View source for Launch rocket with countdown and acceleration in stdout

{{draft task}}

;Task:
Simulate the countdown of a rocket launch from &nbsp; '''5''' &nbsp; down to &nbsp; '''0''' &nbsp; seconds, &nbsp; and then display the moving, accelerating rocket on the standard output device as a simple ASCII art animation.
<br><br>

=={{header|8080 Assembly}}==

This program runs under CP/M. It assumes a terminal that understands the
ASCII CR, LF, and FF control codes (in practice this will be all of them).
If your machine has blinkenlights (e.g. an Altair 8800), the top half of the address bus
will additionally show a countdown going from 5 to 0 lights.

The 8080 is assumed to be clocked at 2 Mhz, which was the rated maximum
for the earlier chips. If you overclock your Altair, or run this program on a later Z80-based machine,
the countdown will go faster.  In a non-cycle-accurate emulator, the program will run in an instant. 
In SIMH, the command <code>d clock 2000</code> might help.

<syntaxhighlight lang="8080asm">	org	100h
	lxi	d,rocket	; Clear screen and print rocket
	mvi	c,9
	call	5
	mvi	a,0F8h		; Five lights
	lxi	h,number
cdwn:	lxi	d,count		; Print countdown
	call	sout
	call	sec		; Wait a second
	dcr	m		; Decrease number
	add	a		; Turn off a light
	jnz	cdwn		; Again (if not zero yet)
	lxi	d,flame		; Print flame
	call	sout
	mvi	c,24		; Lines
	lxi	h,20000		; Liftoff timer
lift:	lxi	d,newln
	call 	sout
	call	waithl
	lxi	d,-800
	dad	d
	dcr	c
	jnz	lift
	ret
sout:	push	psw		; Print string [DE] preserving registers
	push	b
	push	h
	mvi	c,9
	call	5
	jmp	rsto
	;;;	Busy wait counting down HL.
	;;;	52 + 24*HL cycles = 26 + 12*HL nanoseconds
waithl:	push	psw		; 11 cycles
	push	h		; 11 cycles
spin:	dcx	h		; 5 cycles    ----
	mov	a,h		; 5 cycles
	ora	l		; 4 cycles    loop
	jnz	spin		; 10 cycles   ----
	pop	h		; 10 cycles
	pop	psw		; 10 cycles
	ret			; 10 cycles
	;;;	Busy wait approximately one second (assuming 2Mhz clock)
	;;;	Pattern in A on address bus (will appear on blinkenlights
	;;;	if there are any). 
sec:	push	psw
	push	b
	push	h
	mov	b,a		; Set up for pattern
	lxi	h,25000		; 25.000 * 80 = 2.000.000 cycles ~= 1 sec 
swait:	ldax	b		; 56 cycles, and hold pattern on blinkenlights
	ldax	b               ; ...
	ldax	b
	ldax	b
	ldax 	b
	ldax	b
	ldax 	b
	ldax	b
	dcx	h		; 5 cycles
	mov	a,h		; 5 cycles
	ora	l		; 4 cycles
	jnz	swait		; 10 cycles
rsto:	pop	h
	pop	b
	pop	psw
	ret
	;;;	Rocket
rocket:	db	12, 10,10,10,10,10, 10,10,10,10,10
	db	'        |',13,10
	db	'       / ',92,13,10
	db	'      / _ ',92,13,10
	db 	'     |.o ',39,'.|',13,10
	db	'     |',39,'._.',39,'|',13,10
	db 	'     |     |',13,10
	db	'   ,',39,'|  |  |`.',13,10 
	db	'  /  |  |  |  ',92,13,10
	db	'  |,-',39,'--|--',39,'-.|' ,13,10,'$'
flame:	db	'     *******        ',13,10
	db	'     .*****.',13,10
	db	'      .***.',13,10
	db	'       .*.',13,10
	db	'        .',13,10,'$'
count:	db	'  _____ '
number:	db	'5 _____',13,'$'
newln:	db	13,10,'$'</syntaxhighlight>

