Problem: Spamassassin is not properly filtering domains such as link, click, xyz, science, and similar.
Solution: Your Registrar Boundaries file is out of date.
In Ubuntu, go to /usr/share/perl5/Mail/SpamAssassin/Util/
Use: wget svn.apache.org/repos/asf/spamassassin/trunk/lib/Mail/SpamAssassin/Util/RegistrarBoundaries.pm (It will probably download as RegistrarBoundaries.pm.1)
cp RegistrarBoundaries.pm to RegistrarBoundaries.pm.old
cp RegistrarBoundaries.pm.1 to RegistrarBoundaries.pm
sudo service spamassassin restart
Symptoms: Your system is susceptible to the Shellshock Patch, unless you have updated in the last two weeks, this is probably the case. This article applies to Linux based systems.
Solution: In Ubuntu, run sudo apt-get update, then run sudo apt-get install bash. This will update your system against the latest vulnerability.
If you are using centos, use yum.
Problem: You are trying to copy one directory to another directory.
Solution: sudo cp -a /yourdirectory/ . /destination/
same as -dR --preserve=all
How do I check my PHP or MySQL Version from the Ubuntu Command Line?
# php -v
# mysql -v
or for a better version use the package command:
# dpkg -l | grep ‘\(php\|mysql\)’
userdel is used in Unix / Linux systems to remove a user from the system.
-h –help; Display the help/man information and exit
-r –remove; this flag will remove the user’s home directory and associated mail. If the user is logged in or has processes running, this command will not work.
-f –force; force the removal of the user even if the user is logged in. This should only be used as a last resort as it could potentially damage your file systems.
SYNTAX: # userdel -r/-f/-h username.