shelltricks

This is just my notebook of useful tricks for the UNIX/Linux command line shell / terminal.

(1) Documents and Multimedia

PDF things

See https://github.com/blairw/pdfworks

Convert HEIC to JPEG

sudo apt install libheif-examples
heif-convert -q 60 IMG_1234.HEIC IMG_1234.jpeg

Add 2px border

convert -border 2x2 -bordercolor '#999999' example.png example_border.png

From https://github.com/arp242/border/

Convert DOCX to PDF

The use of soffice requires LibreOffice, but then this should work:

soffice --headless --convert-to pdf:writer_pdf_Export "Blair Wang PhD Thesis rev03.docx"

If you need to catch multiple files, sometimes you cannot put the wildcard in that end part there, try this instead:

find . -type f -name "*.doc" -exec soffice --headless --convert-to pdf:writer_pdf_Export {} \;

Remove the first 15 minutes of a video file

ffmpeg -ss 00:15:00.000 \
	-i /Users/blair/Desktop/oneheartsunday200503_original.mp4 \
	-to 01:14:50.000 \
	-c copy ~/Desktop/oneheartsunday200503_shaved.mp4

Merge audio and video streams

The use of ffmpeg requires one to install it first (e.g., on Mac, brew install ffmpeg), but then this should work:

ffmpeg -i video_only.mp4 -i audio_only.m4a -c:v libx264 -c:a aac output_merged.mp4

(2) System Admin

Mass unzip zip files each into their own folder/directory

for file in *.zip; do unzip "$file" -d "${file%.zip}"; done

Credits to Jeff Fisher and Peter Flynn: https://stackoverflow.com/a/49856874

List all files (including hidden files) in current directory

# bash/zsh (Mac/Linux)
ls -lah

# Windows Powershell
gci -fo

Copy the current directory

# Mac
pwd | tr -d '\n' | pbcopy

# Linux
pwd | tr -d '\n' | xclip -selection clipboard

# Windows
$pwd.Path | Set-Clipboard

Find all files smaller than 16KB

find . -type f -size -16k

More info: https://superuser.com/a/204571

List of folders by size

This can either be done in one step:

du -h -d1 | sort -hr

Or in two steps:

du -h -d1 > du-h-d1.txt
cat du-h-d1.txt | sort -hr

The latter is handy on network drives where it may be useful to keep that record of the folder sizes. It's the du that takes a long time to run (cataloguing all your files and folders); the sort is very quick as it just reads the text output of the du.

Use rsync with specific SSH port

Handy to use in conjunction with SSHelper on Android, e.g.,

rsync -e 'ssh -p 2222' -av 192.168.1.221:/data/data/com.arachnoid.sshelper/files/home/SDCard/DCIM/Camera/ /Users/blair/Desktop/PhotosFromPhone

Find details for currently-running process

For example, to search for currently-running instances of rclone:

ps -ef | grep rclone

(3) Specific to macOS

Remove all the .DS_Store

Configuration:

defaults write com.apple.desktopservices DSDontWriteNetworkStores true

Ad hoc removal:

find . -type f -name '.DS_Store' -exec rm -rfv {} \;