This command will import all the MySQL sql dumps in the current folder. You can use this to restore your backuped databases.

for i in *; do mysql -uroot `basename $i .sql` < $i;  done

Configure the default gateway

route add -net 0/0 gw IP_Gateway

See what your users are doing using SSH connected to your system - this will show you what happens on the first console. If someone is typing, you’ll be able to get an output of his keystrokes. Substitute cat /dev/vcs1 with cat /dev/vcs2 or cat /dev/vcs3 and so on for other consoles.

cat /dev/vcs1

Original Article

Show link status of all interfaces

ip link show

An easier way to batch convert images using the ‘convert’ command…

#!/bin/sh
# An Easy command to use the convert command. Makes sure that the rename problem don't happen

if [ ! -d "Out" ]; then
        mkdir Out
fi

sel="*.*"
if [ $# -eq 2 ] ; then
        sel=$2
fi

for i in $sel; do
        echo -n "Converting $i ... "
        convert $1 $i Out/$i
        echo "Done"
done

Rip audio tracks from a CD to wav files

cd-paranoia -B

Burn a compressed ISO image

gzip -dc cd_iso.gz | cdrecord dev=/dev/cdrom

Show all deb packages with the name “httpd”

dpkg -l | grep httpd

Shows all partitions on the HDD

fdisk -l

Upgrade a rpm package only if it is already installed

rpm -F package.rpm