=={{header|FreeBASIC}}==
<syntaxhighlight lang="freebasic">#define sky 32
dim as string rocket(1 to 7) = { "    ^",_
                                 "   / " + chr(92),_
                                 "  |   |",_
                                 "  | H |",_
                                 "  |   |",_
                                 " /|/ \|" + chr(92),_
                                 "/_||.||_" + chr(92) }

dim as double h = 0, dhdt = 0, d2hdt2 = 0.3, t, countdown = 5, dt
dim as integer ih, j, cut, lines 
cls
while countdown > 0
    t = timer
    print countdown,
    while timer < t + 1
    wend
    countdown -= 1
wend
cls

while h < sky
    lines = 0
    t = timer
    ih = int(h)
    for j = 1 to sky - 7 - h
        lines += 1
        print
    next j
    if ih < sky - 7 then cut = 6 else cut = sky - ih - 1
    for j = 7-cut to 7
        lines += 1
        print rocket(j)
    next j
    for j = sky-ih+1 to sky
        lines += 1
        print "   ***   "
    next j
    if lines < sky then print "   ***"
    print "-------------------"
    h += dhdt * dt
    dhdt += d2hdt2 * dt
    while t + 1./30 > timer
    wend
    cls
    dt = timer - t
wend</syntaxhighlight>

=={{header|Go}}==
{{trans|Rust}}
<br>
...though my rocket is a bit fancier :)
<syntaxhighlight lang="go">package main

import (
    "fmt"
    "time"
)

const rocket = `
    /\
   (  )
   (  )
  /|/\|\
 /_||||_\
`

func printRocket(above int) {
    fmt.Print(rocket)
    for i := 1; i <= above; i++ {
        fmt.Println("    ||")
    }
}

func cls() {
    fmt.Print("\x1B[2J")
}

func main() {
    // counting
    for n := 5; n >= 1; n-- {
        cls()
        fmt.Printf("%d =>\n", n)
        printRocket(0)
        time.Sleep(time.Second)
    }

    // ignition
    cls()
    fmt.Println("Liftoff !")
    printRocket(1)
    time.Sleep(time.Second)

    // liftoff
    ms := time.Duration(1000)
    for n := 2; n < 100; n++ {
        cls()
        printRocket(n)
        time.Sleep(ms * time.Millisecond)
        if ms >= 40 {
            ms -= 40
        } else {
            ms = 0
        }
    }
}</syntaxhighlight>

=={{header|Julia}}==
<syntaxhighlight lang="julia">rocket() = println("        /..\\\n        |==|\n        |  |\n        |  |\n",
    "        |  |\n       /____\\\n       |    |\n       |SATU|\n       |    |\n",
    "       |    |\n      /| |  |\\\n     / | |  | \\\n    /__|_|__|__\\\n       /_\\/_\\\n")

exhaust() = println("       *****")
cls() = print("\x1B[2J")
curup(n) = print("\e[$(n)A")
curdown(n) = print("\e[$(n)B")

function countdown(secs)
    print("Countdown...T minus ")
    for i in secs:-1:1
        print(i, "... ")
        sleep(1)
    end
    print("LIFTOFF!")
end

engineburn(rows) = (println("\n"); for i in 1:rows exhaust(); sleep(0.9^i); end)

testrocket() = (cls(); rocket(); curup(16); countdown(5); curdown(13); engineburn(30))

testrocket()
</syntaxhighlight>{{out}}
<pre>
Countdown...T minus 5... 4... 3...
        /..\
        |==|
        |  |
        |  |
        |  |
       /____\
       |    |
       |SATU|
       |    |
       |    |
      /| |  |\
     / | |  | \
    /__|_|__|__\
       /_\/_\
</pre>

