletin:

Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 :  Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method  : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law

History:

Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds  : Larry Wall  : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOSProgramming Languages History : PL/1 : Simula 67 : C : History of GCC developmentScripting Languages : Perl history   : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history

Classic books:

The Peter Principle : Parkinson Law : 1984 : The Mythical Man-MonthHow to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Hater’s Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite

Most popular humor pages:

Manifest of the Softpanorama IT Slacker Society : Ten Commandments of the IT Slackers Society : Computer Humor Collection : BSD Logo Story : The Cuckoo's Egg : IT Slang : C++ Humor : ARE YOU A BBS ADDICT? : The Perl Purity Test : Object oriented programmers of all nations : Financial Humor : Financial Humor Bulletin, 2008 : Financial Humor Bulletin, 2010 : The Most Comprehensive Collection of Editor-related Humor : Programming Language Humor : Goldman Sachs related humor : Greenspan humor : C Humor : Scripting Humor : Real Programmers Humor : Web Humor : GPL-related Humor : OFM Humor : Politically Incorrect Humor : IDS Humor : "Linux Sucks" Humor : Russian Musical Humor : Best Russian Programmer Humor : Microsoft plans to buy Catholic Church : Richard Stallman Related Humor : Admin Humor : Perl-related Humor : Linus Torvalds Related humor : PseudoScience Related Humor : Networking Humor : Shell Humor : Financial Humor Bulletin, 2011 : Financial Humor Bulletin, 2012 : Financial Humor Bulletin, 2013 : Java Humor : Software Engineering Humor : Sun Solaris Related Humor : Education Humor : IBM Humor : Assembler-related Humor : VIM Humor : Computer Viruses Humor : Bright tomorrow is rescheduled to a day after tomorrow : Classic Computer Humor

The Last but not Least


Copyright © 1996-2016 by Dr. Nikolai Bezroukov. www.softpanorama.org was created as a service to the UN Sustainable Development Networking Programme (SDNP) in the author free time. This document is an industrial compilation designed and created exclusively for educational use and is distributed under the Softpanorama Content License.

The site uses AdSense so you need to be aware of Google privacy policy. You you do not want to be tracked by Google please disable Javascript for this site. This site is perfectly usable without Javascript.

Original materials copyright belong to respective owners. Quotes are made for educational purposes only in compliance with the fair use doctrine.

FAIR USE NOTICE This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available to advance understanding of computer science, IT technology, economic, scientific, and social issues. We believe this constitutes a 'fair use' of any such copyrighted material as provided by section 107 of the US Copyright Law according to which such material can be distributed without profit exclusively for research and educational purposes.

This is a Spartan WHYFF (We Help You For Free) site written by people for whom English is not a native language. Grammar and spelling errors should be expected. The site contain some broken links as it develops like a living tree...

You can use PayPal to make a contribution, supporting development of this site and speed up access. In case softpanorama.org is down you can use the at softpanorama.info

Disclaimer:

The statements, views and opinions presented on this web page are those of the author (or referenced source) and are not endorsed by, nor do they necessarily reflect, the opinions of the author present and former employers, SDNP or any other organization the author may be associated with. We do not warrant the correctness of the information provided or its fitness for any purpose.

Last modified: September, 18, 2017