Few little scripts

19 Dec, 2021

Just a few little scripts I have that help me with everyday life.

dev server

npx parcel pubilc/index.html

No config file required and the app automatically updates in the browser without refreshing the page.

deployment

rsync -a --stats -e "ssh -i /path/to/rsa_key" public/* user@host:/var/www/project

Sync a local directory with the remote server by making a recursive copy with respect to symlinks. Works great with static web sites.

download video description

yt-dlp -o "%(title)s--%(id)s--%(upload_date)s" \
       --playlist-start 1 \
       --playlist-end 5 \
       --write-description \
       --skip-download \
       https://www.youtube.com/playlist?list=PLtHtm5qCHV23Z7HVycqXBwKS8Y-jZ2d4S

Go through the last five episodes in a playlist and download their video description.

I run this script in a crontab job everyday to keep the list of podcast episodes on a website in sync with the original youtube channel.

crontab -e

00 12 * * * sh /buharog.live/download
10 12 * * * sh /buharog.live/release

By the way, I switched from youtube-dl to yt-dlp as it's actively maintained and less buggy.

download audio file

yt-dlp -f 'ba' -x --audio-format mp3 https://www.youtube.com/watch?v=Vnpp5NRi1Dg

or

yt-dlp -x https://www.youtube.com/watch?v=Vnpp5NRi1Dg
ffmpeg -i file.ogg file.mp3

30ms of silence

ffmpeg -i -acodec copy $1 -af "adelay=30ms:all=true" out.mp3

remove duplicates in mongodb collection

var ids = [];

db.collection.aggregate([
  {
    $group: {
      // group entries by "foo" attribute
      _id: { foo "$foo" },
      dups: { "$addToSet": "$_id" },
      count: { "$sum": 1 }
    }
  }, {
    // entries with same "foo" attribute values are duplicates
    $match: { count: { "$gt": 1 } }
  }
], {
  allowDiskUse: true
}).forEach(function (doc) {
  doc.dups.shift();
  doc.dups.forEach(function (dupId) {
    ids.push(dupId);
  })
})

printjson(duplicatesIds);

db.feed.remove({ _id:{$in:ids} });

two github users on one machine

# ~/.ssh/config

Host github.com
  HostName github.com
  User git
  IdentityFile ~/.ssh/id_rsa
    IdentitiesOnly yes

Host github.com-woopwoop
  HostName github.com
  User git
  IdentityFile ~/.ssh/id_rsa_woopwoop
    IdentitiesOnly yes

# ~/woopwoop/re/po/.git/config

[remote "origin"]
  url = git@github.com-woopwoop:re/po.git
  fetch = +refs/heads/*:refs/remotes/origin/*

Note woopwoop suffix — that's your second github user.