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Monday, June 29, 2020

Some Latex and Linux commands

Latex 
\foreach \n in {0,...,2}{do something \newline}


Linux

Delete empty directories
find . -empty -type d -delete

find files and mention the size of each,
find Desktop/prova/ -iname "*.pdf" -exec du -hs {} \;

Find multiple files and remove them
find ~/Desktop/Junk/ -type f \( -iname "*.zip" -o -iname "*.jpeg" -o -iname "*.srt" \) -exec rm {} \;

count the files created in the last 1 min
find . -mmin -1 -type f -delete | wc -l

Delete all files created in the last 1 min
find . -mmin -1 -type f -delete

rsync is far better than cp
rsync -zaPv --delete --dry-run abc\ backup\
(dryrun gives the idea about what will be done without doing it
delete will keep the content same on both side
z compression and decompression
P progress
a arkiv
v used in conjunction with dryrun to see the output of what will be done without doing it)

Run periodic command with crontab
crontab -e
list commands to be run and time it has to be run and you are good to go. The following would write hello in helloooo.txt every min 24/7.
 * * * * * echo hello >> Desktop/helloooo.txt

select-editor - let you select one

The following might be good to look at to get more info,
https://crontab.guru/

List all software packages on Ubuntu Linux available for us 
apt list 

Use \textit{grep} to filter out 
dpkg --list | grep nginx 

Both installed and packages available to install 
apt list --installed 

How to list or find out if a specific package installed or not 
Eg. apt list -a okular 

If you wanna search the file, with string, heyboy, in the directory, /home/James/Downloads, do the following (-r and -i stands for search in folder and ignore character case resp.)
grep -r -i "heyboy" /home/James/Downloads

To find abc* in current directory 
find . -iname abc*

To find abc* in /Downloads/ directory 
find /Downloads/ -iname abc*

Find files (f) in current dir and then feed it to grep({}) to see if it contains text with 'abc', and consequently print it.
find . -type f -exec grep "abc" '{}'\; -print

or

find . -type f -print | xargs grep "abc"

Find and delete the files (BE CAREFUL)
find . -iname "abc" -delete

Join pdf files
pdftk 1.pdf 2.pdf  cat output nfile.pdf


To check if some package, say google chrome, is installed,
apt-cache policy google-chrome-stable

To count pdf in given folder,
count *.pdf

count number of lines in a.pdf 
wc -l a.pdf

count number of words in a.pdf 
wc -w a.pdf

Set up alarm using sleep command
sleep 15m && rhythmbox abc.mp3
'sleep' is used to perform some tasks after the time defined.  Example above, I want to play mp3 after 15 minutes.

cron command
https://github.com/CoreyMSchafer/code_snippets/blob/master/Cron-Tasks/snippets.txt

'apt show flowblade' would show me version to be installed and dependencies

sudo apt search paint - would show me all possible software with paint in its description

curl cheat.sh - an awesome thing to get man like description, but very brief, which is what you wished for many times you used man.

In case you wanna close the terminal and some process 36089 is running. So if you close the process might close. If you run the following command, you will not lose the process while closing the terminal 
disown 36089

Calibre is one of the best reader, install it
sudo apt install calibre

My favorite commands,
touch

less

man

htop

cat
cat abc - create file abc
cat >abc - prompt to write in abc
cat abc > t - would overwrite t with abc content
cat abc >> t - would append abc to at the end of t content
cat abc | less - shows abc and let you scroll file nicely

nano

Speed up UBUNTU

Change the DNS to Google DNS and speed up your internet,
8.8.8.8, 8.8.4.4 is google DNS. Cloudflare DNS is also a good option, I guess.

Install Ubuntu Restricted Extras (Media Codecs):
sudo apt install ubuntu-restricted-extras

Install Timeshift Backup Tool:
sudo apt install timeshift

Improve Laptop Battery:
sudo apt install tlp tlp-rdw

Firefox Tweaks: Make it work better, doing 
1. about:config -- accept

2. layers.acceleration.force-enabled -- set up true value

3. gfx.webrender.all -- set up true value

Every time security updates make you restart the laptop which pisses you off, here is the solution:
Just activate a livepatch and you are good to go.


If you were wondering about how to record the screen on Ubuntu 18.04, here is the answer. To me, Simplescreenrecorder is one of the best software to do so. To do so just run following command in your terminal

sudo add-apt-repository ppa:maarten-baert/simplescreenrecorder && sudo apt update && sudo apt install simplescreenrecorder


How do I see what packages are installed on Ubuntu Linux?

In case, you ever wondered about how to check if some software X is already installed on your Ubuntu, here is the tool to know,

A trip to Buzios, Arraial do Cabo and Cabo Frio - Brazil

What a wonderful trip it was I must say. Of course, there were some downs as well, as expected. We started off with Buzios.  If you ever pla...