0pen is a command to open media or other files with geeky specifications on the order in which they are opened.

0pen can either:

• interactively play files with MPlayer, VLC, or any given command (supports Playtag);
• output a list of files that can be opened e.g. with feh for images or as a standard M3U playlist by any media player.

For a detailed list of available options, see help.txt or 0pen --help.

Shuffle all files under music/ (excluding dirs and files starting with +, ., _, or ~) and open them in succession with MPlayer, looping indefinitely (reshuffle between each loop). Only play audio even for video files:

0pen.ml music/ --music

Play all files under foo_fighters/ once, in alphabetical / "file-manager" order, i.e., in lexical order except 9.mp3 comes before 10.mp3:

0pen.ml foo_fighters/ --alpha

Play all files under comedy/, including dirs and files starting with +, picking them indefinitely at random. Each subdirectory's probability of being picked is proportional to the square root of the total number of (leaf) files it contains. As an exception, directories named in ALL_CAPS or starting with = or : have their children treated as if they were direct children of the parent directory.

0pen.ml comedy/ -+ --pick q

First play toto/africa.mp3, then randomly play files from foo_fighters/ and toto/. When picking files, both top-level directories foo_fighters/ and toto/ are picked as often as a single file (constant weight, so here it's 50 % foo_fighters and 50 % toto), then all further levels of subdirectories weigh as much as the total number of files they contain (linear weight):

0pen.ml foo_fighters/ toto/ --pick c/l --first toto/africa.mp3

Find photos modified (or taken) less than a year ago to open them as a full-screen slideshow. With each directory sorted alphabetically, move by the golden angle 1-1/φ ≈ 0.38 of the length of the list between picking files, which maximizes diversity. Pick series of 3 consecutive photos if possible (File names are considered consecutive if they differ only by one number or sequence of numbers, extension and name tags excluded. For instance, IMG_101_1.webp and IMG_105_2[cats].jpg are consecutive but IMG_106_2_Cat.jpg isn't.):

find photos/ -mtime -365 | 0pen.ml --pick ag --series 3 | feh -Ff -

Shuffle files found under comedy/, write a list of the first 100 files, and open the list with VLC (0pen can also open each file in VLC separately with --vlc.):

0pen.ml comedy/ -n 100 >tmp.m3u8 && vlc tmp.m3u8

0pen requires OCaml >= 4.14 with ocamlfind, batteries, dolog, magic-mime, ubase, uucp, and uutf.

Using opam on Ubuntu, installing from the ground up could look something like:

sudo apt install opam
opam init
opam switch create 5.0
opam install ocamlfind batteries dolog magic-mime ubase uucp uutf

# and then, for instance
ln -s $HOME/Downloads/0pen/0pen ~/bin/
# or
sudo cp 0pen.ml /usr/local/bin/0pen

To open files indefinitely, like mplayer -loop 0. I pronounce it "zeropen".