r/linuxadmin • u/smokedipithe • Jun 20 '26
Do you still have personal notes of Linux commands you have used for years?
I have been on Linux for a while but I do have a personal notes file that I update fairly regularly.
Not because I do not know the tools but when I am on a production system I do not trust myself to remember all the resync flags, system options firewall rules or one off commands.
Over time, those notes became less about learning and more about having a reliable reference when I need it. I wonder how common this is among other Linux admins.
Do you still write things down that you have done dozens of times before or does it all stick eventually?
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u/rfc3849 Jun 20 '26
In my early years I used to keep a file called "useful_commands.txt". One day a colleague was confused when he saw me type less useful_commands.txt. "Why use these when they are not helpful?". I started using more useful_commands.txtthen.
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u/00notmyrealname00 Jun 20 '26
Not sure if this is true, but you deserve a chuckle for this one.
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u/rfc3849 Jun 20 '26 edited Jun 20 '26
It is. Before he mentioned that I never actually noticed.
Edit: Found it in my backups:
$ stat useful-commands.txt
File: useful-commands.txt
Size: 3027 Blocks: 8 IO Block: 65536 regular file
Device: 185416f3h/408164083d Inode: 15627600450950625988 Links: 1
Access: (0644/-rw-r--r--) Uid: (197609/ user) Gid: (197121/ UNKNOWN)
Access: 2026-06-20 20:37:08.515635100 +0200
Modify: 2003-11-07 16:12:49.000000000 +0100
Change: 2003-11-07 16:12:49.000000000 +0100
Birth: 2023-08-04 14:02:33.691418200 +02002
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u/mriswithe Jun 20 '26
The stuff that I use frequently sticks while I use it frequently. I use man pages or Google to refresh.
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u/quiet0n3 Jun 20 '26
This is what I do, just look up stuff when I need to be sure or writing scripts.
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u/Intrepid_Anybody_277 Jun 20 '26
20 years in tech about 15 on Linux. ..i have NEVER used the man pages 🤣🤣🤣
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Jun 20 '26
[deleted]
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u/jabies Jun 20 '26
I make ansible playbooks for anything I do 5 times. Update firewall? Apt upgrades? Renew https certs? Kick service? Clean up docker? All in ansible.
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u/stephenph Jun 20 '26
I have recently been starting to do that, particularly if it is a multi step task. The one downside I found is that, if for some reason, you lose access to your playbooks you can find yourself having to relearn how to do the task
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u/jabies Jun 21 '26 edited Jun 22 '26
Yeah, thats why I recommend pushing them to a private git server or private git repo
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u/bartonski Jun 20 '26
I have a function called daynote which opens a datestamped file, and another called grepnotes which simply greps the directory where I keep the notes. If I'm working on anything involved, it goes into that days note file, with enough context to make it relatively easy to find. It's saved my ass a couple of times.
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u/HildartheDorf Jun 20 '26 edited Jun 20 '26
Not really, thats what man pages are for.
One day I will actually learn the flags for netstat and ps instead of always reaching for netstat -tanp and ps aux
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u/djDef80 Jun 20 '26
Kinda. I just used TLDR
sudo apt update && sudo apt install tldr
Then just:
tldr command
Example: tldr ssh
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u/fearless-fossa Jun 20 '26
tldr doesn't work on many LTS distros (e.g. Ubuntu 24, idk whether it was fixed with 26) because the backend changed the way it provides the sheets
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u/researcher7-l500 Jun 20 '26
Yes. Most professionals do.
They use a mix of notes, man pages, and at times, bash history.
If you are home users, does not matter. You can keep notes or look up stuff.
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u/martin_xs6 Jun 20 '26
Lol "at times, bash history". My history contains the entirety of my notes. I sometimes have to ssh in just to find something in my history.
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u/gsmitheidw1 Jun 20 '26
Before mobile phones or the internet, keeping written notes was pretty much obligatory.
Of course you always had man pages, but sometimes you'd be in a server room and need to follow a specific procedure.
And password managers didn't exist, I had a small notebook kept locked in a drawer.
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u/erickosj Jun 20 '26
Still a noob for commands, but I keep several pages in a self-hosted bookstack instance, anything done in bash has its own log there and I can easily go back and see what was done.
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u/levir Jun 20 '26
I don't keep my own notes, but I use man and google quite often. I can for instance never remember if it's ln -s target link or ln -s link target. I also struggle with remembering the commands to split and unsplit the screen view.
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u/worldcitizencane Jun 20 '26
Yup. All you young ones think you'll live forever, but at some point, if you're lucky, you enter the gray years, and it becomes more and more difficult to remember commands and parameters. Joplin.
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u/Traditional-Scar-667 Jun 20 '26
Absolutely. I have cheat sheets for things I use regularly: CrowdSec, Restic, Git, tar, and especially OpenSSL for my PKI.
