Which Linux command or utility is simple, powerful, and surprisingly unknown to many people or used less often?
This could be a command or a piece of software or an application.
For example I’m surprised to find that many people are unaware of Caddy, a very simple web server that can make setting up a reverse proxy incredibly easy.
Another example is fzf. Many people overlook this, a fast command-line fuzzy finder. It’s versatile for searching files, directories, or even shell history with minimal effort.
netstat -tunlshows all open ports on the machine to help diagnose any firewall issues.Not powerful, but often useful,
column -taligns columns in all lines. EG$ echo {a,bb,ccc}{5,10,9999,888} | xargs -n3 a5 a10 a9999 a888 bb5 bb10 bb9999 bb888 ccc5 ccc10 ccc9999 ccc888 $ echo {a,bb,ccc}{5,10,9999,888} | xargs -n3 | column -t a5 a10 a9999 a888 bb5 bb10 bb9999 bb888 ccc5 ccc10 ccc9999 ccc888xargs
batcat
It’s like cat but better. Great for when you just want to look at the contents of a file, without loading a whole text editor.
Oh also, tldr
My procedure for learning how to use a cli command goes tldr page -> --help if the tldr fails to help me -> THEN the full manpage
ip eg:
# ip a # ip a a 192.168.1.99/24 dev enp160The first incantation - ip address (you can abbreviate whilst it is unambiguous) gets you a quick report of interfaces, MAC, IPs and so on. The second command assigns another IP address to an interface. Handy for setting up devices which don’t do DHCP out of the box or already have an IP and need a good talking to.
Oh and you can completely set up your IP stack, interfaces and routing etc with it. Throw in nft or iptables (old school these days - sigh!) for filtering and other network packet mangling shenanigans.
probably well known at this point but rsync is incredible and I use it all the time
Control+r == search through your bash history.
I used linux for ten years before finding out about that one.
Man
motion
After spending years dealing with shady freeware and junk software on windows, I was floored by how easy and nonchalantly I was able to set up a simple security camera on my PC
bcIt’s a simple command line calculator! I use it all the time.
kde connect
paste. I don’t think a lot of people know this command, but it can be handy at times
jq - super powerful json parser. Useful by hand and in scripts
I love jq, but I wouldn’t call it “surprising simple” for anything but pretty-formatting json. It has a fairly steep learning curve for doing anything with all but the simplest operations on the simplest data structures.
It’s not even pretty or accessible. 2-spaced indentation is incredibly hard to read.
jqandyqare both things I install on pretty much every machine I have.Combine with jc to process CSV files. This is how I get data into my plain text accounting system.
It can also format minimized JSON from cURL API requests
all of them
yesThe most positive command you’ll ever use.
Run it normally and it just spams ‘y’ from the keyboard. But when one of the commands above is piped to it, then it will respond with ‘y’. Not every command has a true -y to automate acceptance of prompts and that’s what this is for.
Also, you can make
yesreturn anything:yes noThat’s really neat but also seems like it could be quite dangerous in a lot of use-cases!
Absolutely, but when you do need it, it’s brilliant.
What’s the syntax here? Do I go
command && yes
I’m not sure if I’ve had a use case for it, but it’s interesting.
Also my favourite way to push a core to 100% CPU
yes > /dev/nullThat will just wait for
commandto finish properly and then runyes.What you want to run is
yes | command, so it spams the command with confirmations.For some cases I use “|| true”.
The idiom accepts that the preceding command might fail, and that’s OK.
For example, a script where mkdir creates a directory that might already exist.
truedelivers error level 0,falseerror level 1.yes && echo True || echo Falsewill always be True.false && echo True || echo Falsewill always be False.Common usage is for tools that ask for permissions and similiar.
yes | cp -ihas the same effect ascp --force(-i: prompt before overwrites).Sorry, I should have explained that. it’s
command | yesyes|command- Eg,yes|apt-get update(Not a great example since apt-get has -y, but sometimes that fails when prompting for new keys to accept)Edit: I got it backwards, thanks @lengau@midwest.social for the correction.
You’ve got it backwards - you need to pipe the output of
yesinto the input of the command:yes | command-that-asks-a-lot-of-questionsSo I did - thanks for the correction, edited.
