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.
socat- connect anything to anythingfor example
socat - tcp-connect:remote-server:12345socat tcp-listen:12345 -socat tcp-listen:12345 tcp-connect:remote-server:12345I think a lot of people don’t realise that yt-dlp works for many sites, not just YouTube
I used it recently for watching a video from tiktok without having to use their god awful web UI and it was amazing
It also supports ripping playlists. Fantastic to archive a set locally…
Since everyone keeps mentioning yt-dlp I gotta ask: what’s wrong with the original youtube-dl? I keep using it, it works, it’s still being updated.
yt-dlp has sponsorblock features, youtube-dl does not.
Also works on Twitch with the added benefit of NOT playing ads (you still get breaks, just with a placeholder screen instead of the commercial).
mpv has yt-dlp support built in, so it can just play the streams directly.
Wait how?
I just run
mpv $URLThis is the only way to watch twitch
With their huge, clunky UI and my 1080p screen, yeah it is.
Not powerful, but often useful,
column -taligns columns in all lines. EG$ 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 ccc888wait, shell could make matrix multiplication ?
No, that’s just brace expansion.
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.
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 noI… did not know that. Thanks, TIL!
That’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.
That 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.Also my favourite way to push a core to 100% CPU
yes > /dev/nullhow is that better than
cat /dev/zero > /dev/nullor
while true; do :; doneWho said it was better? It’s just my favourite.
Like my favourite shirt, it’s no better than the others, but it brings me a little joy :)
- on a serious note though, thank you for sharing your two examples - I didn’t know they existed.
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.
mkdir -pwill not complain if the dir existsRight, it was an example of a pattern. In that case, -p could be used.
I figured as much. Just wanted to show another option.
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-questions
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.
Pandoc.
Converts any rich text format to any other.
Man
xargs
Very true. I used to do magic with xargs when working as a sysadm. Also a good way to mess up on a grand scale. Ask me how I know.
So, how do you know?
By not testing it properly before running it over the whole file system resulting in a few hours of extra work cleaning up the mess I made.
Control+r == search through your bash history.
I used linux for ten years before finding out about that one.
grep goes crazy if you know your regex
nmap *your_local_ip_address*for example
nmap 192.168.1.43/24will show you what devices are connected to the local network, and what ports are open there. really useful, for example, when you forgot the address of your printer or raspi yet again.you can also use it to understand what ports on your computer are open from an attacker’s perspective, or simply to figure out what services are running (ssh service).
netstat -tunlshows all open ports on the machine to help diagnose any firewall issues.netstat is kind of deprecated,
ssis more modern (from the iproute2 package) and uses very similar parameters.
vd(VisiData) is a wonderful TUI spreadsheet program. It can read lots of formats, like csv, sqlite, and even nested formats like json. It supports Python expressions and replayable commands.I find it most useful for large CSV files from various sources. Logs and reports from a lot of the tools I use can easily be tens of thousands of rows, and it can take many minutes just to open them in GUI apps like Excel or LibreOffice.
I frequently need to re-export fresh data, so I find myself needing to re-process and re-arrange it every time, which visidata makes easy (well, easier) with its replayable command files. So e.g. I can write a script to open a raw csv, add a formula column, resize all columns to fit their content, set the column types as appropriate, and sort it the way I need it. So I can do direct from exporting the data to reading it with no preprocessing in between.
probably well known at this point but rsync is incredible and I use it all the time
