Copy a file - Windows style

Question

This challenge is inspired by xkcd:

Challenge:

You'll simulate the copying a large file (1 Gigabyte). The transfer rate will vary between 10 kB/second to 100 MB/second. Your task is to output the time remaining of the file transfer. The output should look like:

Time remaining: 03:12    (meaning it's 3 minutes and 12 seconds left)
Time remaining: 123:12   (meaning it's 2 hours, 3 minutes and 12 seconds left)
Time remaining: 02:03:12 (optional output, meaning the same as above)

Leading zeros need not be displayed for minutes and hours (optional), but must be shown for seconds. Showing the time remaining using only seconds is not OK.

The file transfer:

• The transfer rate will start at 10 MB/second.
• Every second, there will be a 30% chance that the transfer rate will change
• The new transfer rate should be picked randomly (uniform distribution) in the range [10 kB/s, 100 MB/s], in steps of 10 kB/s.

Note: You don't need to actually copy a file.

You may choose to use: 1 GB = 1000 MB, 1 MB = 1000 kB, 1 kB = 1000 B, or 1 GB = 1024 MB, 1 MB = 1024 kB, 1 kB = 1024 B.

Output:

• You start at 01:40, not 01:39.
• You display the time after the transfer rate changes, but before anything is transferred at that rate
• The seconds should be displayed as integers, not decimals. It's optional to round up/down/closest.
• You should clear the screen every second, unless that's impossible in your language.
• The output should be constant: Time remaining: 00:00 when the file transfer is over.

Example:

I have rounded up all decimal seconds. Assume the lines below are shown with 1 second in between, and the screen is cleared between each one:

Time remaining: 01:40  (Transfer rate: 10 MB/s)
Time remaining: 01:39      1 GB - 10 MB
Time remaining: 01:38      1 GB - 2*10 MB
Time remaining: 01:37      1 GB - 3*10 MB
Time remaining: 01:28:54   1 GB - 4*10 MB  (TR: 180 kB/s)
Time remaining: 01:28:53   1 GB - 4*10 MB - 180 kB
Time remaining: 01:28:52   1 GB - 4*10 MB - 2*180 kB  
Time remaining: 00:13      1 GB - 4*10 MB - 3*180 kB  (TR: 75 MB/s)
Time remaining: 00:12      1 GB - 4*10 MB - 3*180 kB - 75 MB
Time remaining: 00:11      1 GB - 4*10 MB - 3*180 kB - 2*75 MB
Time remaining: 00:10      1 GB - 4*10 MB - 3*180 kB - 3*75 MB
Time remaining: 00:09      1 GB - 4*10 MB - 3*180 kB - 4*75 MB
Time remaining: 00:08      1 GB - 4*10 MB - 3*180 kB - 5*75 MB
Time remaining: 14:09:06   1 GB - 4*10 MB - 3*180 kB - 6*75 MB  (TR: 10 kB/s)
Time remaining: 14:09:05   1 GB - 4*10 MB - 3*180 kB - 6*75 MB - 10 kB
Time remaining: 00:06      1 GB - 4*10 MB - 3*180 kB - 6*75 MB - 20 kB  (TR: 88.110 MB/s)
Time remaining: 00:05
Time remaining: 00:04
Time remaining: 00:03
Time remaining: 00:02
Time remaining: 00:01
Time remaining: 00:00     <- Transfer is finished. Display this.

Answer 1

Pyth - 70 68 bytes

K^T5J^T3W>KZ%." r3úBTê;¥
í".D/KJ60=J?<OT3O^T4J=-KJ.d1.

Try it online without sleeps.

Answer 2

PowerShell, 190 215 187 bytes

($t="Time remaining: ")+"00:01:42";for($f,$r=1gb,10mb;$f-gt0;$f-=$r){if((Random 10)-lt3){$r=(Random -mi 1kb -ma (10mb+1))*10}$t+[Timespan]::FromSeconds([int]($f/$r));sleep 1}$t+"00:00:00"

Try it online! (TIO doesn't support clearing screen between lines)

Sets our initial $file size and our initial transfer $rate to 1gb and 10mb/s, respectively. Then, so long as we still have $file remaining, we loop.

Inside the loop, the if selects a number from 0 to 9 inclusive, and if it's 0, 1, or 2 (i.e., 30% of the time), we change the rate. This picks a random integer between 1kb and 10mb then that's multiplied by 10 to get our step count.

We then leverage the FromSeconds static method from the TimeSpan .NET library to construct the time remaining. The output format of that call exactly matches the challenge requirements, so no need for additional formatting.

(Saved a bunch thanks to @ConnorLSW)

Answer 3

MATL, 78 bytes

Thanks to @Maltysen and @DigitalTrauma for corrections.

