In this tutorial we learn, how to convert rpm file into deb file.In Debian based OS like ubuntu the package file extension is .deb file. For installing the package in debian based OS we use the command dpkg -i package-name.deb .
In Red Hat based linux the package file extension comes in .rpm format .(RPM means Red Hat Package Manager).Sometimes there are some package which are available in rpm file. Hence for installing these package in Debain based OS we have to convert rpm file into deb file.

Follow the given below steps, to convert rpm file into deb file.

Login into Debian based OS (ubuntu/debian/linux mint etc). So here I am using Ubuntu machine for this practical

Step1 : Install alien package in Ubuntu

sudo apt-get install alien

Step 2 : Check if alien is installed or not

dpkg -l|grep alien

Step 3: Download any rpm file.
for eg.

wget ftp://centos.arcticnetwork.ca/pub/centos/6.4/os/x86_64/Packages/vsftpd-2.2.2-11.el6_3.1.x86_64.rpm

Step 4 : run the command , sudo alien package_name.rpm

linux@sharad:~/Desktop$ sudo alien vsftpd-2.2.2-11.el6_3.1.x86_64.rpm
[sudo] password for linux:
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
Warning: Skipping conversion of scripts in package vsftpd: postinst prerm
Warning: Use the –scripts parameter to include the scripts.
warning: vsftpd-2.2.2-11.el6_3.1.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
vsftpd_2.2.2-12_amd64.deb generated
linux@sharad-Lenovo-G570:~/Desktop$ ls
vsftpd-2.2.2-11.el6_3.1.x86_64.rpm vsftpd_2.2.2-12_amd64.deb
linux@sharad:~/Desktop$

Now you can see vsftpd_2.2.2-12_amd64.deb file is created

Step 6: Now you can install the .deb package with command, dpkg -i packag-name.deb

dpkg -i vsftpd_2.2.2-12_amd64.deb

Either creating the deb from rpm file .You can directly install the rpm with alien command also.

Use the command, alien -i package-name.rpm

sudo alien -i vsftpd-2.2.2-11.el6_3.1.x86_64.rpm