Command Line Magic

Cool Unix/Linux Command Line tricks you can use. Here mostly to inspire all to try more. Read docs first, run later.

Public Key

npub17hcswhel45t4tnh3a7gzf4f74lfyafrq8qe3nlaejj0nk63umcdqcxtk0h

NIP-05 Address

climagic_at_mastodon.social@mostr.pub

Profile Code

nprofile1qqs0tug8tul66964emc7lypy65l2l5jw53srsvcel7uef8emdg7duxszx64qa

Author Public Key

npub17hcswhel45t4tnh3a7gzf4f74lfyafrq8qe3nlaejj0nk63umcdqcxtk0h

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Last Notes

2024-09-11 22:50:14

The new CLImagic stickers are available here:
https://www.ebay.com/itm/226344815489
and here:
https://www.ebay.com/itm/226345946412
Get them while they last.
https://files.mastodon.social/media_attachments/files/113/121/361/396/772/431/original/35a3c35ee7ad07d8.jpg

2024-09-11 18:35:01

We're coming up on Day 20,000 of Unix epoch time, which will be midnight GMT on Friday October 4th. Every 5000 days represents about 13 years, so these don't happen often.
date -d @$(( 86400 * 20000 ))

2024-08-31 15:05:56

In case you haven't seen it yet, the NSA just a few days ago released a 42 year old lecture given in secret by the amazing Grace Hopper. https://www.nsa.gov/Press-Room/Press-Releases-Statements/Press-Release-View/Article/3884041/nsa-releases-copy-of-internal-lecture-delivered-by-computing-giant-rear-adm-gra/

2024-08-29 12:37:57

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@npub1q2z…fyk3 Very nice

2024-08-26 19:20:52

Make your Monday brighter with some colorful gradients in your terminal.
yes "$(seq 231 -1 16)" | while read i; do printf "\x1b[48;5;${i}m\n"; sleep .02; done
https://files.mastodon.social/media_attachments/files/113/029/886/349/962/530/original/5b3d5fa3bf675ffe.mp4

2024-08-26 00:03:18

The legendary Herobrine tried to connect to my Minecraft server. As seen on a VT420 terminal. You'll be able to see this VT420 terminal at VCFMW 19 in Chicago on Sept 7th. https://www.vcfmw.org/
https://files.mastodon.social/media_attachments/files/113/025/384/452/740/088/original/85e5e0b04610b597.jpg

2024-08-23 22:18:05

What did the ancient Greeks call their computers?
BCs

2024-08-19 18:50:26

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@npub1ajl…570w It might complain that the database is locked if you don't.

2024-08-19 15:37:23

Firefox users can make SQL queries against their history database using sqlite3. Just shut down Firefox first. This will find top level URLs you've visited.
sqlite3 places.sqlite "SELECT url FROM moz_places WHERE substr(url,-1,1)=='/' AND length(url)-length(replace(url,'/',''))<4;"

2024-08-14 23:57:07

People are still buying Ubuntu
https://files.mastodon.social/media_attachments/files/112/963/074/951/912/839/original/69a249a67797685d.gif

2024-08-01 13:04:04

When you shutdown/reboot your system from the command line in bash, the active session command history is lost, to preserve it by appending (-a) it to .bash_history run:
history -a
before running shutdown.

2024-07-30 14:50:13

Your excuse: The host is so secure, even you can't get in.

2024-07-26 15:27:45

If you ever need to test keys on your keyboard in X windows, a nice program to use is xev. You can run it like this from the shell:
xev -event keyboard
Then make sure its window has focus and start pressing keys. To stop, close the window.
https://files.mastodon.social/media_attachments/files/112/853/488/009/689/465/original/8c8c03d993b30af9.jpg

2024-07-19 17:44:18

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@npub15f2…5ync For next time

2024-07-19 17:43:39

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@npub1hq5…7uup Well they're paying for that efficiency right now.

