Shortcodes y hacks personales

En este repositorio estoy juntando los pedazos de codigo que utilizo en mi día a día y en mis proyectos personales. Puede ser código que usé una vez para un caso especifico pero quisiewra resguardar y compartir las soluciones que encuentre. El codigo es de distintos programas y lenguajes, puede ser una configuracion de regex en powershell o un archivo con un programa matemático de Matlab.

Peace out!

Convierte DVD a MP4 usando FFmpeg

Codigo de Powershell para convertir los archivos de DVD con formato .VOB a .MP4 mediante FFmpeg, un multimedia framework.

Este código convierte recursivamente los archivos .VOB de la carpeta Videos. Los archivos entregados se encuentran en la misma ubicación de los archivos y con el mismo nombre a diferencia de la extension.

ls -Recurse '.\Videos' | Where { $_.Extension -eq ".VOB" } | ForEach { .\ffmpeg -i $_.FullName $_.FullName.Replace(".VOB", ".mp4") }

Floating point arithmetic representation in MatLab

Tarea.m I wrote this code for a computer class. The code runs on Matlab and given a number, using floating point arithmetic, if the numer can be represented, then it'll tell you how, and finally it'll show the Gray representation.

Open the Hardware and Devices Troublshooter on Windows 11

msdt.exe -id DeviceDiagnostic

Find out which process is using the folder using PowerShell

# Get all processes
$processes = Get-Process

# Loop through each process
foreach ($process in $processes) {
  # Try to get the path of the executable
  try {
    $path = $process.Path
  }
  catch {
    # Ignore any errors
    continue
  }

  # Check if the path contains the folder name
  if ($path -like "*Music*") {
    # Write the process name and path
    Write-Host "$($process.Name) - $path"
  }
}

This will output something like:

Spotify - C:\Users\lesli\AppData\Roaming\Spotify\Spotify.exe
iTunes - C:\Program Files\iTunes\iTunes.exe

Borra las carpetas vacias recursivamente en PowerShell

Get-ChildItem -Path $(Get-Location) -Recurse -Directory | Where-Object { $_.GetFileSystemInfos().Count -eq 0 } | Remove-Item -WhatIf -Force

Si estas seguro que quieres borrar, elimina el -WhatIf.

Borra los archivos ocultos que comienzan con un punto en PowerShell

1. Revisar archivos a eliminar

Get-ChildItem -Recurse -Force | Where-Object { $_.Name -match "^\." }

El resultado es algo como

  Directory: C:\Users\L\Documentos\THE BEST HITS OF THE 70s\Covers

Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
-a-h--        12/13/2013  10:06 PM           4096 ._VA - The Best Hits of 70'_Back.jpg
-a-h--        12/13/2013  10:06 PM           4096 ._VA - The Best Hits of 70'_CD.jpg
-a-h--        12/13/2013  10:06 PM           4096 ._VA - The Best Hits of 70'_Front.jpg

2. Eliminar

Get-ChildItem -Recurse -Force | Where-Object { $_.Name -match "^\." } | Remove-Item -Force
Get-ChildItem -Recurse -Force | Where-Object { $_.Name -match "*.db" } | Remove-Item -Force

Borra los folders vacíos en PowerShell

1. Ver folders a borrar

Get-ChildItem -Recurse -Path $srcPath -Directory | Where-Object { (Get-ChildItem $_.FullName -Force).Count -eq 0 }

2. Borrar

Get-ChildItem -Recurse -Path $srcPath -Directory | Where-Object { (Get-ChildItem $_.FullName -Force).Count -eq 0 } | Remove-Item -Force

How to strip the last N characters of a filename

To split the last 33 characters from filenames in a directory using PowerShell, you can follow these steps:

1. Get the List of Files: First, use the Get-ChildItem cmdlet to retrieve the list of files in the directory. For example:

$files = Get-ChildItem -Path "C:\Your\Directory\Path"

2. Rename the Files: Next, iterate through each file and rename it by removing the last 33 characters. You can use the .substring() method to achieve this. Here’s an example:

foreach ($file in $files) {
    $newName = $file.Name.Substring(0, $file.Name.Length - 33)
    Rename-Item -Path $file.FullName -NewName $newName
}

How to add the extension to files in a directory

This command retrieves all files in the current directory and renames them by appending the .md extension.

