cat backupfile.tgz | gpg -c --cipher-algo=BLOWFISH > backupfile.tgz.gpg

(you’ll be asked for the Passphrase to use for encryption)
and for decryption:

cat backupfile.tgz.gpg |gpg -d --cipher-algo=BLOWFISH > backupfile.tgz

(you’ll be obviously asked for the Passphrase again, don’t forget it and save it in a safe place!)

To use it inside a script (batch process) the useful --passphrase switch
can be employed:

cat backupfile.tgz | gpg -c –cipher-algo=BLOWFISH --passphrase abcdefghi1234567890 > backupfile.tgz.gpg

in this case, do not forget to set 700 the file for avoiding unwanted reading…

~# for i in `mailq|grep '@' |awk {'print $1'}|grep -v '@'`; do postsuper -d $i ; done

Thomas Sewell from coolsewell.com contributed with this helpful notes:

you could also just do:

postsuper -d ALL

to clear all mail queues or even

postsuper -d ALL deferred

to just get rid of deferred mail from the queue.

Thanks Thomas! :)

There are many methods to backup your data on the fly, using rsync via ssh is one for example, but this post is about using netcat for a quick solution.

Listening side, where the backup data will be stored, or destination:

~# mkdir /whatever_the_name_of_your_backup_dir
~# cd !$
~# netcat -l -p 12345 | pv | tar xjf -

Sending side, where the original data are, or source:

~# cd /
~# tar cjf - --ignore-failed-read bin boot cdrom dev/ etc/ home/ initrd* lib/ root/ sbin/ usr/ var/ vmlinuz*  | pv | netcat -q 2 <YOUR_DESTINATION_IP> 12345

Don’t forget to create: /bin /media /mnt /opt /proc /selinux /srv /sys /tmp
and chmod 1777 /tmp
(This FHS is for a Debian Etch, please take care of different directories in your setup)

? () { echo "$*" | bc -l; }

Use like this:

bash$ ? 2*2
4

Thanks textsnippets.com