ctrl+r on bash will let you quickly search and execute previous commands by typing the first few characters usually.

it’s much more of a game changer than it first meets the eye.

I use $_ a lot, it allows you to use the last parameter of the previous command in your current command

mkdir something && cd $_

nano file
chmod +x $_

As a simple example.

If you want to create nested folders, you can do it in one go by adding -p to mkdir

mkdir -p bunch/of/nested/folders

Good explanation here:
https://koenwoortman.com/bash-mkdir-multiple-subdirectories/q

Sometimes starting a service takes a while and you’re sitting there waiting for the terminal to be available again. Just add --no-block to systemctl and it will do it on the background without keeping the terminal occupied.

systemctl start --no-block myservice

ripgrep

cd `pwd`

for when you want to stay in a dìr that gets deleted and recreated.

cat /proc/foo/exe > program
cat /proc/foo/fd/bar > file

to undelete still-running programs and files still opened in running programs

nc is useful. For example: if you have a disk image downloaded on computer A but want to write it to an SD card on computer B, you can run something like

user@B: nc -l 1234 | pv > /dev/$sdcard

And

user@A: nc B.local 1234 < /path/to/image.img

(I may have syntax messed up–also don’t transfer sensitive information this way!)

Similarly, no need to store a compressed file if you’re going to uncompress it as soon as you download it—just pipe wget or curl to tar or xz or whatever.

I once burnt a CD of a Linux ISO by wgeting directly to cdrecord. It was actually kinda useful because it was on a laptop that was running out of HD space. Luckily the University Internet was fast and the CD was successfully burnt :)

parallel, easy multithreading right in the command line. This is what I wish was included in every programming language’s standard library, a dead simple parallelization function that takes a collection, an operation to be performed on the members of that collection, and optionally the max number of threads (should be the number of hardware threads available on the system by default), and just does it without needing to manually set up threads and handlers.

inotifywait, for seeing what files are being accessed/modified.

tail -F, for a live feed of a log file.

script, for recording a terminal session complete with control and formatting characters and your inputs. You can then cat the generated file to get the exact output back in your terminal.

screen, starts a terminal session that keeps running after you close the window/SSH and can be re-accessed with screen -x.

Finally, a more complex command I often find myself repeatedly hitting the up arrow to get:

find . -type f -name '*' -print0 | parallel --null 'echo {}'

Recursively lists every file in the current directory and uses parallel to perform some operation on them. The {} in the parallel string will be replaced with the path to a given file. The '*' part can be replaced with a more specific filter for the file name, like '*.txt'.

systemd-run lets you run a command under some limitations, ie

systemd-run --scope -p MemoryLimit=1000M -p CPUQuota=20% ./heavyduty.sh

rpm-ostree status

rpm-ostree reset

rpm-ostree rebase

idk i love rpm-ostree man

Journalctl | grep -C 10 'foo' was useful for me when I needed to troubleshoot some fstab mount fuckery on boot.

Ha! Remember back when there was no fstab fuckery? Good times. But you have a massive init blob slowly eating other services and replacing them with shitty replicants like this embarrassment (ohai root NFS) and all of us Unix people are chuckling in our reduced-fuckery ‘hell’.

echo 'dXIgbW9tCmhhaGEgZ290dGVtCg==' | base64 -d

Running Wine is the command I’ve used the most probs, you can tell I haven’t touched the thing in months.

Something that really improved my life was learn to properly use find, grep, xargs and sed. Besides that, there are these two little ‘hacks’ that are really handy at times…

1- find out which process is using some local port (i.e. the modern netstat replacement):

$ ss -ltnp 'sport = :<port-number>'

2- find out which process is consuming your bandwidth:

$ sudo nethogs

when I forget to include sudo in my command:

sudo !!

Ctrl-z to suspend the running program.

bg to make it continue running in the background.

jobs to get an overview of background programs.

fg to bring a program to the foreground.