2024-07-19 17:35:54

Wait one more one more.
https://www.youtube.com/watch?v=VIRkqIoE0jg

2024-07-19 17:16:18

Please tell me again why we should all be using the same operating system everywhere. And while we're at it, centralized DNS services.
https://files.mastodon.social/media_attachments/files/112/814/277/101/212/301/original/06dcf5bf74c8e3e6.jpg

2024-07-17 17:27:03

What do you call a flower that always faces away from the sun?
A Shunflower

2024-07-14 22:40:19

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@npub1fru…epau Not quite I'm afraid. He used a ADM-3A terminal. If you look at that terminals keyboard layout you'll see why.

2024-07-14 22:15:49

Anyone happen to have some spare DEC VT100 key caps? Looks like I'm missing a "No scroll" and a "right arrow key". :D
https://files.mastodon.social/media_attachments/files/112/787/147/750/158/663/original/2ed0987b3cc71cc9.jpg

2024-06-28 00:33:36

Ticketmaster, the same company that told me my password must be between 1 and 255 characters.

2024-06-19 20:02:39

When I do this people call me a nerd.
https://files.mastodon.social/media_attachments/files/112/645/069/042/484/494/original/331dcedf299a4d02.png

2024-06-13 19:53:41

The downside to everyone implementing MFA is that the bad actors will just find other ways in. It's not like once we all turn on two factor that they just say "Oh darn, I better go find an honest job now".

2024-05-15 18:44:07

What is your LEAST favorite command?

2024-04-28 00:38:56

"You're stupid, why don't you just use the GUI file manager?"
[GUI file manager]:
https://files.mastodon.social/media_attachments/files/112/346/050/561/718/158/original/6393646662b42dc5.png

2024-04-27 23:40:48

Blast from the Turbo Linus
https://www.youtube.com/watch?v=EMtbRd7DPYU

2024-04-18 01:26:59

Is there a goddess of RAID controllers I can pray to?

2024-04-03 13:54:24

PSA: Don't make the mistake of missing eclipse totality once in your life just because you're worried about some traffic. Trust me when I say it's worth it (saw it in 2017). GET YOUR ASS TO THE TOTALITY ZONE ON APRIL 8TH.
https://www.youtube.com/watch?v=oZSJy_okRiI

2024-02-29 03:10:01

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@npub1lrl…j4fg you are a brave soul.

2024-02-29 03:07:51

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You might say it saved my assterisk.

2024-02-29 03:03:11

I created a file literally called -? In my homedir to help stop wildcard accidents with rm and mv and stray *s

2024-02-05 01:55:04

Those posts about Netiquette and FAQs stopped too soon. We really need them again.

2024-02-04 00:36:49

chfn
https://files.mastodon.social/media_attachments/files/111/870/387/169/960/888/original/69f0521f8b2a7c37.jpeg

2024-02-01 15:10:44

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@npub1t93…jpqq Yes thanks. This is better as it uses far less CPU.

2024-02-01 14:45:22

Sometimes you just want to play the audio from a video, such as one that has music in it:
mpv --vo=null musicvideo.mp4

2024-02-01 14:43:28

Sometimes you just want to play the audio from a video, such as one that has music in it:
mpv -vo null musicvideo.mp4

2024-01-24 12:40:18

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I guess another question along these lines is, did you ever have to follow up on someone who was abusing the system and was the email address helpful or did the abusers just use fake email addresses?

2024-01-24 12:35:21

Did any of you run an anonymous FTP server back in the mid 90s or earlier? Like at one of the big universities that had major FTP servers. Did putting your email address as your password actually get recorded somewhere? AFAIK the password was not logged in cleartext, so looking back, it seems pointless to have asked for that as if it was some form of ID.

