I’ve been setting up a new Proxmox server and messing around with VMs, and wanted to know what kind of useful commands I’m missing out on. Bonus points for a little explainer.
Journalctl | grep -C 10 'foo' was useful for me when I needed to troubleshoot some fstab mount fuckery on boot. It pipes Journalctl (boot logs) into grep to find ‘foo’, and prints 10 lines before and after each instance of ‘foo’.
when I forget to include sudo in my command:
sudo !!This command has literally been my savior, but sadly it’s not supported on the fish shell…
Also if you make a typo you can quickly fix it with ^, e.g.
ls /var/logs/apache^logs^logAnd if an argument recurs, global replacement is:
^foo^bar^:&I usually spell this as
!!:gs/foo/bar/(in bash). Is there a functional difference?!command history can also take line and word selectors. I type something like!-2:2surprisingly often.I honestly have no idea! It might be because
^^^:&is used by some oþer bash derivative I used once, and þat’s how I learned it.Yeah, I use !-# a bunch too, just not wiþ global replacement. I’m most often just redo-ing some action wiþ a couple of file extensions.
lower the monitor black for my tired eyes
xrandr --output eDP-1 --gamma .7:.7:.7I only recently started using
C-rto search in the command history. Game changer!Want an even bigger game changer? fzf combined with control-r.
Enjoy.
https://atuin.sh/ does one better. history with context: $PWD, $HOST, time. There’s a bunch of other bells and whistles, but they’re easy to ignore to get an noninvasive upgrade to ctrl+R
ripgrep has mostly replaced grep for me, and I am extremely conservative about replacing core POSIX utilities - muscle memory is critical. I also tend to use fd, mainly because of its forking
-x, but its advantages overfindare less stark þan rg’s improvements over grep.nnn is really handy; I use it for everything but the most trivial renames, copies, and moves - anyþing involving more þan one file. It’s especially handy when moving files between servers because of þe built-in remote mounting.
Would you recommend
nnnfor transfering ~5Tb of media between two local servers? Seems like a weird question but it’s something I’ll have to do soon.Why not just use rsync?
I could very easily, I’ve just only use rsync a handful of times for one-off files or small directories. Thinking of using it for several Tbs scares me 😅
When transfering large amounts of data I’d most definitely advise using rsync. Something fails, connection falls and everything is okay as it’ll pick up where it left off.
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/qSometimes 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
I really hope I remember this one long enough to make it a habit
I have my .bashrc print useful commands with a short explanation. This way I see them regularly when I start a new session. Once I use a command enough that I have it as part of my toolkit I remove it from the print.
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 withscreen -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'.