=={{header|Nim}}==
{{trans|Julia}}
Using <code>terminal</code> module from standard library rather the escape codes.
<syntaxhighlight lang="nim">import os, math, terminal

proc rocket() =
  echo "        /..\\\n        |==|\n        |  |\n        |  |\n",
       "        |  |\n       /____\\\n       |    |\n       |SATU|\n       |    |\n",
       "       |    |\n      /| |  |\\\n     / | |  | \\\n    /__|_|__|__\\\n       /_\\/_\\\n"

proc exhaust() =
  echo "       *****"

proc countDown(secs: Natural) =
  stdout.write "Countdown...T minus "
  stdout.flushFile
  for i in countdown(secs, 1):
    stdout.write i, "... "
    stdout.flushFile
    os.sleep(1000)
  stdout.write "LIFTOFF!"
  stdout.flushFile

proc engineBurn(rows: Natural) =
  echo '\n'
  for i in 1..rows:
    exhaust()
    sleep (0.9^i * 1000).toInt

proc testRocket() =
  eraseScreen()
  rocket()
  cursorUp(16)
  countDown(5)
  cursorDown(13)
  engineBurn(30)

testRocket()</syntaxhighlight>

{{out}}
Same as Julia program output.

=={{header|Pascal}}==
Pascal includes the standard routine <tt>page</tt>.
However its specific behavior is implementation-defined, i. e. up to the compiler vendor.
''An'' implementation of <tt>page</tt> ''could'', for instance, translate into <tt>\014</tt> (ASCII form feed) or <tt>\033[2J\033[H</tt>, the ANSI escape sequence blanking the entire screen and moving the cursor to the upper left-hand corner.
If the terminal interprets them properly, the following <tt>program</tt> could satisfy the task’s requirements:
<syntaxhighlight lang="pascal">program launchRocketWithCountdownAndAccelerationOnOutput(output);

const
	screenWidth = 80;

type
	wholeNumber = 0..maxInt;
	natural = 1..maxInt;

var
	n: wholeNumber;

{
	Pascal, as defined by ISO standard 7185, does not provide any
	facilities to time actions. Nevertheless, most compiler vendors
	invented their own `sleep` or `delay` procedures.
}
procedure sleep(n: natural);
begin
	{ Yes, in Pascal an empty statement is valid. }
	{ There is really nothing after `do`. }
	for n := n downto 1 do
end;

procedure drawRocket(column: natural);
begin
	{ `page` is shorthand for `page(output)`, }
	{ as is `writeLn(…)` shorthand for `writeLn(output, …)`. }
	page;
	{ It should be an easy feat to adapt this to contain ASCII only. }
	writeLn(' ':column, '🙮')
end;

{ === MAIN ============================================================= }
begin
	for n := 5 downto 0 do
	begin
		drawRocket(1);
		writeLn;
		writeLn(n);
		sleep(5318008)
	end;
	
	n := 1;
	while n < screenWidth do
	begin
		n := round(n * 1.5);
		sleep(58008);
		drawRocket(n)
	end
end.</syntaxhighlight>Note, conventionally main engines (liquid fuel) are ignited a few seconds prior liftoff and SRBs are ignited just at/before liftoff, so the graphical depiction of exhaust visible at T−5 is ''about'' accurate.

=={{header|Perl}}==
{{trans|Raku}}
<syntaxhighlight lang="perl">use strict;
use warnings;
use Time::HiRes qw(sleep);

$SIG{INT} = \&clean_up;

my ($rows,$cols) = split /\s+/, qx/stty size/;
my $v =  $rows - 9;
my $h =  int $cols / 2 - 4;
my $a =  0;
my $i =  0;
my $j =  0;
my $t = -5;
my $start = $^T;

my @r = (q'   |',    q'  /_\\',   q'  | |',   q' /| |\\', q'/_|_|_\\');
my @x = (q' (/|\\)', q' {/|\\}',  q'  \\|/',  q'   |');
my @y = (q'  /|\\',  q' // \\\\', q' (/ \\)', q'  \\ /');

my $sp = ' ' x $h;

my $altitude = 0;
my $velocity = 0;

my @pal = ("\e[38;2;255;0;0m", "\e[38;2;255;255;0m", "\e[38;2;255;155;0m");
use constant W => "\e[38;2;255;255;255m";

print "\e[?25l\e[48;5;232m";

while (1) {
    if ($t >= 0) {
        $velocity = 5 * $t**2;
        $altitude = $velocity * $t / 2;
        $a = int 0.5 + ($altitude / $v);
    }
    clean_up() if $a > $rows + 5;

