justing.net/til

Git Branches

2022-12-03T00:00:00-08:00

Dealing with Git branches

Create a branch: git checkout -b <branch name>.

Push it upstream to remote: git push -u origin <branch name>.

If you’re working on multiple branche, keep them up to date with the main branch. First make sure local is up to date with remote with git update. Then on the feature branch, do git merge main.

When you’re ready to merge the feature into main, first catch it up to main as in the previous paragraph. Then git checkout main, and git merge <feature branch>.

Finally, to detele the feature branch if you are done with it, do git branch -d <feature branch> and git push origin --delete <feature branch>.

Last, check the list of branches with git branch -a.

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Ffmpeg Guide

2022-12-01T00:00:00-08:00

FFMPEG guide

Guide.

Grep With Context

2022-07-22T00:00:00-07:00

Grep and show context in file

grep "[search]" -A 5 -B 5 [file]

Ffmpeg Still To Video

2021-12-01T00:00:00-08:00

Make videos from a still image and audio file for youtube with `ffmpeg`

Get ffmpeg for mac here.

ffmpeg -loop 1 -i image.jpeg -i audio.wav -c:v libx264 \
   -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p \
   -shortest out.mp4

Vim Rc

2021-09-06T00:00:00-07:00

Vimrc file

Reload the vimrc with :so $MYVIMRC.

Sourced from various places.

You’ll need to do the first steps of the guide linked in [[setup.md]], namely:

git clone https://github.com/gmarik/Vundle.vim.git ~/.vim/bundle/Vundle.vim
Paste the vimrc below into ~/.vimrc
:PluginInstall
Follow YouCompleteMe install instructions

set nocompatible              " required
filetype off                  " required

" Install with :PluginInstall
" Uninstall with :PluginClean after commenting out/deleting the line
" set the runtime path to include Vundle and initialize
set rtp+=~/.vim/bundle/Vundle.vim
call vundle#begin()

" alternatively, pass a path where Vundle should install plugins
"call vundle#begin('~/some/path/here')

" let Vundle manage Vundle, required
Plugin 'gmarik/Vundle.vim'

" add all your plugins here (note older versions of Vundle
" used Bundle instead of Plugin)

" ...
Bundle 'Valloric/YouCompleteMe'
Plugin 'tmhedberg/SimpylFold'
Plugin 'vim-scripts/indentpython.vim'
" Plugin 'vim-syntastic/syntastic'
" Plugin 'nvie/vim-flake8'
Plugin 'jnurmine/Zenburn'
Plugin 'scrooloose/nerdtree'
Plugin 'kien/ctrlp.vim'
Plugin 'tpope/vim-fugitive'
Plugin 'Lokaltog/powerline', {'rtp': 'powerline/bindings/vim/'}
Plugin 'dense-analysis/ale'
Plugin 'vim-airline/vim-airline'
Plugin 'vim-airline/vim-airline-themes'

" All of your Plugins must be added before the following line
call vundle#end()            " required
filetype plugin indent on    " required

set splitbelow
set splitright

"split navigations
nnoremap <C-J> <C-W><C-J>
nnoremap <C-K> <C-W><C-K>
nnoremap <C-L> <C-W><C-L>
nnoremap <C-H> <C-W><C-H>

" Enable folding
set foldmethod=indent
set foldlevel=99

" Enable folding with the spacebar
nnoremap <space> za


au BufNewFile,BufRead *.py
    \ set tabstop=4 |
    \ set softtabstop=4 |
    \ set shiftwidth=4 |
    \ set textwidth=79 |
    \ set expandtab |
    \ set autoindent |
    \ set fileformat=unix


" au BufRead,BufNewFile *.py,*.pyw,*.c,*.h match BadWhitespace /\s\+$/

set encoding=utf-8


let g:ycm_autoclose_preview_window_after_completion=1
map <leader>g  :YcmCompleter GoToDefinitionElseDeclaration<CR>
let g:ycm_python_interpreter_path = '/usr/bin/python3'
let g:ycm_python_binary_path = '/usr/bin/python3'

