linux tools commands.txt

fc-list -> to see all the installed fonts on the system 

yay -Yc -> to remove the unneeded dependencies with help of yay

chsh -s $(which zsh)  -> to change the default shell to zsh (restart after executing this)
unrar x file_name.rar -> to open the rar file
dirname "file_name" -> gives path of file, but if we are in same dir then it gives a dot (.)

redshift -> a program to use to have night light

ls /var/cache/pacman/pkg/ -> this is list of installed programs and also their previous versions

## for runit
sudo poweroff - to shutdown
sudo reboot - to restart

ps --no-headers -o comm 1 -> prints the init system we are using

'xdg-mime default org.pwmt.zathura.desktop application/pdf' -> run this to make zathura default pdf viewer

## accessing webcam 
mpv /dev/video0 -> the webcam is a file named video0 so just use mpv to play it

## general terminal stuff
echo "hello" > some.txt - this puts 'hello' in some.txt file, if something is previously present then it is deleted
echo "hello" >> some.txt - this puts 'hello' in some.txt file, but doesn't delete the previous stuff
echo $$ - this prints the pid of the current terminal
cp {fil1,file2,file3} /path/to/copy/ -> copies mutilple files to a dirname

sudo chown -R omkar [file or dir] -> to change owner of files or dir to user name (-R is for recurvsively)

link existing_file /path/to/create/new_file -> the link command creates new physical file and links the existing file with it
symbolic link :
   1st go to directory in which you want to create a symbolic link file
   'ln -s file_to_be_linked new_file' -> this will create a new file in current dir which will point to an existing file from another dir
(remember for sym link - if any 1 file is changed, the other file is also changed)

Automating stuff with entr -> https://youtu.be/9KAp_zWeI34     (http://eradman.com/entrproject/)

sudo ntpd -qg -> it sets the correct system time in runit sys
sudo hwclock -w -> it sets hardware clock time with system clock time (use only when bios ie hw time is wrong)

install 'webp-pixbuf-loader' package for viewing webp images in ristretto (default xfce image viewer)

---------- makepkg ------------------------------------------
makepkg -sirc
-s –> installs any missing dependencies using the package manager
-i –> installs the package after it has been built
-r –>removes any dependencies required by the build process that aren’t required afterwards
-c –> cleans up any leftover work files or directories created during the build process

---------- To see if we are using x11 or wayland ------------
'loginctl' -> first run this and note the session_id
'loginctl show-session <session_id> -p Type' -> this will output something like this - Type=x11

-------------- Fix Your Hipster Distro ----------------------------------
1. a program depends on some shared library of another program, when we upgrade our system and if that program is looking for older version of that shared lib, then we can downgrade that lib's program with -
      'sudo pacman -U /var/cache/pacman/pkg/<specific_tar_file_of_prgram_to_downgrade_to>'
2. but again running pacman with -Syy it will upgrade that package, so to persist the downgrade, edit the /etc/pacman.conf file and look for 'IgnorePkg' line and add the name of downgraded package there
3. but downgrading is not always good, and such problems mainly occur with AUR packages
so easy solution is to recompile them using -
   'yay -S <package_name>' (remember to press 'A' for clean build)