2024-01-16 18:59:17

It's tough to read long numbers, especially the ones we see in data sizes these days. What can help is to use the -h option that is provided by some of the GNU utilities. For instance, long list files with human readable sizes:
ls -lh
Show filesystem data with human readable sizes:
df -h
Summarize disk use of directories:
du -sh */
Sort that output by the human readable sizes:
du -sh */ | sort -h

2024-01-16 18:58:40

It's tough to read long numbers, especially the ones we see in data sizes these days. What can help is to use the -h option that is provided by some of the GNU utilities. For instance, long list files with human readable sizes:
ls -lh
Show filesystem data with human readable sizes:
df -h
Summarize disk use of directories:
du -sh
Sort that output by the human readable sizes:
du -sh | sort -h

2024-01-16 14:34:30

"But look, you found the notice, didn’t you?"
"Yes," said Arthur, "yes I did. It was on display in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying 'Beware of the Leopard." -- Douglas Adams HHGTTG

2024-01-07 20:03:37

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@npub15yv…v3p4 Cool, thanks for sharing.

2024-01-07 19:11:12

Having read errors when using 'dd' to copy a disk/flash drive? You can try the 'ddrescue' program instead. It will retrieve the valid blocks first get most of your data back. Retrying the bad ones. Then you can use a program like 'photorec' to try to recover data from the image.

2024-01-07 18:29:01

The picture of the teletype is from https://www.electroprops.co.uk/
https://files.mastodon.social/media_attachments/files/111/716/077/821/884/964/original/43b922950211a939.gif

2023-11-29 14:57:11

If you have a large XML file that is all on one line and you need to make minor changes to it, many popular and even robust editors will choke on the line length, even with syntax highlighting turned off. One solution is to use a binary/hex editor like 'bvi':
bvi data.xml

2023-11-29 02:50:20

Ya know, it was one thing when binary bytes vs decimal bytes was a difference of like 1% of the drive, but now the difference is nearly one whole terabyte (sorry, tebibyte) and 9% difference. Now get off my lawnmower man.
https://files.mastodon.social/media_attachments/files/111/491/544/192/092/259/original/1b69b9cf82045ccc.png

2023-11-27 13:58:34

The new Amazon style looks like the classic Slashdot style and it's freaking me out.
https://files.mastodon.social/media_attachments/files/111/482/863/966/446/170/original/7ebf532969be8569.jpg
https://files.mastodon.social/media_attachments/files/111/482/864/450/984/427/original/9e59b8e5bb740288.jpg

2023-11-09 02:01:06

Tron 3 confirmed
https://files.mastodon.social/media_attachments/files/111/378/116/497/711/996/original/ff6f457379db5cff.png

2023-11-08 17:43:04

Use ip's stats (-s) and json output (-j) options with the jq command to parse the received byte count on your wireguard wg0 interface:
ip -s -j addr show dev wg0 | jq '.[].stats64.rx.bytes'

2023-11-08 17:32:43

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@npub1s3u…emev @npub1h2t…et5m Or just:
First bourne shell

2023-11-07 13:41:29

Take time to try new things, but keep time for the people that matter in your life.

2023-10-31 16:52:28

The climagic Halloween video was released 10 years ago today: https://www.youtube.com/watch?v=zRF1S-8P6_k

2023-10-21 15:13:56

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@npub1xww…xw20 One some installers, when setting up an encrypted partition they will ask if you want to fill the layer on top of the encryption with zeros or something so that the underlying layer looks like encryption all across the partition or disk. This makes it harder for an analyst to detect usage patterns.

2023-10-21 13:16:18

If you find yourself in a rush and don't want to wait for filling out an encrypted partition at install time (to hide disk usage patterns), you don't have to wait inside the installer. You can finish the install without doing that, reboot and do it from within the installed OS within the install with something like this:
ionice -n 3 dd if=/dev/zero of=bigfatzero bs=1M status=progress ; rm bigfatzero
The ionice will give the process lower i/o priority to keep your system snappy.

2023-10-21 02:14:36

Have multiple computers in front of you? If you didn't know about it, there is a program for Linux called Barrier (which is an open source alternative Synergy) for sharing a keyboard/mouse between multiple computers. It allows you to use the same mouse/keyboard across multiple computer's screens like it was all one desktop.