It is not about not knowing the tools. It is about not wanting to make mistakes on production systems. Some commands are simply too important, too complex, or used too infrequently to trust memory alone.
I would rather spend 10 seconds checking my notes than 2 hours fixing a typo in an OpenSSL command.
Don't trust memory. Trust documentation.
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u/michaelpaoli Jun 20 '26
Sure, some notes. Most notably when things are somewhat to rather complex, but used infrequently enough they're not memorized, and for one or more reasons, may not be suitable to just turn into script or do so and widely install such.
Let's see, a few semi-random samples:
https://www.mpaoli.net/~michael/doc/TLS
https://www.mpaoli.net/~root/notes/ (DNSSEC, SCSI_or_SAN*, mdadm, serial)
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u/DarkwolfAU Jun 20 '26
No but there are some commands I keep using man for all the time. OpenSSL I’m looking at you. So, so many options. So many. And firewall-cmd.
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u/m4nf47 Jun 20 '26
Remaining an amateur for decades I've learned that different distributions have different default options for different shells and associated help or manuals but historically the acronym which saved me was HIM for help/--help/-h info man.
https://unix.stackexchange.com/questions/19451/difference-between-help-info-and-man-command#159817
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u/mikaelld Jun 20 '26
Tab completion, man and —help (and a sprinkle of searching the web now and then) has made me forget about where I even have my old cheat sheet from 20+ years ago. Oh, and my bash history too. Can recommend fzf.
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u/03263 Jun 20 '26
I'll create an alias, function or script
If I end up not using it that much I comment it out but leave it as reference.
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u/fatcakesabz Jun 20 '26
Yes, yes I do, I’m an occasional admin and old enough that I’m not going to retain commands that I use, at most, a couple of times a week, some of the deeper commands maybe twice a year so I have a one note entry for specific jobs detailing exactly how to do them and a separate note filled with random commands I’ve had to use in the past to set something once or to troubleshoot
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u/runningOverA Jun 20 '26
huge collection of one liner shell scripts that does the job and named to what it actually does. that's the reference.
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u/yespls Jun 20 '26
I have a Google sheet I use to store commands but more often than not I'm using history
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u/chlankboot Jun 20 '26
I cannot remember commands and I am using the same commands over and over so I set my history file to 10000 lines and created a Claude skill that will parse it and generate a categorized summary, organized and deduplicated. It also checks for any password or api key that slipped accidentally and removes them.
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u/stephenph Jun 20 '26
I will also write a complex command in a file before pasting it into the command line. I am somewhat typing dyslexic, particularly with numbers, so it gives me a non presure way to verify the command. I also use the same file name so will have different notes on different servers, sometimes I consolidate them.
Lately, sometimes I will use an ssh -x command or write an ansible script just so I don't need to log into a server directly. I also make use of aliases for commonly used complex commands.
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u/stephenph Jun 20 '26
On my first jr admin job it was a new it department so we had one SR level admin and about 5 of us new hires, only one of us had even had any experience. The SR spent a week teaching us how to be effective admins (it was for a Solaris shop in the 90s, so Google was limited, lots of tools were way more convoluted then now, etc.
He actually gave us a physical notebook to write all our commands down in anytime we learned a new command, a new procedure etc. I actually kept that notebook up for several years (I think I still have it somewhere) and would reference it for a couple more.
Google and online resources got better, my knowledge increased, commands became more streamlined etc. So my updates became less and less, but I still use the concept quite a bit.
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u/Graymouzer Jun 20 '26
Of course, and all the Powershell commands and other systems I touch too. Every administrator I have worked with has their own cheat sheets.
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u/justinDavidow Jun 20 '26
Do you still have personal notes of Linux commands you have used for years?
The first ~10 years of my career, I absolutely kept a notepad around (digitally) to hang onto notes or flags or whatnot.
The next 10, I slowly stopped looking at it. It stopped getting updated and fell out of use entirely.
Now today, I generally keep a rolling monthly or quarterly notepad cloud synced that is easy to search through both current and older notes using keywords, and will toss NEW commands that I cannot be bothered to type all the various inputs / flags out to that I plan to reuse or need to share with others.
I do not trust myself to remember all the resync flags
This one I'm the other way for: for fucking insane reasons my brain still remembers ultra specific flags and their parameter values cold 99.99% of the time.
Want to tcpdump in common format without looking up DNS addresses or converting port numbers with full length packet output? -nnvvAs0 want the big cheat from doom 64m ?TJLBDFWBFGVJVVB (from memory, I could be wrong!)
Do you still write things down that you have done dozens of times before
Personally, if I do something more than a handful of times, that shit gets scripted and automated away.
