wader / catgolf

cat(1) golf

cat(1) golf

Get the file to stdout as intact as possible.

Pure league

• No shell features are involved.
• Only outputs to stdout.

cat file.txt
awk 1 file.txt
paste file.txt
pv -q file.txt
pr -t file.txt
sed b file.txt
grep ^ file.txt
grep $ file.txt
sed '' file.txt
grep '' file.txt
sort -m file.txt
look '' file.txt
jq -rR . file.txt
sed -n p file.txt
cut -b 1- file.txt
jq -jRs . file.txt
perl -pe1 file.txt
tail -n +1 file.txt
head -n -0 file.txt # GNU head
cp file.txt /dev/fd/1
gcc -E -P -xc file.txt
scp file.txt /dev/fd/1
column -t -l 1 file.txt
comm file.txt /dev/null # BSD comm
w3m -dump_source file.txt
dd status=none if=file.txt # GNU dd
hexdump -ve '"%c"' file.txt
split --filter=tee file.txt # GNU split
join -a 1 file.txt /dev/null
openssl enc -none -in file.txt
curl file:///proc/self/cwd/file.txt
git -P grep --no-index -h ^ file.txt
shuf --random-source=/dev/zero file.txt
bat --color=never --style=plain file.txt
diff --line-format=%L /dev/null file.txt
vim -es --clean '+w! /dev/fd/1' '+q!' file.txt
python -c 'print(open("file.txt").read()[:-1])'
ffmpeg -v quiet -f data -i file.txt -map 0:0 -c text -f data -
emacs -Q --batch --eval '(princ (with-temp-buffer (insert-file-contents "file.txt") (buffer-string)))'

Shell league league

• Can use shell feature like pipes, redirect etc to work.

tee < file.txt
tr a a < file.txt
rev file.txt | rev
tac file.txt | tac
echo ',p' | ed -s file.txt
xxd -p file.txt | xxd -p -r

Brittle league

• May not handle every character.
• May not handle every file length.

sed '/*/p' file.txt
gcc -E -P -xc file.txt

Error league

• Same as "Pure league", but errors on stdout and/or stderr are acceptable.

dd if=file.txt
gcc -xc file.txt

Junk league

• Same as "Error league", but most of the output bytes are from the file.

m4 file.txt # Does not handle lines that starts with `#` or looks like definitions.
fold file.txt # Works for files without long lines
wall -n file.txt # I hope your file doesn't have any secrets
uniq -Dw0 file.txt # Doesn't work for single-line files
xargs -d\n -a a.txt echo # Ends up with a trailing newline
more -e -n 65535 file.txt # Works for files with less than 65k lines.
nl -bn -w 1 -s '' file.txt # Each line has an extra space

catgolf's Issues

Broken sed '/*/p'

In #1, @Doctor-love added

sed '/*/p' file.txt

But this duplicates lines containing the * character. E.g.:

$ printf '*hello*\nworld!\n' > file.txt
$ cat file.txt
*hello*
world!
$ sed '/*/p' file.txt
*hello*
*hello*
world!

There's now another sed call that is shorter and works correctly, so IMHO this one should be removed.

Clarify rules

The rules are a bit unclear to me. Are non-pipe sequences of two commands allowed (as in foo file.txt; bar)? If so, I have one.

Broken gcc

In #9, @kotborealis added a gcc command, but this doesn't quite work with arbitrary files.
For example:

$ cat README.md | wc -l
44

$ gcc -E -P -xc README.md | wc -l
README.md:1:3: error: invalid preprocessing directive #cat
    1 | # cat(1) golf
      |   ^~~
35

While it's an interesting hack, I don't think it belongs in the "Pure league".