    print "\e[H\e[J", ("\n")x$v, W, $sp, join("\n$sp",@r), "\n", $sp;

    if ($t < 0) {
        print q'\\/   \\/'
    } else {
        exhaust( $pal[$i], $a )
    }
    print W, "\n", '▔' x $cols, $pal[1];
    printf "\n Time: T %-4s %9s  Altitude: %6.2f meters  Velocity: %5.1f m/sec\n",
    $t < 0 ? '- ' . int 0.5 + abs $t : '+ ' . int 0.5 + $t,
    $t < 0 ? '' : $a == 0 ? 'Ignition!' : 'Lift-off!',
    sprintf('%.2f', $altitude), sprintf('%.1f', $velocity);

    ++$i;
    $i %= 3;
    ++$j;
    $j %= 2;
    $t = (time() - $start - 5);
    sleep .05;
}

sub exhaust {
    my($clr, $a) = @_;
    print q'\\/', $clr, q'/^\\', W, q'\\/';
    return if $a == 0;
    if ($a < 4) {
        print "\n", $clr,
        $sp, ( $j ? join("\n$sp", @x[0..$a-1]) : join("\n$sp", @y[0..$a-1]) )
    } else {
        print "\n", $clr,
        $sp, ( $j ? join("\n$sp",@x) : join("\n$sp",@y) );
        print "\n" x ($a-4);
    }
}

# clean up on exit, reset ANSI codes, scroll, re-show the cursor & clear screen
sub clean_up { print "\e[0m", ("\n")x50, "\e[H\e[J\e[?25h"; exit(0) }</syntaxhighlight>

=={{header|Phix}}==
<!--<syntaxhighlight lang="phix">-->
 <span style="color: #004080;">sequence</span> <span style="color: #000000;">rocket</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">split</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"""
      /\   
     /  \  
     |  |  
     |  |  
    /|/\|\ 
   /_||||_\
 """</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n"</span><span style="color: #0000FF;">)</span>
  
 <span style="color: #004080;">integer</span> <span style="color: #000000;">lines</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">l</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">t</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">10</span>
 <span style="color: #004080;">atom</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0.25</span>
  
 <span style="color: #008080;">while</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rocket</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">></span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
         <span style="color: #000000;">rocket</span><span style="color: #0000FF;">[$]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"T minus %d... "</span><span style="color: #0000FF;">,</span><span style="color: #000000;">t</span><span style="color: #0000FF;">)</span>
         <span style="color: #000080;font-style:italic;">-- allow console resize during countdown:</span>
         <span style="color: #000000;">lines</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">video_config</span><span style="color: #0000FF;">()[</span><span style="color: #004600;">VC_SCRNLINES</span><span style="color: #0000FF;">]</span>
         <span style="color: #008080;">if</span> <span style="color: #000000;">l</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">lines</span><span style="color: #0000FF;">-</span><span style="color: #000000;">7</span> <span style="color: #008080;">then</span> <span style="color: #000000;">l</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">else</span>
         <span style="color: #008080;">if</span> <span style="color: #000000;">l</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
             <span style="color: #000000;">rocket</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">rocket</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">..$]</span>
         <span style="color: #008080;">else</span>
             <span style="color: #000000;">l</span> <span style="color: #0000FF;">-=</span> <span style="color: #0000FF;">(</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rocket</span><span style="color: #0000FF;">)></span><span style="color: #000000;">6</span><span style="color: #0000FF;">)</span>
             <span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rocket</span><span style="color: #0000FF;">)<</span><span style="color: #000000;">12</span> <span style="color: #008080;">then</span>
                 <span style="color: #000000;">rocket</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rocket</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"     **     "</span><span style="color: #0000FF;">)</span>
             <span style="color: #008080;">elsif</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rocket</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">12</span> <span style="color: #008080;">then</span>
                 <span style="color: #000000;">rocket</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rocket</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"       "</span><span style="color: #0000FF;">)</span>
             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #000000;">s</span> <span style="color: #0000FF;">*=</span> <span style="color: #000000;">0.95</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">l</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
         <span style="color: #7060A8;">clear_screen</span><span style="color: #0000FF;">()</span>
         <span style="color: #7060A8;">cursor</span><span style="color: #0000FF;">(</span><span style="color: #004600;">NO_CURSOR</span><span style="color: #0000FF;">)</span>
         <span style="color: #000000;">l</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">lines</span><span style="color: #0000FF;">-</span><span style="color: #000000;">7</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #7060A8;">position</span><span style="color: #0000FF;">(</span><span style="color: #000000;">l</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
     <span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rocket</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n"</span><span style="color: #0000FF;">))</span>
     <span style="color: #7060A8;">sleep</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">)</span>
     <span style="color: #000000;">t</span> <span style="color: #0000FF;">-=</span> <span style="color: #000000;">1</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span> <span style="color: #000000;">rocket</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">rocket</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..$-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
 <span style="color: #7060A8;">cursor</span><span style="color: #0000FF;">(</span><span style="color: #004600;">BLOCK_CURSOR</span><span style="color: #0000FF;">)</span>
<!--</syntaxhighlight>-->