" let g:syntastic_python_python_exec = 'python'
" let g:syntastic_python_checkers = ['pyflakes']

let python_highlight_all=1
syntax on
" default comment color is too dark.
hi Comment  guifg=#80a0ff ctermfg=darkred

set nu

set clipboard=unnamed

" free the cursor
set ve=all

" but show a good text width
set colorcolumn=80

let g:ale_fixers = {
            \ '*': ['remove_trailing_lines', 'trim_whitespace'],
            \ 'python': ['yapf', 'remove_trailing_lines', 'trim_whitespace'],
            \}
let g:ale_linters = {
            \ 'python': ['pylint'],
            \}
nmap <F10> :ALEFix<CR>
let g:ale_fix_on_save = 1
let g:ale_python_pylint_executable = 'pylint3'
let g:ale_sign_column_always = 1
let g:airline#extensions#ale#enabled = 1
let g:ale_echo_msg_error_str = 'E'
let g:ale_echo_msg_warning_str = 'W'
let g:ale_echo_msg_format = '[%linter%] %s [%severity%] "pylint: disable=%code%"'

set hlsearch
set backspace=indent,eol,start

Tmux Conf

2021-09-06T00:00:00-07:00

Tmux.Conf

Some good references about setting this up in a decent way. I won’t copy my rcfile here yet, but I’m basically using this one.

You can reload your conf file with ctrl-b and then :source-file ~/.tmux.conf, or in the shell tmux source-file ~/.tmux.conf.

# enable powerline
run-shell 'powerline-config tmux setup'

# vi keybindings
set-window-option -g mode-keys vi

# Set 256 color terminal
set -g default-terminal "screen-256color"

# split panes using | and -
bind | split-window -h
bind - split-window -v
unbind '"'
unbind %

# reload config file (change file location to your the tmux.conf you want to use)
bind r source-file ~/.tmux.conf

# switch panes using Alt-arrow without prefix
bind -n M-Left select-pane -L
bind -n M-Right select-pane -R
bind -n M-Up select-pane -U
bind -n M-Down select-pane -D

# Enable mouse mode (tmux 2.1 and above)
set -g mouse on

# don't rename windows automatically
set-option -g allow-rename off

######################
### DESIGN CHANGES ###
######################

# loud or quiet?
set -g visual-activity off
set -g visual-bell off
set -g visual-silence off
setw -g monitor-activity off
set -g bell-action none

#  modes
setw -g clock-mode-colour colour5
setw -g mode-style 'fg=colour1 bg=colour18 bold'

# panes
set -g pane-border-style 'fg=colour19 bg=colour0'
set -g pane-active-border-style 'bg=colour0 fg=colour9'

# statusbar
set -g status-position bottom
set -g status-justify left
set -g status-style 'bg=colour18 fg=colour137 dim'
set -g status-left ''
set -g status-right '#[fg=colour233,bg=colour19] %d/%m #[fg=colour233,bg=colour8] %H:%M:%S '
set -g status-right-length 50
set -g status-left-length 20

setw -g window-status-current-style 'fg=colour1 bg=colour19 bold'
setw -g window-status-current-format ' #I#[fg=colour249]:#[fg=colour255]#W#[fg=colour249]#F '

setw -g window-status-style 'fg=colour9 bg=colour18'
setw -g window-status-format ' #I#[fg=colour237]:#[fg=colour250]#W#[fg=colour244]#F '

setw -g window-status-bell-style 'fg=colour255 bg=colour1 bold'

# messages
set -g message-style 'fg=colour232 bg=colour16 bold'

Launchctl

2020-10-14T00:00:00-07:00

A few things about launchctl

You can use crontab again, so consider that.
You gotta enable bash or whatever to have access to the file system like this.
Remember that files for this live in ~/Library/LaunchAgents.

Pluck

2020-10-10T00:00:00-07:00

How to make a pluck sound

Short attack, 100-300 ms linear slope equivalent. Apply this to both filter and amp envelopes.
Low pass filter with some, or a lot of, resonance.
Use a sawtooth oscillator.
For more interest, have a couple of slightly out of tune (a couple of cents) sawtooths.

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Search

2020-09-01T00:00:00-07:00

Searching for quality

See dorking.