Get-ChildItem -File | Rename-Item -NewName {$_.Name + ".md"}

How to create a GIF from a folder using Magick

Magick es un software open source para manipular imagenes a traves de la terminal. Este código se encarga de crear un GIF a partir de una carpeta de imágenes. El comando se ejecuta desde la carpeta en cuestión.

magick convert -delay 10 -loop 0 *.jpg vahshirrockstars.gif

How to resize images from the Command Line

Using Magick. My first attempt

magick ds_logo_full_white.png -resize 800x800 ds_logo_full_white_800x800.png

adapt my command line to meet this requirements: Accepted file formats are PNG and JPEG. File must be less than 5 MB, and must be at least 576 by 576 pixels. Recommended size is 800 by 800 pixels

Try this modified command:

magick ds_logo_full_white.png -resize 800x800^ -gravity center -extent 800x800 -format png -strip ds_logo_full_white_800x800.png

What this does:

• -resize 800x800^ → Ensures the image scales to at least 800x800, maintaining aspect ratio.
• -gravity center -extent 800x800 → If the image is smaller than 800x800, it fills the remaining space by extending the canvas.
• -format png -strip → Saves it as a PNG while stripping unnecessary metadata (to keep file size down).

Creating backgrounds (rendering from the terminal)

Image Magick has that capability to render stuff...

can magick create a background image? create a nice background for Dollar Scholars. Accepted file formats are PNG and JPEG. File must be less than 5 MB, and must be at least 576 by 576 pixels. Recommended size is 800 by 800 pixels with the terminal command

magick -size 800x800 gradient:#0A662A-#9EE067 -gravity center -extent 800x800 -format png -strip background_dollar_scholars.png

What this does:

• Creates an 800x800 image → Meets website requirements.
• Uses a gradient from dark green (#0A662A) to bright money green (#9EE067) → Represents wealth & success.
• Centers and extends the image to ensure proper framing.
• Saves as PNG and removes metadata to keep the file size optimized.

How to transform a PDF to JPG/PNG with Magick

You need to have Ghostscript for Windows.

gswin64c -version

magick -density 300 -units PixelsPerInch "C:/Users/lesli/Downloads/ptree-20240311210354744049.pdf" -quality 95 "C:/Users/lesli/Downloads/output.jpg"

Start guinicorn in a virtual environment to run django locally

Add security key

echo "export SECRET_KEY='$(openssl rand -hex 40)'" > .DJANGO_SECRET_KEY

source .DJANGO_SECRET_KEY

cat .DJANGO_SECRET_KEY

Start virtual environment

source ~/env/bin/activate

Kill previous gunicorn process if existent

sudo killall gunicorn

Make sure log file exists for the values in the gunicorn config file

sudo mkdir -pv /var/{log,run}/gunicorn/

sudo chown -cR ubuntu:ubuntu /var/{log,run}/gunicorn/

Start gunicorn

gunicorn -c config/gunicorn/dev.py

See the gunicorn logfile for dev

tail -f /var/log/gunicorn/dev.log

Python Dictionaries

>>> a = dict(one=1, two=2, three=3)
>>> b = {'one': 1, 'two': 2, 'three': 3}
>>> 
>>> c = dict(zip(['one', 'two', 'three'], [1, 2, 3]))
>>> 
>>> d = dict([('two', 2), ('one', 1), ('three', 3)])
>>> e = dict({'three': 3, 'one': 1, 'two': 2})
>>> 
>>> f = dict({'one': 1, 'three': 3}, two=2)
>>
>>
>>> a == b == c == d == e == f
True

Using XLS in Pandas

See https://pandas.pydata.org/docs/getting_started/comparison/comparison_with_spreadsheets.html#data-structures