=={{header|Racket}}==

{{trans|Go}}

<syntaxhighlight lang="racket">#lang racket

(define rocket #<<EOF
   /\
  (  )
  (  )
 /|/\|\
/_||||_\
EOF
  )

(define (cls) (displayln "\x1B[2J"))

(define (print-rocket n)
  (displayln rocket)
  (for ([i (in-range n)]) (displayln "")))

(for ([i (in-range 5 0 -1)])
  (cls)
  (printf "~a =>\n" i)
  (print-rocket 0)
  (sleep 1))

(cls)
(printf "Liftoff!\n")
(print-rocket 1)
(sleep 1)

(for/fold ([ms 1000] #:result (void)) ([n (in-range 2 100)])
  (cls)
  (print-rocket n)
  (sleep (/ ms 1000))
  (if (>= ms 40) (- ms 40) 0))</syntaxhighlight>

=={{header|Raku}}==
(formerly Perl 6)
{{works with|Rakudo|2019.07.1}}
Uses ANSI graphics. Works best in a 24 bit ANSI terminal at least 80x24, though bigger is better.

This is a very simple simulation. It assumes a constant ~2G+ acceleration in a gravitational field; so net +10 meters per second². It completely neglects the effects of [[wp:Drag_(physics)|air friction]], [[wp:Impulse|impulse]], [[wp:Snap,_Crackle_and_Pop#Physics|snap, crackle & pop]] and has an unrealistically clean fuel burn (no contrail). It does however (unlike most of the entries at this time) start at the base of the terminal (on the ground) and go up, rather than starting at the top and dropping a contrail. It calculates and displays an accurate displacement and velocity over time and uses those to scale its vertical screen displacement. 

The motion is a little "notchy" as the vertical resolution in a terminal is rather low. Exits after the rocket leaves the visible area of the terminal. See the [https://github.com/thundergnat/rc/blob/master/img/rocket-perl6.gif example animated gif]

<syntaxhighlight lang="raku" line>signal(SIGINT).tap: { cleanup() }

my ($rows,$cols) = qx/stty size/.words;
my $v = floor $rows - 9;
my $h = floor $cols / 2 - 4;
my $a = 0;
my $start = now;
my $t = -5;
my $i = 0;
my $j = 0;

my @r = Q'   |',   Q'  /_\',  Q'  | |',  Q' /| |\', Q'/_|_|_\';
my @x = Q' (/|\)', Q' {/|\}', Q'  \|/',  Q'   |';
my @y = Q'  /|\',  Q' // \\', Q' (/ \)', Q'  \ /'; #'

my $sp = ' ' x $h;

my $altitude = 0;
my $velocity = 0;

my @pal = "\e[38;2;255;0;0m", "\e[38;2;255;255;0m", "\e[38;2;255;155;0m";
constant \W = "\e[38;2;255;255;255m";

print "\e[?25l\e[48;5;232m";

loop {
    if $t >= 0 {
        $velocity = 5 * $t²;
        $altitude = $velocity * $t / 2;
        $a = ($altitude / $v).round;
    }
    cleanup() if $a > $rows + 5;

