sqlite3 cheat sheet

• .tables -> show tables
• .schema table_name -> describe table

PostgreSQL on Docker

Running Postgres on Docker is easy. Upgrading major versions is not. Some useful commands:

• Running psql docker exec -it postgrespostgres1 psql -U postgres databasename

• Dump everything in a gzipped file

• Upgrade major version

This is tricky. I use this:

docker run --rm -v /data/postgres:/var/lib/postgresql tianon/postgres-upgrade:14-to-15 --link

You need to have your data in the following stucture: /data/postgres/14/data (old version) /data/postgres/15/data (new version will be linked here)

VIM tips 5

• Use fchar or tchar to move to that char, press ";" to go next, press "," to go back.
• o creates a newline and changes to insert mode, O (capital o) creates a newline above your cursor and changes to insert mode.
• zz centers cursor position
• vi" selects everything between ". Works with ( or < as well.
• CTRL+o (older) or CRTL+i (newer) in normal mode moves between last opened files

VIM tips 4

• C deletes until the end of the line and turns on insert mode
• D deletes until the end of the line
• rx replaces the char under the cursor with x
• CTRL+n autocompletes stuff from any buffer (navigate with CTRL+n/CRTL+p)

Some "g" commands

• g; jumps to your last change (even after reopening)
• ga over a letter shows its ASCII code
• gd jumps to the corresponding definition
• gM jumps to the middle of the line
• gm jumps to the middle of the screen line
• gv reselects the previous visual area

Pacman

When I migrated from Ubuntu to Arch I had a hard time remembering Pacman's (the Arch package manager) commands. Here we go:

• pacman -Sy updates the package lists
• pacman -Su upgrades the system
• pacman -Syu updates and upgrades
• pacman -Ss searches for installable packages
• pacman -R removes a package
• pacman -Rs removes a package and its dependencies
• pacman -Qi shows info about an installed package
• pacman -Ql list all files of an installed package
• pacman -Qm show all installed AUR packages
• pacman -Qo /path/to/filename shows which package a file belongs to
• pacman -Qe lists all packages explicitly installed
• pacman -Qd lists all packages installed as a dependency for another package
• pacman -Qt searches for missed installed orphans / packages that not required by any other packages
• pacman -Fs searches for a file in installable packages
• pacman -Sc clears uninstalled packages from cache
• pacman -Scc clears all cached packages
• pacman -U file:///var/cache/pacman/pkg/package.zst downgrades a package from cache

Consider using yay as a frontend for pacman. Really convernient + fast. Plus you can manage AUR packages with it as well.

Update 2019: Nah.

I use the following aliases/bash functions in .bashrc:

alias upd='sudo pacman -Syu'

alias ins='sudo pacman -Sy'

alias aursearch='curl -s https://aur.archlinux.org/packages.gz
| zgrep'

aurinst () { pushd /home/psic4t/sys/aur &&
git clone https://aur.archlinux.org/"$1".git &&
cd "$1" && makepkg -si && popd; }

GIT for dummys

I use git only occasionally. Here are some basic commands to remember:

• git init # new repo
• git add *.go # add some files
• git commit -a -m "First commit" # make a commit
• git status # check for uncommitted changes
• git log # show commits, "--all" for all
• git diff # shows changes
• git checkout # checkout different commit
• git master # back to master
• git remote add origin git@git.sr.ht:~psic4t/bla # setup remote repo
• git push -u origin master # push to remote repo
• git tag -a "0.8.4" # tag release
• git push origin "0.8.4" # push tag to remote repo
• git clone git@github.com:mygitname/theproject.git --branch 1.0.2 # clone specific release
• git commit --amend # change last commit message
• git revert HEAD # revert last commit but keep that commit in history

vim tips 3

Even more of this.

• c-o which will take you out of insert, letting you do one normal command, and then put you right back into insert.
• alt-keystroke changes to normal mode and executes keystroke
• ZQ is equivalent to :wq!
• mark some text and press ~ to switch case
• ci" removes everything between " in line and changes to insert mode
• :digraphs prints a list of key combos for characters like ©
• c-a increments number under cursor, c-x decrements number under cursor
• c-d removes indentation level in insert mode and c-t adds indentation level in insert mode
• type (partial) word. type c-x c-p for word completion. use c-n or c-p to chose the right one