Linux life

Last edited 2022-11-24

Without Linux, computing and especially WEB would evolve in different way and most likely would be less affordable. Summary of commands/approaches, I use frequently. WIP.

Helpful commands

history - history

Becomes really useful paired with grep, that allow to narrow history output results. Whenever I remember only a part of command, that I have used (copy-pasted form internet, cause this is what You do in Linux, find commands You barely understand and run with sudo privileges), just add the remembered part after grep:

> history | grep tail
  638  [10/10 21:02:43] history | grep tail
  639  [10/10 21:02:46] history | grep tails
  640  [10/10 21:03:29] dpkg -l | tail -n +6 | grep -E 'linux-image-[0-9]+'

Now in order to use the command, hit !640 - it will execute the command with number 640.

> !640
rc  linux-image-5.11.0-27-generic  5.11.0-27.29~20.04.1  amd64  Signed kernel image generic
rc  linux-image-5.11.0-40-generic  5.11.0-40.44~20.04.2  amd64  Signed kernel image generic
rc  linux-image-5.11.0-43-generic  5.11.0-43.47~20.04.2  amd64  Signed kernel image generic
rc  linux-image-5.13.0-28-generic  5.13.0-28.31~20.04.1  amd64  Signed kernel image generic
ii  linux-image-5.15.0-50-generic  5.15.0-50.56~20.04.1  amd64  Signed kernel image generic

When need to edit command before use, add :p:

> !640:p 
dpkg -l | tail -n +6 | grep -E 'linux-image-[0-9]+'

Now it will become the last entered command, so can hit UP or fc arrow to edit it.

dpkg --purge Purging old kernels.

Sometimes You can’t sudo apt-get upgrade anymore it gives some error. Especially when disk is encrypted, boot partition tends to be smallish. So just check df /boot/:

> df /boot/
Filesystem     Type  Size  Used Avail Use% Mounted on
/dev/nvme0n1p2 ext4  704M  308M  345M  48% /boot

Use% should be small, found no better explanation than here: Official doc What I use from guide:

dpkg -l | tail -n +6 | grep -E 'linux-image-[0-9]+'
sudo update-initramfs -d -k old-kernel-name
sudo dpkg --purge old-kernel-name

fc - open last command in editor

Making typos in commands is annoying.

sudo apt-gEt update && sudo apt upgrade && sudo apt autoremove`
sudo: apt-gEt: command not found

Instead of hitting UP key, and key navigate to typo, fc would bring in last command inside VIM, edit, and :wq.

VIM- Setting as default editor

Using fc command makes only when VIM is Your editor.

echo "export EDITOR='vim'" >> ~/.bashrc

- or -- In your bash commands

- - single letter parameters, even when You pass many together. ls -alt parameters here will be treated as a, l, t.
-- - named parameters. apt-get autoremove --purge - paramter will be treated as purge

VIM getting through the day

Why? No need to ever touch mouse, in combination with Tmux becomes a super power. Using daily as main code-editor for typescript. Mostly using only basic commands. Enjoy the pattern: action + in or around + symbol.

• c + i + { - change text in curly braces.
• y + i + [ - copy text in rectangular braces.
• d + i + ( - delete text in usual braces.
• v + a + { - visually select all around curly braces.(gv to select same again)

And same pattern modified: action + on what exactly.

• c + 3w - change 3 words
• d + 7l - change 7 letters

Whole line actions (regardless of curor position in line):

• dd - delete whole line
• cc - change whole line
• yy - copy whole line

Navigation inside the text:

• gg - move to top of file
• G - move to bottom

Navigation between files(buffers):

• ctrl + o go to previous buffer
• ctrl + i got to next buffer

Going into insert mode for code is usually:

• Shift + o - above current line
• o - below current line

Copy using system clipboard (from Vim to any other program):

• " + * + ‘y’ - copies visually select text to clipboard

Aside from basic moves (j, k) that is enough to get Me trough the day. Vim is a rabbit whole in a way. There are multiple to do an operation. Generally less keystrokes approach should win.

Full configuration includes plugins also. Would emphasize NerdTREE as an absolute must have, as it gives project tree view on the left, with easy file operations context menu.

There are 12 more plugins in my config, they should be doing syntax highlighting, auto completion and fuzzy search. Not really needed to get started.

Adding Neovim to Ubuntu.

Official guide covers it all: https://github.com/neovim/neovim/wiki/Building-Neovim Now need to make it to actually launch neovim, when You type vim in terminal emulator(no rational justification to do it, just type nvim). update-alternatives command comes to help

> sudo update-alternatives --config vim
There are 2 choices for the alternative vim (providing /usr/bin/vim).

  Selection    Path                 Priority   Status
------------------------------------------------------------
* 0            /usr/local/bin/nvim   100       auto mode
  1            /usr/bin/vim.basic    30        manual mode
  2            /usr/local/bin/nvim   100       manual mode

Press <enter> to keep the current choice[*], or type selection number:

Sometimes after pulling latest changes, build breaks, most of the times need to purge old stuff with sudo make distclean.

Tmux

Whereas different terminal emulators might do have different shortcuts to splitting the screen, or adding a tab, tmux being an app running inside any terminal emulator, allows to remember those key-combos once. (no mouse again)
Great cheat sheet found here: https://tmuxcheatsheet.com/ An experience changer -> rebinding ctrl + b to ctrl + a. My config.
Great supplement to VIM.