    print "\e[H\e[J", "\n" xx $v, W, $sp, @r.join("\n$sp"), "\n", $sp;
    if $t < 0 {
        print Q'\/   \/'
    } else {
        exhaust( @pal[$i], $a )
    }
    print W, "\n", '▔' x $cols, @pal[1];
    printf "\n Time: T %-4s %9s  Altitude: %6.2f meters  Velocity: %5.1f m/sec\n",
    $t < 0 ?? "- {$t.round.abs}" !! "+ {$t.round}",
    $t < 0 ?? '' !! $a == 0 ?? 'Ignition!' !! 'Lift-off!',
    $altitude.round(.01), $velocity.round(.1);

    ++$i;
    $i %= 3;
    ++$j;
    $j %= 2;
    $t = (now - $start - 5);
    sleep .05;
}

sub exhaust ($clr, $a) {
    print Q'\/', $clr, Q'/^\', W, Q'\/'; #'
    return if $a == 0;
    if $a < 4 {
        print "\n", $clr,
        $sp, ( $j ?? @x[^$a].join("\n$sp") !! @y[^$a].join("\n$sp"))
    } else {
        print "\n", $clr,
        $sp, ( $j ?? @x.join("\n$sp") !! @y.join("\n$sp"));
        print "\n" x $a - 4;
    }
}

# clean up on exit, reset ANSI codes, scroll, re-show the cursor & clear screen
sub cleanup () {  print "\e[0m", "\n" xx 50, "\e[H\e[J\e[?25h"; exit(0) }</syntaxhighlight>

{{out|Sample output}}
See [https://github.com/thundergnat/rc/blob/master/img/rocket-perl6.gif rocket-perl6.gif] (offsite animated gif image)

=={{header|REXX}}==
This REXX program hard-codes the name of the (OS) command to clear the terminal screen &nbsp; ('''CLS''').
<syntaxhighlight lang="rexx">/*REXX pgm does a countdown and then display the launching of a rocket (ASCII animation)*/
parse arg cntDown .                              /*obtain optional argument from the CL.*/
if cntDown=='' | cntDown==","  then cntDown= 5   /*Not specified?  Then use the default.*/
  @. =                                           /* [↓]  glyphs for the rocket ship.    */
  @.1= '   /\   '
  @.2= '  |  |  '
  @.3= '  |  |  '
  @.4= '  |  |  '
  @.5= ' /|/\|\ '
  @.6= '/_||||_\'
                    do rs=1  while @.rs\==''     /*determine size of the rocket (height)*/
                    end   /*rs*/
rs= rs - 1                                       /*the true  rocket size  (height).     */
cls= 'CLS'                                       /*the command used to clear the screen.*/
parse value  scrsize()  with  sd sw .
sw= sw - 1                                       /*usable screen width on some systems. */
sd= sd - 3                                       /*   "      "   depth  "   "     "     */
air= sd - 1 - rs                                 /*"amount" of sky above the rocket.    */
say
      do j=cntDown  by -1  to 1                  /* [↓]  perform countdown; show rocket.*/
      cls                                        /*use this command to clear the screen.*/
      say  right(j, 9) 'seconds'                 /*display the amount of seconds to go. */
      call sky                                   /*display the sky above the rocket.    */
      call rocket                                /*display the rocket  (on the ground). */
      call delay 1                               /*wait one second during the countdown.*/
      end   /*j*/

say left('',9)       "liftoff!"                  /*announce liftoff of the rocket.      */
cls                                              /*use this command to clear the screen.*/
call sky                                         /*display the sky above the rocket.    */
period= 1
dt= period / sd                                  /*acceleration  (period is decreasing).*/
call rocket                                      /*display the rocket  (in flight).     */
             do  sd+4;      say                  /*"make" the rocket appear to fly.     */
             period= format(period-period*dt,,3) /*calculate the decrease in the period.*/
             call delay max(period, .001)        /*wait for a diminishing time interval.*/
             end   /*sd+4*/
exit                                             /*stick a fork in it, da rocket is gone*/
/*──────────────────────────────────────────────────────────────────────────────────────*/
sky:     do air;   say;  end  /*air*/;   return  /*display the sky above the rocket.    */
rocket:  do ship=1  for rs;   say left('', sw%2 - 5)  @.ship;   end  /*ship*/;      return</syntaxhighlight>
This REXX program makes use of &nbsp; '''SCRSIZE''' &nbsp; REXX program (or
BIF) which is used to determine the screen
<br>width and depth of the terminal (console).  &nbsp; Some REXXes don't
have this BIF.

