Command-line partitioning and formatting

Automatic non-interactive formatting in Linux is possible with parted.
The following creates 1 single ext3 partition on an entire disk. Of course, if you assign the wrong disk to the $disk variable, it will be a bad day...

# Select the disk device and chose a label for the partition
# ptype=msdos for disks up to 2 TB. ptype=gpt for disks over 2 TB
disk=/dev/sdx; label=my_part_label; ptype=msdos

I have added sleep commands, so I can just copy/paste the whole thing and still have a chance to Ctrl-C if I change my mind at the last second.

# print the current partition(s) state
parted $disk print ; sleep 10

# create a gpt ot msdos partition table (depending on $ptype variable defined above)
parted -a optimal $disk mklabel $ptype ; sleep 5

# create the partition, starting at 1MB which may be better
# with newer disks
parted -a optimal -- $disk unit compact mkpart primary ext3 "1" "-1" ; sleep 5

# format it
mke2fs -j -v -L "$label" ${disk}1 && echo "OK. That's it"

Update: see also scripting disk partitionning in Linux - take 2 for another way, using sgdisk instead of parted.