Stumbled across this site in almost a creepy way. I was going through my old work computer and had a trillion shell scripts that did god(dess) knows what. One of them was titled simply short_names with no file ext and bc it was red had been chmod +x'd' at some point lol.
# All possible combinations of 4 letters,
# each on one line for streaming and in random order
combinations="$(echo {a..z}{a..z}{a..z} | tr " " "\n" | shuf)"
echo "possibilities: $(echo "$combinations" | wc -l)"
# Filter to only names that 404 on github.com,
# 10 in parallel (might still take a while),
# and write them to a file
echo "$combinations" | xargs -P10 -I{} sh -c "curl -sfI https://github.com/{} > /dev/null || echo {}" > github.txt
echo "available on Github: $(wc -l github.txt)"
# Do the same thing for twitter.com
cat github.txt | xargs -P10 -I{} sh -c "curl -sfI https://twitter.com/{} > /dev/null || echo {}" > github-twitter.txt
It takes about 15 minutes to execute and then writes a file github.txt which as of yesterday was 10,500 lines of available names on both github & twitter. This site does the same thing but for like 100+ platforms. It spits out a txt file like this, with some of these working and some not—s/o to creatrice https://jorin.me/find-short-usernames. I love a util.
17433 │ psz
17434 │ zbg
17435 │ ttc
17436 │ mid
17437 │ mnl
17438 │ uxn
17439 │ okq
17440 │ msp
17441 │ vmt
17442 │ hnu
17443 │ bvt
17444 │ inh
17445 │ bwo
17446 │ jmy
17447 │ gzw
17448 │ lkg
17449 │ kdo
17450 │ opy