Asciiquarium - Under The C

Asciiquarium is an aquarium/C animation in ASCII art. This is a C-port of Asciiquarium v1.1, see "Credits" below for the original authors.

Build and release targets:

• Linux
  • Terminal: amd64, arm64, armel, armhf, i386, riscv64
• MacOS
  • Terminal: arm64
• Windows
  • Terminal: amd64, arm64
  • Screensaver: amd64, arm64
• WebAssembly

It also renders to EBU Teletext (text and mosaic mode).

Dependencies

None.

From time to time, it is recommended to feed the fish.

Usage

underthec [-c [1.0|1.1]] [-s] [-t] [-p pace] [-m text|-] [-M color] [-P position] [-a definition]
underthec {-h|-v}

Short	Long	Parameter	Description
-a	--aquatic-life	<def>	decide what's in (see below)
-c	--classic	[1.0|1.1]	Asciiquarium 1.0 / 1.1 modes
-m	--message	<text>	background text. - for stdin
-M	--message-color	<color>	-m's text color (see below)
-P	--message-position	<pos>	-m's placement (see below)
-p	--pace <pace>		speed, 0.01-10 (default: 1)
-u	--uturn-chance	<N>	fish turn chance (default: 1 in 200)
-f	--fps	<N>	render fps, 1-120 (default: 10)
-s	--screensaver		(terminal) exit on any keypress
-t	--transparent		transparent background
	--teletext	<t42|ts>	Teletext to stdout (see below)
	--teletext-mode	<text|mosaic>	teletext glyphs, default: text
	--mcast	<GROUP:PORT>	MPEG-TS teletext multicast group
	--ttl	<N>	multicast TTL (default: 1)
	--iface	<if>	multicast interface
-h	--help		show usage
-v	--version		show version

Classic mode -c/--classic

• -c 1.0 (or bare -c): original 1.0 fish/monster look
• -c 1.1: upstream 1.1 fish/monster look, restricted to upstream's species

Not combinable with -a.

Text colors -M|--message-color

Valid text colors: red, green, blue, yellow, magenta, cyan, white, black. Capitalized first letter: bold.

Message position -P|--message-position

Value	Placement
middle	horizontally+vertically centered (default)
center	horizontally centered, vertical top
marquee	vertically centered, scrolls right to left, repeats
swim	top row, scrolls right to left, repeats
event	like swim, but takes turns with ducks/swans/ship/etc

Aquatic life -a/--aquatic-life

Define what's going on in your asciiquarium. It takes a comma-separated definition:

• fish=<N|auto>: number of fish (default: auto, sized to the terminal)
• flags, present=on, omitted=off: ducks, dolphins, ship, swan, kaiju, fishhook, submarine, whale, shark, jellyfish, monster, bigfish, swordfish, crab, seahorse

Default (no -a): every flag on, fish=auto. Example: -a fish=10,jellyfish,dolphins

Environment variables

Each mirrors a command-line option. If both an env var and its cmdline option are given, the cmdline option wins.

Variable	Mirrors
UNDERTHEC_FISH=auto|number	fish= from -a
UNDERTHEC_AQUATIC_LIFE=<def>	-a, except fish
UNDERTHEC_CLASSIC=1.0|1.1	-c
UNDERTHEC_MESSAGE=<text>	-m
UNDERTHEC_MESSAGE_COLOR=<color>	-M
UNDERTHEC_MESSAGE_POSITION=<pos>	-P
UNDERTHEC_PACE=<pace>	-p
UNDERTHEC_FPS=<N>	-f
UNDERTHEC_SCREENSAVER=0|1	-s
UNDERTHEC_UTURN_CHANCE=<N>	-u
UNDERTHEC_TRANSPARENT=0|1	-t
UNDERTHEC_TELETEXT=t42|ts	--teletext
UNDERTHEC_TELETEXT_MODE=text|mosaic	--teletext-mode
UNDERTHEC_MCAST=<GROUP:PORT>	--mcast
UNDERTHEC_MCAST_TTL=<N>	--ttl
UNDERTHEC_MCAST_IFACE=<if>	--iface

Key bindings

Key	Action
f	Feed: drop flakes for the fish
h	Help about keys
p	Pause / resume
r	Redraw (recreate everything with fresh random positions)
s	Settings. Arrow to move the selector, +/-/[space] to make changes
t	Toggle background transparency
q	Quit (^C works too)

SIGUSR1 also triggers a feed.

Windows screensaver

underthec.scr is a native Windows multi-monitor screensaver. Right-click it and choose "Install", or copy it to %windir%\System32, then select it in the screensaver settings.

Credits

• The original asciiquarium program and most of its design are by Kirk Baucom
• A lot of the ASCII art is by Joan Stark
• This is a direct port of cmatsuoka/asciiquarium
• Jellyfish if from nothub/asciiquarium

License

GPL-2.0-or-later, see LICENSE.