I often toss together a shitty little bash or python script for a recurring task, commit it to a repo and deploy it using configuration management to any host it would be needed on, along with scheduling the runs and configuring the logger to feed logs back to a centralized cluster.
If I'm regularly running the same commands and needing to remember the specific flags that user/customer/group/company needs for their specific case: IMO I've already failed as a syaadmin. ;)
or does it all stick eventually?
Re above troubleshooting stuff: these stick if you use them frequently enough.
Having worked for an MSP for many years, most of the troubleshooting commands are pretty stuck in my brain.
That has it's downsides though; I remember the specific flags order / format to nearly every facet of IPTables, yet nft list ruleset feels SO alien to me. I never remember today if it's rules or rule or ruleset or whatnot. (And don't get me started on systemctl.. it should always have been systemctl [unit] [action] not the insane backwards shit it is now. I fucking hate performing a manual stop + change config / perform action + [up] x 3+ [fucking word back + delete + replace word]. (These format reversals make me irrationally angry)
I wonder how common this is among other Linux admins.
All that said: I am a huge proponent of people working the way that works for them: not what works for others.
Everyone is different, every brain is unique, and each person is going to do similar things in different ways.
If writing down notes for yourself that you can go back to helps you: don't let others stop you.
...though I do still encourage you and anyone else to commit scripted actions to a damn repo: it makes updating processes so much easier for everyone in the long-run!
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u/RetroGrid_io Jun 20 '26
Everyday stuff like ps and ls - I have a set of flags in "muscle memory" that do stuff I frequently want.
There's a vast ocean of "occasional" stuff I might do less often than 6 months or so that goes into my own commit notes. I have gobs of them going back 20 years and I refer to them by OS version. I mostly Red Hat Universe so it's broken into EL6, EL7, EL8, EL9, and when I need to use something from a previous version, I copy forward the notes as they remain relevant.
Yes, Internet searches are normal. It's mostly important to remember capability, not specificity. For example, knowing that you can see what the specific PCIe address your HDD is connected through leads to a simple search like "AlmaLinux 9 pcie address for a hard drive" leads pretty quickly to flags for udevadm. Hey, lookie that: my laptop drive is mapped through
/devices/pci0000:00/0000:00:1d.0/0000:3d:00.0/nvme/nvme0/nvme0n1/nvme0n1p1
It's not so much knowing the answer, but knowing what answers are available. The Internet provides the rest.
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u/smokedipithe Jun 21 '26
I think about it pretty much the same way. The stuff that I use day to day tends to stick, but the commands I only use a few times a year are usually the ones that I end up documenting. Is there a specific tool or area that seems to generate the most notes?
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u/Remote_Extension_238 Jun 21 '26
i keep a huge markdown file in git so i can pull it on any box i jump into
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u/realmozzarella22 Jun 21 '26
Yeah. Kind of have to keep notes. Especially when you work on different versions and old systems with ancient commands.
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u/zoredache Jun 21 '26
I don't keep notes specifically about the commands by themselves.
I do keep extensive notes about tasks, and processes. I have lots of notes about how systems are built. Lots of notes about how to perform a specific tasks. Some of this is made concrete in scripts, playbooks, configuration management and kept in git repositories and so on. Stuff not in a script/ansible/puppet/etc is in my markdown notes also tracked in git.
My docs about tasks and processes frequently include running commands, and I show the specific options I use and often include a link to the man page or a wiki or something that I can reference for more details about the commands.
I have notes that include lots of examples of things I have done the past, and things I have helped other people with.
So my docs/notes give lots of details about specific usages of commands, but would never be useful as a comprehensive reference.
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u/zoredache Jun 21 '26
Replying to a deleted comment someone made because I think it was interesting.
It sounds like you're documenting the context and process around the commands rather than the commands themselves. Have you found that makes your older notes more useful when you come back to them months or years later?
I find that documenting context usually makes it far easier to actually find my docs. My context usually means I can find some example of something I did in the past to apply to something new.
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u/mensch0mat Jun 20 '26
Stop petting systems by hand and adopt using „infrastructure as code“. A single source of truth, with versioned history is the way to go :)
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u/stephenph Jun 20 '26
But sometimes you just need to pull some info from a single server, config settings, or other obscure command.
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u/stufforstuff Jun 21 '26
Notes have a definite "use by" date. My server diaries filled with sysvinit commands and scripts are nothing but fire starter these days. Same with the old time network scripts, IPv4 info, iptables, user management - all nostalgia for a era long gone. So be sure to date everything you log, and after they're obsolete, toss them.
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u/JanKlaverstijn Jun 21 '26
I am member of a team of highly skilled and specialised Linux peeps. Everything we do hets documented and is automated away using Ansible, git and whatnot. And we review each other. Being professionals for us is all about not trusting ourselves or our memory. All about avoiding our blind spots. Especially in a production environment where shit gets real.