Basically, use the operators: ", +, (), | etc.

Cuda Install

2020-09-01T00:00:00-07:00

Installing CUDA

Install Ubuntu (I used 20.04 LTS).
Follow this

Jekyll Jemoji

2020-08-24T00:00:00-07:00

Jemoji

Include Emoji in jekyll projects with the jemoji. See here.

Exiftool

2020-08-23T00:00:00-07:00

Update exif information with Exiftool

Exiftool is pretty useful.

exiftool -Rights='New Owner Info' image.png

Some additional bits (2023-01-13) from here:

# List all metadata of a file (exif)
exiftool -s screenshot.png

# Remove GPS coords in a file
exiftool -gps:all= filename.jpg

# Clear out all metadata
exiftool -all= filename.jpg somesong.mp3

Some alternatives: https://imageoptim.com/mac and https://exiv2.org.

Shell Readlines Keys

2020-08-07T00:00:00-07:00

Readline keys

    # MOTD
    function echo_color() {
      local color="$1"
      printf "${color}$2\033[0m\n"
    }
    echo_color "\033[0;90m" "c-f  Move forward"
    echo_color "\033[0;90m" "c-b  Move backward"
    echo_color "\033[0;90m" "c-p  Move up"
    echo_color "\033[0;90m" "c-n  Move down"
    echo_color "\033[0;90m" "c-a  Jump to beginning of line"
    echo_color "\033[0;90m" "c-e  Jump to end of line"
    echo_color "\033[0;90m" "c-d  Delete forward"
    echo_color "\033[0;90m" "c-h  Delete backward"
    echo_color "\033[0;90m" "c-k  Delete forward to end of line"
    echo_color "\033[0;90m" "c-u  Delete entire line"

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Raspi Bridge Wifi

2020-08-05T00:00:00-07:00

Bridge the WiFi connection to the ethernet port

This one worked, with the addition of

sudo iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE
sudo iptables -A FORWARD -i wlan0 -o eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A FORWARD -i eth0 -o wlan0 -j ACCEPT

sudo sh -c "iptables-save > /etc/iptables.ipv4.nat"

From here

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Brew Path

2020-07-29T00:00:00-07:00

Brew Path

export PATH=/usr/local/bin:$PATH in .zshrc.

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Vim Spell

2020-07-28T00:00:00-07:00

Spell check

:set spelllang=en
:set spellfile=$HOME/.vim/spell/en.utf-8.add
:setlocal spell

Some commands:

]s and [s next and prev bad spelling
zg add to the good file
z= suggest good spellings

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Python Matplotlib Style

2020-07-28T00:00:00-07:00

Matplotlib default style

Use plt.style.use('seaborn-poster') for a big format that is easy for others to see. It’s a one-liner!

Python Coverage

2020-07-02T00:00:00-07:00

Coverage

Install with pip install coverage

Do coverage run --source=. -m unittest and coverage report.

Python Update

2020-07-01T00:00:00-07:00

Update packages

Use pip-review --local --interactive. I think?

Scientist

2020-07-01T00:00:00-07:00

On being a scientist

I found a lot of generic type knowledge to not be the sort of thing that was distributed to young scientists from the professors that I learned from. I have found some books that seems to discuss the types of things that I wish I would have known, sometimes as much as 20 years ago. Well, at least I found the books. Hopefully others can benefit from it too.

“Letters to a young scientist,” by E.O. Wilson
“The art of doing science and engineering: learning to learn,” by Richard Hamming (not finished yet, but the beginning is on point for this topic).

Learning

2020-07-01T00:00:00-07:00

Books about learning

“The 5 elements of effective thinking,” by Burger and Starbird
“How to solve it,” by G. Polya
“Mathematics and plausible reasoning,” vols 1 and 2, by G. Polya
“The art of insight in science and engineering,” by Sanjay Mahajan
“Streetfighting mathematics,” by Sanjay Mahajan

Python Cheatsheet

2020-06-30T00:00:00-07:00

Python Cheat Sheets

Some good ones:

GTO76 Comprehensive Python Cheatsheet

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Git Diff Staged

2020-06-20T00:00:00-07:00

Git Diff

Did you know that after you stage a commit, git diff won’t show the difference. The solution is git diff --staged obviously.

