Notices by Yes, I Know IT ! 🎓 (yesiknowit@mastodon.social), page 13

Fine tune Linux Kernel I/O by setting up dirty page parameters.

https://lonesysadmin.net/2013/12/22/better-linux-disk-caching-performance-vm-dirty_ratio/

#Linux #Kernel #Cache #Disk #Tuning

#OpenStack is a complex and somewhat frightening beast
https://opensource.com/resources/what-is-openstack

The history of Solaris and the free alternatives
https://www.yesik.it/SOLARIS2017

#Solaris #OpenSolaris #Illumos
#YesIKnowIT

JSON command line processing:
https://stedolan.github.io/jq/

(never ever use #sed for that!)
#JSON #CLI

So, you don't know yet the `grep` command ?
https://youtu.be/HBNNO92Juw4

#Shell #Linux #Grep
#YesIKnowIT

Print even lines
seq 10 | sed -n '1b;P;N'

#Shell #Sed #Linux

In #Bash, to edit the last three commands in your favorite EDITOR type:

fc -3 0

When leaving the editor, commands are executed

`less -R` will handle gracefully ANSI "color" escape sequences:
ls --color=always /tmp | less -R

#Linux #Shell #ls

Display all user accounts separated by a colon in one very long line

cut -d: -f1 /etc/passwd | paste -s -d:

#Paste #Cut #Linux #Unix #POSIX #Utility

In the Bash, `~-` is expanded to the content of `OLDPWD`. So:

cd ~-/..

is a shortcut for the 2 commands:

cd "$OLDPWD" (or `cd -`)
cd ..

#Bash #Shell

Merging files on a line-by-line basis with the `paste` utility
https://yesik.it/EP23

#Paste #POSIX #Utility #Linux #Unix #Shell

Find words starting with `lin` (according to `/usr/share/dict/words`):

```
look lin
```

#Linux #Look #Utility

Poor's (wo)man stopwatch in your shell:

```
time read
```

#Linux #Shell #Stopwatch

How to use the `chattr` command to secure shared files. An interesting post by Himanshu Arora on HowtoForge.
https://www.howtoforge.com/linux-chattr-command/

BTW, `chattr` has not to be confused with `chmod`!

#Chattr #Linux #Utility

Display a 2x3 matrix:

seq 6 | paste - - -

#Paste #Shell #Linux #Unix #POSIX #Utility

vlc -Idummy -Vcaca "Star Wars: Episode IV - A New Hope (1977).mkv"

Play #StarWars as it was originally intended by @GeorgeLucasILM back in the 70s

#VLC #AsciiArt #Linux #CommandLine

Split a fixed-width or delimited text file into individual columns using the `cut` command
https://yesik.it/EP22

#Cut #POSIX #Utility #Linux #Unix #Shell

Excellent post by @benfrederickson showing the programming language popularity on @GitHub as of Jan, 2018
https://www.benfrederickson.com/ranking-programming-languages-by-github-users/

Do you think things have evolved since that post?

How to catenate files scattered through several sub-directories?
https://yesik.it/blog/2018-catenate-files-from-subdirectories

#Linux #Grep #Find #Globstar #Catenate #TextFiles

Of bits and bytes
https://yesik.it/blog/2018-bit-nibble-byte-and-word

#Bit #Nibble #Byte #Octet #Word #BinaryArithmetic #BooleanAlgebra #ComputerScience #ComputerHistory