Sometimes, you might required to compress or extract .rar file from Linux box which do not come by default, however you may install it manually.
Under Debian Linux, you need to type apt-get as follows to install unrar program:
apt-get install unrar
Under Fedora core Linux then use yum command
yum install unrar
If the above method not working, you may copy the following command and paste to your console line.
cd /tmp;wget http://www.rarlab.com/rar/rarlinux-3.6.0.tar.gz;tar zxf rarlinux-3.6.0.tar.gz;cd rar;cp rar unrar /bin