Python Requirements

2020-06-20T00:00:00-07:00

Requirements.txt

pip3 freeze > requirements.txt
pip3 install -r requirements.txt

Python Developing

2020-06-20T00:00:00-07:00

Developing Python

Mostly references for developing python.

Style: Google’s, PEP8.
Magic Methods

Some less well vetted guides:

Suggestions:

Make it easy to do it right: integrate linters and fixers with your editor.
Write and use tests.
Practice good design, as discussed in Code Complete.

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Vim Vundle

2020-06-19T00:00:00-07:00

Using Vundle

:PluginInstall

and

:PluginClean

Tmux Colors

2020-06-19T00:00:00-07:00

TMUX 256 colors

# Set 256 colors.
set -g default-terminal "screen-256color"

Find

2020-06-19T00:00:00-07:00

Find

Find is always a pita. I’ll collect some useful ones here.

find . -name '*.pyc' -delete

Firacode

2020-06-19T00:00:00-07:00

Fira Code

I’ve found fira to be a good monospace font.

Vim Ale

2020-06-18T00:00:00-07:00

Using ALE

I found ALE to be easier to configure than Syntastic. In particular:

let g:ale_fixers = {
            \ '*': ['remove_trailing_lines', 'trim_whitespace'],
            \ 'python': ['yapf', 'remove_trailing_lines', 'trim_whitespace'],
            \}
let g:ale_linters = {
            \ 'python': ['pylint'],
            \}
nmap <F10> :ALEFix<CR>
let g:ale_fix_on_save = 1
let g:ale_sign_column_always = 1
let g:airline#extensions#ale#enabled = 1
let g:ale_echo_msg_error_str = 'E'
let g:ale_echo_msg_warning_str = 'W'
let g:ale_echo_msg_format = '[%linter%] %s [%severity%]'
let g:ale_python_pylint_executable = 'pylint3'

" Some YouCompleteMe settings.
let g:ycm_python_interpreter_path = '/usr/bin/python3'
let g:ycm_python_binary_path = '/usr/bin/python3'

Remember to also add the airline plugins

Plugin 'vim-airline/vim-airline'
Plugin 'vim-airline/vim-airline-themes'

Rsync Only Some Filetypes

2020-06-14T00:00:00-07:00

Only sync some types of files

I’ll circle back when I figure out how to not sync directories that are empty.

rsync -avz --include="*/" --include="*.png"  --exclude="*" . /dest/dir

Raspi Hwrng

2020-06-14T00:00:00-07:00

Accessing the `hwrng`

Modern rasbperrypi’s have /dev/hwrng and rng-tools already installed. This is a pretty old post, but it has the salient details for making sure it is enabled and checking it. Also the bit about editing /etc/default/rng-tools to enable the device.

~~The device is only readable by root by default (probably can change this with chown, but I haven’t looked).~~ Update: this page has the details for making /dev/hwrng readable for users.

r = None
with open("/dev/hwrng", "rb") as d:
  r = d.read(10)

print(int.from_bytes(r, byteorder="big"))

Python Unittest

2020-06-14T00:00:00-07:00

Using `unittest` in python3

# test/test_module.py

import unittest
from library import module

class TestModule(unittest.TestCase):
  def test_function(self):
    self.assertTrue(module.function())

Call it from the shell with $>python3 -m unittest. Organizing test into a tree does require the __init__.py file in each subdir.

Zless

2020-05-26T00:00:00-07:00

`zless` unzips files into less

Vim Setup

2020-05-26T00:00:00-07:00

Easy setup of Vim

Just do this. And fix for python3 with this.

Shell Command Comments Hack

2020-05-17T00:00:00-07:00

Leave Notes To Self in Shell Comments

You can leave notes to yourself in comments in shell commands. This is helpful for understanding what is going on later. And maybe for searching your history.

cat example.txt # THIS THING IS GOOD

Emoji Input

2020-04-21T00:00:00-07:00

Emoji Input

Get to the emoji entry tool with ctrl-cmd-space. See here for reference.