My Cheatsheet

00-index.md

bash	tmux/byobu	git	iTerm2	Linux
neovim	PostgreSQL	python	zsh	docker

bash.md

bash

• ESC f - next word
• ESC b - previous word
• ^w - delete previous word
• ^u - delete to line start
• ^y - paste deleted
• ESC d - delete next word
• ESC t - swap words
• ESC r - restore line
• ESC # - comment out line
• ESC * - insert file names in CWD starting with
• ^x^e - invoke editor for the command
• ^_ - undo edit
• : "${VAR:=default}" - set variable if not already set
• redirection
  • >&2 echo error - echo to stderr
  • 2>&1 - combine stdout and stderr
  • > >(tee stdout.log) 2> >(tee stderr.log) - redirect stdout and stderr to different files

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docker.md

docker

• calculate volume sizes

  docker volume ls -q | \
    parallel 'echo $(docker run -i --rm -v {}:/docs alpine du -sh /docs) {}' | \
    sort -hr

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git.md

git

• git worktree add <branch> <dir - create another directory with a branch
• git restore <branchtag|sha> -- <file> - restore deleted file
• git log --graph --all - show graph with all branches
• git show development:my_file.txt - show file in another branch
• git whatchanged -p my_file.rb - See What Has Changed on a File Over Time
• git rev-list --all | xargs git grep -F '' - grep all branches
• remove all untracked and ignored files and empty directories

  git clean -fdX
  find . -type d -empty -delete

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iTerm2.md

iTerm2

• <Command> <Alt> <Mouse> - iTerm2 rectangular selection

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Linux.md

Linux

• find . -mindepth 1 -maxdepth 1 -type d -print0 | xargs -0 du -sh | sort -h - list sizes of all directories including ones with spaces
  • simpler version: du -hd1
• -iname - is like -name but case insesitive
• ping 0 - check if network is running on the localhost
• use /usr/bin/time -v instead of time to get more detaiiled process infrmation
• sort a file keeping header at the top:

  cat file | (read -r; printf "%s\n" "$REPLY"; sort)

• sudo lshw - list hardware
• pipe through pv to see the command progress
• findmnt to see mount points with details

Ubuntu

• fix for command-not-found on Ubuntu

  sudo apt install --reinstall command-not-found
  sudo chmod -R o+r /var/lib/command-not-found/

• remote logout console session gnome-session-quit --no-prompt
• adduser
• sudo usermod -a -G <group> <user>; newgrp <group> add user to a group and reload assignment
• xsel - copy/paste from/to clipboard

MacOS

• ⌘⇧G Commnad-Shift-G in file dialog - enter path

Finder

• ⌘⇧. Command-Shift-. - show hidden files

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neovim.md

neovim

• gg/G - go to file start/end
• 556G - go to line 556
• n/N - find next/previous
• :map - show keybindings
• reload file
  • :edit - current buffer
  • :checktime - all files
• :r file - insert text from file
• ^w - window operations followed with
  • w - next window
  • v/s - vertical/horisontal split
  • o - minimize other windows
  • +/- - increase/decrease vertical size
  • </> - increase/decrease horisontal size
  • x - swap current window with the next
  • m - zoom/unzoom curren window
  • q - cancel window split
  • w - make all windows same size
• :set scrollbind - sync scroll in windows
• ^v - start rectangular selection
• :let mapleader - detect <Leader> key
• ^r - redo
• find/replace
  • :%s/str/repl/gc - ask and replace
  • :%s/%Vstr/repl/g - search/replace within none-line selection
• :set nowrap - prevent line wrapping
• ^y/^e/^u/^d - scroll up/down/pg up/pg down
• gc, move - comment/uncomment, if does not work
  • comment block: in the 1st column ^v, select block, I # Esc
  • uncomment block: in the 1st column ^v, select block, d Esc
• "ayy/"Ayy - copy/append selection to register a
• zR/zM - open/close all folds
• zo/zc open/close current fold
• >/< indent/unindent block
• >>/<< indent/unindent line
• ^r" insert register into command buffer
• :so % - reload config while editing init.vim
• F4 - ctags sidebar (:TagbarToggle)
• F7 - run flake8
• r - replace single character
• % - jump to matching bracket
• delete d/change c/yank y
  • di" - delete within quotes or other chracters
  • da" - delete within quotes and delete quotes
  • dtc - delete until chracter 'c'
  • df - delete until next space or other chracter including it
  • dT - delete backward until space or other character
  • daw - delete the whole word with space
  • diw - delte the whole word without space
• quoting/unquoting
  • cs"' - change " to '
  • ds" - unquote "
  • ysiw" - quote word with "
• ^o/^i - jump to previos/next location (normal mode)
• fc/Fc - jump forward/back to character c
• gqip - wrap current line
• :noh - remove search highlight
• macro
  • qaq - start where 'a' is a regizter a-z
  • N@a - play macro in register 'a' 'N' number of times
• ^6 - switch to previous buffer
• * - search for the word under cursor
• marks
  • ma - mark position a
  • `a - jump to position a
  • 'a - jump to line of position a
  • `. - jump to last edit
• ^ - move to 1st none-space character of the string
• INSERT mode
  • ^r* - insert yanked text
  • ^o - perform a single command from NORMAL mode
• r! date - insert current timestamp
• gx - open browser on the current link
• bw - completely close the file
• :help - get help on a topic
  • ^] - follow the link
  • ^T - go back
  • ^o/^i - history forward/back
• :argdo/:bufdo/:windo/tabdo - run operation on multiple files
• ^l - redraw screen

git/fugitive

• [/]c - jump prev/next hunk
• ,hs - stage current hunk
• ,hu - unstage current hunk
• :G - start commit
• ca in status window on commit -- amend

