GNU Coreutils

Apply Advanced GNU coreutils patch to display cp and mv commands with progress bars.

AWK

in 1970’s
Scripting languague to do quick and dirty tasks like counting and reporting from files.
awk is superset of grep
- shorter and better than writing python script

"MS-DOS was a pretty pathetic operating system" Microsoft has left the chat

Use cat <file> | grep -i is unoptimized. We are calling 2 programs. Use grep <pattern> <file>

cat is for concatination getting combined output from multiple files
- Use < as cat alternative

> will clear the contents of a the file. Use < with caution. Do not make type

How to write and install your own manpages?

MANPATH environment variable and tool

https://www.cyberciti.biz/faq/linux-unix-creating-a-manpage/

List Recursively?

ls -R

How to exclude a directory with ripgrep?

rg --pretty --files-with-matches abbr --glob '!docs/'

Test hash of downloads?

hash="some hash value from internet"
[[ $(sha256sum xyz.tar.gzip | awk '{print $1}') == ${hash} ]] \
    && echo "ok" \
    || echo "NOT OK"

extract audio from mkv files

find . -type f -name "*.mkv" \
    -exec bash -c 'FILE="$1"; \
    ffmpeg -i "${FILE}" -vn -c:a libmp3lame \
    -y "${FILE%.mkv}.mp3";' _ '{}' \;

convert whitespaces (tabs, spaces, newlines) to Newline characters

sed -r 's/\s+/\n/g'

add Album art to music files?

ffmpeg -i input.mp3 -i cover.jpg -map_metadata 0 -map 0 -map 1 output.mp3

ffprobe -show_streams -show_format DV06xx.avi
ffmpeg -i destination.mp4

ripgrep

rg
    --pretty (1)
    --files-with-matches (2)
    abbr
    --glob (3)
    '!docs/'

1	Use colors with pager `less`
2	files-without-matches is also an option
3	Do not include these directories in search