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Ubuntu: SSH - Change Welcome Message PDF Print E-mail
Tech Notes - Linux
Written by Rick   
Wednesday, 24 June 2009 00:00

Have you ever tired of seeing the standard SSH welcome message (a.k.a. banner)? Does it provide too much information about the system creating a security concern? If your answer to either of these questions is "Yes", then read on.

Changing the message is relatively easy. Simply modify motd. The file is located in /var/run on my system. Other information I've found suggests the file is located in /etc. I do have a shortcut from /etc to the file in /var/run so either location may be valid depending upon your release version of Ubuntu.

If you also wish to remove the "Last Login" information line, you 'll need to modify one other file (though not recommended). Edit /etc/ssh/sshd_conf. Locate and change the line "PrintLastLog yes" to "PrintLastLog no". Restart the ssh daemon (sudo /etc/init.d/ssh restart).

 

 
Ubuntu 9.04: Enable NumLock in KDM PDF Print E-mail
Tech Notes - Linux
Written by Rick   
Friday, 05 June 2009 17:00

I've tried following instructions found on the 'net for turning on the NumLock key at startup in KDE. Only problem; I don't have the keyboard element installed for some reason. So I'm trying the KDM solution;

 

Edit /etc/kde4/kdm/Xsetup. Add the following lines;

if [ -x /usr/bin/numlockx ]; then
/usr/bin/numlockx on
fi
 
Ubuntu 9.04: Location of User's Crontab File PDF Print E-mail
Tech Notes - Linux
Written by Rick   
Thursday, 14 May 2009 07:31

The location of a user's crontab file, in Linux, varies from distribution to distribution. It can even vary in different releases of a distribution. In Ubuntu (and variants) for release 9.04 the location is;

/var/spool/cron/crontabs

The user's crontab will be titled by the user's name.

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Linux CLI: MySQL Backup & Restore PDF Print E-mail
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Tech Notes - Linux
Written by Rick   
Tuesday, 12 May 2009 18:00

Backing up and restoring a MySQL database is a relatively easy proposition provided you have adequate access priviledges to the database. The following commands write and read to the current directory. You'll also need sufficient access priviledges in your current directory to execute these. Note:Italic words are user variables.

 

Backup (a.k.a. Dump)

$ mysqldump -u username -p databasename > outputfile.sql

 

Restore

$ mysql -u username -p --database=databasename < outputfile.sql

 

That's it, short and sweet. Told ya it was easy!

 

 
Kubuntu 9.04: Fix the Ugly Firefox Widgets PDF Print E-mail
Tech Notes - Linux
Written by Rick   
Thursday, 07 May 2009 08:00

I've been using Kubuntu for some time. I don't recall when, but at some point the form controls got ugly in Firefox. Radio buttons, check boxes and the like.

I tried all the stuff in the forums. The firefox-forms-widget fix to no avail. After searching I finally ran across someone who had the answer, Larsn.

Here's the fix that worked for me. Essentially Larsn's answer slightly modified for Jaunty with KDE 4.2;

The fix that worked for me is to install the package “gtk2-engines-qtcurve”, then open K-Start/System Settings and go to Appearance -> GTK Styles and Fonts change the GTK Styles to Use another Style: “QtCurve”.

I tested this with a couple other options like "Crux". It also worked. I'm guessing it's an issue with the Oxygen theme.

 
CLI: Insert/Replace Text in Multiple Files PDF Print E-mail
Tech Notes - Linux
Written by Rick   
Friday, 12 December 2008 09:43

 

For the past day or so I've been working through issues to add/change or delete strings in multiple files. As usual there is plethora of methods to do try. Each have a place in an administrator's arsenal.

Using Perl or SED

These methods are suited for text manipulation where search and replace strings are simple without the need for escape characters;

In the following example we replace the word rabbit with the word blueberry in all html files in the current directory;

perl -p -i -e "s/rabbit/blueberry/g" *.html
sed 's/rabbit/blueberry/g' *.html

Of course, there are an abundance of switches that can be used to accomplish more tasks like backing up files before actually executing the search replace function. Check the man pages for more details.

Using RPL

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