ahh
~$ which cat
For the past 30 years or so, my brain always tells me to type “last” instead of “tail”. This usually results in some kind of “Permission denied” message that confuses me for a few seconds.
there’s a last command? just knowing that.
I was today’s years old to finally notice the cat-head-tail thing…
But it also just recently dawned upon me why pacman has those weird “c” as progress indicators…
I’m not a smart man…
Bat is my favorite command to date.
~$ which bat ~$ bat man
tac
I’ve always wondered what a good use case for tac would be…
Reverse chronological order, mostly
tac log.txt |head # would give you newest first
no good for sort because sort already supports -r
no need it for tail on large files because tail already skips to the end.
I do a lot of impromptu bash to sus crap out of logs.
when you’re balls deep in
cat log|grep -v foo| rev|cut -f 1-3 -d \ | |rev
Sometimes tac comes in clutch.
That’s fair. I’d usually just use less and drop to the end. My use cases would always need the older log before a newer log though because that’s the start of the problem. At least that’s how I operate.
catis misunderstood a lot. The purpose of cat is to combine multiple files together (it’s literally short for “concatenate”), likecat *.logto combine all log files together.If you’re just using it for a single file, then you should just redirect the file to stdin. These two command lines behave similarly:
cat foo.txt | some-commandsome-command < foo.txtFor
head,tail,grepand some other commands, you can just pass in the file name directly as an argument (e.g.grep whatever foo.txt).Also known as cat abuse.
awww what’s a cat without a head and a tail?
I guess depending on your interpretation of without it could either be “cat” or “a”.
A kernel?
uhmm no
Fair, but in general I find it way more useful to use cat for piping.
In most cases I’ll do something like
cat file | program cat file | program | grep cat file | program | grep | cutThis gets more complicated if the file is at the end of the command.
It wouldn’t be at the end, since you’d still be piping into
programprogram <file | grep | cutAnd
<file program | grep | cutworks tooOh, thanks! Didn’t know that
Thanks - I didn’t know this either!
You’ll see
cat FILE |all the time because it’s just a natural start to a pipeline. Youcat FILEto see the content unfiltered before filtering it with further commands.it’s just a natural start to a pipeline
If I just want to look at the file, is there a better way than
cat foo.txt? I guess I can’t just do< foo.txtAdmittedly I still use
catfor this.This also works too, but it’s more verbose:
echo "$(<foo.txt)"It’s mentioned in the Bash man pages:
The command substitution $(cat file) can be replaced by the equivalent but faster $(< file).
how in the world is this not a useless use of echo and equivalent to
<foo.txtOK, TIL you can just do
<foo.txt. I didn’t think that worked. Thanks!
So close! you have to do
cat < foo.txt:-) (/s)You can use
less. There are also specialized ones for that purpose like bat.
yeah sure but the command is literally written for the humor.
I know, but I just wanted to mention this since a lot of new Linux users end up using cat this way :)
Is there any downside?
deleted by creator
ohhh but it’s all humor that’s the point of the post.
I mean as a new Linux user, I won’t take anything from a humor group seriously.
I would.
I’d be careful of jokes, sure, but geeks often can’t help have real discussions. Like in this very thread
I still like doing
cat file.txt | grep thingbecause I often re-run it to find something else likecat file.txt | grep thing2- and if I do that with grep, the pattern sits awkwardly in the middle instead of at the end< file.txt grep thingalso works.is it more obtuse
Another all-time favorite:
$ man woman No manual entry for woman$ touch woman touch: cannot touch 'woman': Permission denied
I always thought it’s
head | cat | tailIt, of course, waits for an input, which brings up the one and only question…
Have you fed your cat?
of course look meow meow so loud
I’ve been using a slightly customized bash-cat for years now. Still makes me smile when I see it
last commit message: “Shorter Cat with added Tail.”
yeah I just checked it out it’s cute
tacis a cat but faced the other wayohhh let me check it out lol
man whichwhereis cat?
which catwhatis cat?
man catlocate cat
rtfm
Be careful now, 2000/2010 Linux terminology can be taken as an insult in 2026. /s
I’m tired of this stupid coddling bullshit with the influx of new Linux users. If you can’t read don’t use Linux. Simple. 😂