2023-10-12 15:00:32

People at work through the decades.
https://files.mastodon.social/media_attachments/files/111/222/627/622/562/994/original/f53cf2e652d156ab.jpg

2023-10-07 01:21:59

I've always read that global variables are bad.
https://files.mastodon.social/media_attachments/files/111/191/103/610/752/851/original/1b76e4f832ac6475.jpg

2023-09-27 00:06:23

We must have passed some kind of threshold because I just spent 30 minutes looking through my house for a micro USB cable and could only find USB-C cables.

2023-09-14 13:12:15

This past weekend I tried out Patrick Finnegan's Dot Matrix Printer Selfie System at VCF Midwest 18. Here is the video. https://www.youtube.com/watch?v=hSPG8nB6GtY

2023-09-14 12:21:24

I've seen things you people wouldn't believe. A log file that grew to 2.5GB in just five minutes. I've seen system loads of over 15,000. All these moments will be lost in time, like bits in DRAM. Time to reboot.
https://files.mastodon.social/media_attachments/files/111/063/463/046/288/260/original/2214e6ce83636dcd.jpeg

2023-09-09 14:59:58

Ready for "What's in a terminal?" With Richard Thomson at #vcfmw #vcfmidwest #vcf18

2023-09-05 13:29:47

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@npub1cly…6k3x It's the climagic logo made up of a montage of Unix commands. Here is a closer view.
https://files.mastodon.social/media_attachments/files/111/012/779/477/157/700/original/05da446aad851520.jpg

2023-09-05 13:09:41

This weekend I'm planning to attend the Midwest Vintage Computing Festival in Elmhurst, Illinois (Chicago). If you'll be there too it would be cool to meet up. So say hi if you see me wearing the climagic logo shirt. Or if someone else is wearing one, you should say hi to them too. ;) #vcfmidwest https://www.vcfmw.org/
https://files.mastodon.social/media_attachments/files/111/012/674/102/416/401/original/78eaeec6a4c1640f.jpg

2023-08-23 01:42:55

I recently have had to stress test a faulty motherboard/CPU and while I know there are programs like 'stress' out there, I found that "hexdump /dev/sda" over an ssh session was quite effective and quick. Turns out the thermal paste on this old combo had dried up.

2023-06-15 12:27:57

Debian 12 release notes:
[A syslog daemon is no longer installed by default]
https://files.mastodon.social/media_attachments/files/110/548/224/514/988/738/original/148262ef9c435c46.mp4

2023-06-12 13:55:36

Understanding Linux's new Network Interface "Predictable" Naming
https://files.mastodon.social/media_attachments/files/110/531/582/379/324/134/original/4adf66c5eccda89b.mp4

2023-06-12 00:17:10

Watch out, I just started up a server that hasn't been booted since 2015. It just found out about everything that's happened.

2023-06-01 17:17:33

I think this command (not mine) is just so elegant. It's for generating both the private key and the public key for a Wireguard tunnel in one go.
wg genkey | tee privatekey | wg pubkey > publickey

2023-05-02 13:59:47

With yt-dlp, it's essential to know about the -F and -f options to control the format and size of the video that you download. Use -F first to get a list of formats, maybe combine that with | grep -v "video only" to exclude those, then use -f with the format number. Otherwise you could waste a lot of space and bandwidth when you don't mean to.
yt-dlp -F id | grep -v "video only"
yt-dlp -f 22 id
https://files.mastodon.social/media_attachments/files/110/299/440/535/466/962/original/3146a34d4d4e55ae.jpg

2019-02-03 22:03:57

https://www.youtube.com/watch?v=n4Ul_A0VBVI # CLIMagic video: Years before the big players in streaming figured out how cord cutters could easily watch a sporting event live (they've figure it out now, right?), I used netcat to watch Superbowl 46. Here's a video demo/explanation.