NERDTree

• ma - create a file in the selected directory
• :syntax on - fix weird symbols in the file list

DrawIt

• ,di - start line drawing mode
• ,ds - stop line drawing
• <,>,^,v - arrows
• ^v, draw block
  • ,b - draw a box
  • ,l - create a box
  • ,f - flood with character (does not work)

dbext

• ,sdt - describe table
• ,se - execute selection or statement under cursor
• :DBCompleteTables - load table names for completion

Spellchecker & Thesaurus Query

• :setlocal spell spelllang=en_us - start spellcheck
• z= - spelling suggestions
• zg - add misspelled word to local dictionary
• ]s/[s - move to next/previous misspelled word
• ,cs - on the word for list of synonyms, etc.

LatexBox

• \lv - Latex view
• \lt - Latex TOC
• % - jump matching bracket
• ^X^O - complete

xml-plugin

• % - jump between '<' and '>'
• > - complete single line tag
• >> - complete multiline tag
• \x - surround selection with a tag
• \% - jump to tag start
• \d - delete surrounding tags
• \c/\u - comment/uncomment selection

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postgresqlpostgis.md

PostgreSQL/PostGIS

• fast count of rows estimate

  SELECT n.nspname, relname, reltuples::bigint AS estimate
  FROM pg_class c
        JOIN pg_namespace AS n ON c.relnamespace = n.oid
  WHERE relname = 'table_name';

• poor man's histogram:

  SELECT width_bucket(numeric_column, 1, 200, 20), count(*)
  FROM table GROUP BY 1 ORDER BY 1

• split_part('a:b', ':', 1) -> a
• concat_ws(':', 'a', 'b', ..) - join strings with seprator
• stop/kill query

  SELECT * FROM pg_stat_activity WHERE state = 'active';
  SELECT pg_cancel_backend(<pid of the process>)

• convenient view for background queries

  SELECT 
    now()-query_start as elapsed, 
    state, datname, pid, usename, 
    query, application_name, client_addr, 
    query_start, state_change, 
    wait_event_type, wait_event 
  FROM pg_stat_activity WHERE state = 'active';

• get database size

  SELECT
    pg_size_pretty(pg_database_size(current_database()))
      AS database_size;

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python.md

Python

• import ipdb; ipdb.set_trace() - drop into iPython
• create virtual environment - https://docs.python.org/3/library/venv.html

  python3 -m venv --upgrade-deps venv && \
  . ./venv/bin/activate

• install requirements

  pip install -r requirements.txt

• find all python environments in current directory and below

  fd -p -g '**/bin/activate'

• aList[::-1] - reverse a list
• create conda environment:

  conda create -n <env> python=3.12 pip 
  conda activate <env>

• useful decorators

  @atexit.register
  @dataclass
  @unique
  @singledispatch

• clickable terminal links

  import rich
  rich.print("Hello [link=http://localhost:8000]App[/link]!")

• slotted classes __slots__: 'slot'
• sys.getsizeof(mylist)

Pandas

• replace column names: df.columns = ['a', 'b', 'c']
• insert top row

  df.loc[-1] = [1,2,3]
  df.index = df.index + 1
  df = df.sort_index()

• drop empty rows: df.dropna(axis='rows', inplace=True, how='all')

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tmux.md

tmux

• ^B I - Installs new plugins from GitHub or any other git repository
• ^B U - updates plugin(s)
• ^B alt u- remove/uninstall plugins not on the plugin list
• ^B [ - scroll/copy mode
  • q - quits
  • ^<space> - start higlight
  • <esc>w - copy highlighted text
• ^B %/| - split vertical/horizontal
• ^B <-/^B -> - move between windows
• ^B z - zoom pane to the whole window
• ^B / - search
• ^B y - copy command to clipboard
• ^B Y - copy PWD to clipboard
• ^B C - create new session from within the currebt one
• ^B g - switch to another session
• ^B ] - paste from clipboard
• ^B b - last window
• ^B <space> - change layout
• save buffer in file: ^B:capture-pane -S -3000<enter>^B:save-buffer file.txt<enter>
• ^B D - disconnect other clients
• tmux new-session -A -s NAME - create new or attach to existing named session

byobu

• byobu-tmux - start byobu with tmux CLI options
• ^B |/% - horizontal/vertical split
• Enter - copy highlight

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zsh.md

zsh

• [tab] - file name globs (requires setopt extendedglob)
  • <200-300> - range of integers
  • ^*.c - negate glob
  • ~ - exclude from pattern
  • **/* - get into subdir
• =<command> - $(which <command>)
• fc - run the editor on previous command
• r a=b - rerun previous command with optional substitution
• [ESC]q - put command on stack
• [ESC]a - execute command keep it in buffer
• [ESC]' - escape command

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