Oneliners

A Growing Collection of Linux Command Line One-Liners

Please believe me… this collection was really supposed to grow over time…

inside a direcotry show disk usage of all hidden files and directories and sort by size:

$ du $(ls .* -d | tail -n +3) -hs |sort -h

inside a direcotry show disk usage of all files and directories (also hidden) and sort by size. Exclude ‘garbage’ file.

$ du . -a -d 1 -h --exclude=garbage | sort -h

Tar all files in current directory, excluding ./DATA and ./.cache

$ tar --exclude=.cache -cvf home_miguel_20180216.tar .

Find files in ./ARCHIVE NOT belonging to a specific user: miguel

$ find ARCHIVE/ \! -user miguel

set folder/ permissions to Read/Browse only for owner recursively

$ sudo chmod -R u=r,g=,o= folder/
$ chmod -R u=rX,g=,o= folder/

find all mails from Boban when in the maildir full of mailboxes and print only short headers without bodies:

$ grepmail -H -B -Y ‘(^TO:|^From:)’ Boban *

not really a one-lier but will print 256 colors in a bash:

for i in {0..255} ; do
    printf "\x1b[48;5;%sm%3d\e[0m " "$i" "$i"
    if (( i == 15 )) || (( i > 15 )) && (( (i-15) % 6 == 0 )); then
        printf "\n";
    fi
done

Web Video and Audio

convert a video to the WebM container format, accommodating the VP8 video codec and the MP4 container accommodating the H.264 codec.

Providing this two versions of your video should result in a decent coverage according to: https://developer.mozilla.org/en-US/docs/Web/HTML/Supported_media_formats#Browser_compatibility

ffmpeg -i video.mp4 -vcodec vp8 mazeball.webm
ffmpeg -i video.mp4 -vcodec h264 mazeball.mp4

If you require an audio codec as well use Vorbis in WebM and AAC inside MP4 respectively.

Yet before making a final decision, consider that many modern devices have hardware to assist in video and audio decoding, saving on CPU and battery consumption.