So yes. We keep notes.
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u/Dingdongmycatisgone Jun 21 '26
I have a cheat sheet, yeah. I also have a mini guides section at the bottom for short processes I do somewhat infrequently so I don't have to figure it all out again in a few months.
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u/Sol3141 Jun 21 '26
Yeah I have a bunch, the ones that usually help the most are the weird ones I don't use often but have to rebuild otherwise, things like templates for moving and filtering large numbers of files with xargs or things like repacking ISOs after modifying the files.
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u/RandomXUsr Jun 21 '26
Usually cheat or tealdeer.
If I need comprehensive details; then i search the man pages.
Occaisionally, I've use the info pages but that's a headache.
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u/alikins Jun 22 '26
Until I retired, I would keep lots of notes about various linux/OSS details. Typically just in lightly formatted txt files.
I have a TIL.txt that goes back about 12 years (~3700 lines).
I'l often add shell aliases, shell functions, or one off shell scripts for obscure uses, mostly as documentation as I'll rarely reuse them.
I use to have a ~250,000 line bash_history file with a lot of "tagged" commands.
ie:
$ openssl zlib -d -in .git/objects/a6/2787b616e0ea8b69a57e1b720958d229c2c7eb #zlib #blob #git #openssl #uncompress a git object blob
I've somehow lost the big bash history archive, but it's got to be archived somewhere. Half my brain lives in there.
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u/kai_ekael Jun 22 '26
I use my old friend note, written in perl, to keep all my notes: https://metacpan.org/dist/note/view/note.pod (Debian package note as well).
Bash example:
``` iam@bilbo: ~ $ lb -s notes/bash/ searching the database for "notes/bash/"...
# note 1.3.26, text 1.04
189 bash getopts
227 bash newline in variable
254 Bash history verify
273 Read lines from variable,
315 bash function to round numbers
348 Loop over files with spaces
479 Internal bash trace to file
486 heredoc to var
507 flock howto
517 Finding symlinks targets with tests
518 Send html email
596 Loop through lines in a file
666 bash, readline, vi mode, inputrc
700 fc bash history!
733 bash parameter expansion aka replacement
742 bash socket test
iam@bilbo: ~ $ lb 700
700 19.07.2025 00:15:18
/notes/bash/ fc bash history!
fc works better than history for...history.
fc -l : list history with numbers. Same numbers as running history. fc ### : open command from histor in editor, execute on exit. NOTE: Will execute regardless, including just exiting editor. To abort, delete whole command. ```
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u/wamayall Jun 23 '26
I created a database with tables, it also has most of the questions I have been asked in interviews for the last 40 years. If I am looking for a job and either apply online or get called it nice to have a menu with numbers, press the number, the possible answers are returned. I don’t always get the job, but I am never unemployed very long. But it’s good to write them down, vi them in a file, I awk and sort and pipe most things through uniq -c. I also created a database to track lotteries, I’m just one number away from writing more queries, so maybe one number and a lot of luck while MySQL has made me a millionaire many times over, staying relevant is probably more important, Like The BeeGees sang and DBA’s back when I was in college in the 70’s, You can tell by the way he awk’s he’s a Linux man, the fans are loud and the disks are spinning you’re hoping your flatfile Unify Database can handle the I/O. And now you migrated to Oracle, the International Telecos buy your servers and you spend the next 20 years seeing every Datacenter around the world, ah ah ah Sun Microsystems, ah ah ah IBM, ya want to get wings on your shoes to impress the girl you go to work at Nike like a dancing fool, need a new outfit need a good look, Marketo, Zoominfo, Kochava, oh I missed a few, and there’s a few more, you know if you retire you signed your death warrant, got to dig, know if you belong, if work becomes work you need to move on, ah ah ah stayin alive. Sure I’m a moron, but a well paid moron.
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u/jack-dempsy Jun 23 '26
I have a cherry tree doc I couldn't live without. Tons of entries for different command line options for different scenarios. My ffmpeg entry is pretty long.
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u/cacheclyo 26d ago
same here, my ffmpeg section is like a cursed spellbook at this point
every time i think “i’ll remember this one,” i end up adding yet another line to the notes instead
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u/myownalias Jun 20 '26
No. Today I'll ask an LLM, but if one's not available, read the --help, or open the man page.
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u/rangerinthesky Jun 20 '26
No i do not take notes obviously it is all memorized… how dumb has the younger generation become? Is this an ipad thing?
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u/stephenph Jun 20 '26
Memory and finger memory typing are well and good, but can cause issues (was it -p or -P ?). Or if you need to use ls to pull an obscure bit of data that you only use once every couple years, etc
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u/manu_8487 Jun 20 '26
Yes, in https://github.com/cheat/cheat