Generating a alphabetical list of Linux commands

03/26/2017 • 2 minute read

I was out at lunch with a friend who has been interviewing for Senior Linux Engineer positions, and he mentioned one of the interview problems he had was this:

Write down a list of Linux commands for each letter in the alphabet

Pretty easy for someone with 20+ years experience, but the interesting aspect to this question was that they said they asked this because “It was impossible to program out an answer”

I was immediately skeptical as there has been very few things I haven’t been able to eventually script out.

Sure enough, it was a very simple one-liner when I remembered the compgen built-in:

for i in {a..z}; do compgen -c "$i" | shuf -n 1; done

Will generate a random list of commands A-Z. For one example:

apt-cdrom
bluez-test-audio
cpgr
dmsetup
expr
from
gnome-thumbnail-font
hpljP1007
iptables-xml
jockey-text
koi8rxterm
lodraw
mcomp
nm-tool
orca
pod2text
quote_readline
readlink
sleep
totem-video-indexer
ucfq
validlocale
wmctrl
xzcat
yelp
zgrep

I would have preferred to stick to only built-ins, but you wouldn’t have been able to complete the problem that way:

$ for i in {a..z}; do compgen -b "$i" | shuf -n 1; done
alias
bind
cd
disown
export
fg
getopts
hash
jobs
kill
local
mapfile
popd
read
shift
trap
unalias
wait

So apparently there are no built-ins starting with “I,N,O,Q,V,X,Y,Z”. Now that would have been a hard interview question.

Generating a alphabetical list of Linux commands

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