The &nbsp; '''SCRSIZE.REX''' &nbsp; REXX program is included
here &nbsp; ───► &nbsp; [[SCRSIZE.REX]]. <br><br>

=={{header|Rust}}==
<syntaxhighlight lang="rust">
use std::{thread, time};

fn print_rocket(above: u32) {
	print!(
"  oo
 oooo
 oooo
 oooo
");
for _num in 1..above+1 {
 println!("  ||");
}
}

fn main() {

    // counting
    for number in (1..6).rev() {
        print!("\x1B[2J");
      	println!("{} =>", number);
        print_rocket(0);
	let dur = time::Duration::from_millis(1000);
        thread::sleep(dur);
    }

    // ignition
    print!("\x1B[2J");
    println!("Liftoff !");
    print_rocket(1);
    let dur = time::Duration::from_millis(1000);
    thread::sleep(dur);

    // liftoff
    let mut dur_time : u64 = 1000;
    for number in 2..100 {
    	print!("\x1B[2J");
        print_rocket(number);	
	let dur = time::Duration::from_millis(dur_time);
        thread::sleep(dur);
	dur_time -= if dur_time >= 30 {30} else {dur_time};
    }
}

</syntaxhighlight>

=={{header|Wren}}==
{{trans|Go}}
<syntaxhighlight lang="wren">import "timer" for Timer

var rocket = "
    /\\
   (  )
   (  )
  /|/\\|\\
 /_||||_\\
"

var printRocket = Fn.new { |above|
    System.write(rocket)
    if (above == 0) return
    for (i in 1..above) System.print("    ||")
}

var cls = Fn.new { System.write("\x1B[2J") }

// counting
for (n in 5..1) {
    cls.call()
    System.print("%(n) =>")
    printRocket.call(0)
    Timer.sleep(1000)
}

// ignition
cls.call()
System.print("Lifetoff !")
printRocket.call(1)
Timer.sleep(1000)

// liftoff
var ms = 1000
for (n in 2..99) {
    cls.call()
    printRocket.call(n)
    Timer.sleep(ms)
    ms = (ms >= 40) ? ms - 40 : 0
}</syntaxhighlight>

=={{header|zkl}}==
{{trans|Go}}
Uses ANSI terminal codes.
<syntaxhighlight lang="zkl">var [const] rocket=
#<<<
0'~
    /\
   (  )
   (  )
  /|/\|\
 /_||||_\
~,           flame="    **";
#<<<
 
fcn cls		 { print("\x1B[2J") }
fcn cursorUp(n)  { print("\e[%dA".fmt(n)) }
fcn cursorDown(n){ print("\e[%dB".fmt(n)) }
fcn cursor2Col(n){ print("\e[%dG".fmt(n)) }

fcn __main__{
   tall,tall := rocket.counts(), tall[tall.find("\n")+1];
   cls(); print(rocket); cursorUp(tall);

   // count down to ignition
   print("T minus: ");
   foreach n in ([5..1, -1]){ print(n," "); Atomic.sleep(1); }
   print("    Liftoff !"); cursorDown(tall); cursor2Col(1);
 
   // liftoff
   ms:=1.0;		// 1 sec
   do(25){
      println(flame); Atomic.sleep(ms);
      ms=(ms - 0.04).max(0);   // 40 milliseconds faster than last time
   }
}</syntaxhighlight>
{{out}}
<pre>
T minus: 5 4 3 2 1     Liftoff !
    /\
   (  )
   (  )
  /|/\|\
 /_||||_\
    **
    **
    **
    **
</pre>