1e5 1e3`XK10&XxyXIy/t0>*12L/'MM:SS'XO'Time remaining: 'whD-r.3<?1e4Yr}K]I0>]xx

Try it at MATL Online! (you may need to press "Run" several times if it doesn't initially work).

The online interpreter times out after 30 seconds. You may want to change 10 (pause time in tenths of second) to something smaller such as 3 in order to increase speed of display

Explanation

1e5                  % Push 1e5: file size in 10-kB units
1e3                  % Push 1e3: initial rate in 10-kB/s units
`                    % Do...while
  XK                 %   Copy current rate into clipboard K (doesn't consume it)
  10&Xx              %   Wait 1 second and clear screen
  y                  %   Duplicate current file size onto the top of the stack
  XI                 %   Copy it to clipboard I (doesn't consume it)
  y                  %   Duplicate current rate onto the top of the stack
  /                  %   Divide. This gives the estimated remaining time in seconds
                     %   It may be negative in the last iteration, because the
                     %   "remaining" file size may have become negative
  t0>*               %   If negative, convert to 0
  12L/               %   Push 86400 and divide, to convert from seconds to days
  'MM:SS'XO          %   Format as a MM:SS string, rounding down
  'Time remaining: ' %   Push this string
  wh                 %   Swap, concatenate
  D                  %   Display
  -                  %   Subtract. This gives the new remaining file size
  r                  %   Push random number uniformly distributed in (0,1)
  .3<                %   Is it less than 0.3?
  ?                  %   If so
    1e4Yr            %     Random integer between 1 and 1e4. This is the new rate 
                     %     in 10-kB/s units
  }                  %   Else
    K                %     Push rate that was copied into clipboard K
  ]                  %   End
  I                  %   Push previous remaining file size from clipboard I
  0>                 %   Is it positive?
]                    % End. If top of the stack is true: next iteration
xx                   % Delete the two numbers that are on the stack

Answer 4

Ruby, 116 110 bytes

Try it online, except repl.it reads \r as a newline and also can't use $><< so it's replaced with its 5-byte equivalent, print.

Shoutout to JonasWielicki for the initial idea of using \r to reset the line.

f=1e5;r=1e3;(k=f/r=rand<0.3?1+rand(1e4):r;$><<"\rTime remaining: %02d:%02d"%[k/60,k%60];f-=r;sleep 1)while f>0

This version is untested on Windows, but works on Unix.

Answer 5

Bash + common utils, 117

Straightforward implementation. A few bytes saved by dividing out by 10000:

for((b=10**5,r=1000;b>0;r=RANDOM%10<3?RANDOM%10000+1:r,b-=r));{
clear
date -ud@$[b/r] "+Time remaining: %T"
sleep 1
}

Try it online. Using sleep 0 on the TIO so you don't have to wait. clear doesn't work on TIO.

Answer 6

JavaScript (ES6), 162 bytes

Shows minutes as is with padded seconds (floored)

E.g., 123:45

t=1e5
s=1e3
setInterval(c=>c.log(`Time remaining: ${c.clear(d=t/s),d/60|0}:`+`0${t-=s>t?t:s,r=Math.random,s=r()<0.3?1+r()*1e4|0:s,d%60|0}`.slice(-2)),1e3,console)

Answer 7

Python 3.6 (212 203 bytes)

from random import*
import time,datetime
r=1e7
d=1e9
while 1:
 print(f"\x1b[KTime remaining: {datetime.timedelta(seconds=d//r)}",end="\r");d=max(0,d-r);time.sleep(1)
 if random()>.7:r=randint(1,1e4)*1e4

Pretty straightforward, I think. Erases the line using ANSI escape sequence and K command.

• Saved 9 bytes thanks to @ValueInk

Answer 8

Batch, 193 bytes

@set/ap=10000,s=p*10,r=p/10
:l
@set/at=s/r,m=t/60,n=t%%60+100,s-=r
@cls
@echo Time remaining: %m%:%n:~1%
@timeout/t>nul 1
@if %random:~-1% lss 3 set/ar=%random%%%p+1
@if %t% gtr 0 goto l

Note: Slight bias towards rates of 27.68 MB/s or less.

Answer 9

C 184 171 155 bytes

f(){i,j=0,r=1e7;for(i=1e9;i>0;i-=r){j=i/r;printf("Time remaining: %02d:%02d:%02d\r",j/3600,(j/60)%60,j%60);sleep(1);if(rand()%10<3)r=(rand()%10000)*1e4;}}

I hope this qualifies.

Ungolfed version:

void f()
{
    int j=0;
    float rate=1e7; 
    for(int size=1e9;i>0; size-=rate)
    {     
       j=size/rate;      
       printf("Time remaining: %02d:%02d:%02d\r",j/3600,(j/60)%60,j%60);
       sleep(1);

       if(rand()%10<3)
          rate=(rand()%10000)*1e4;          



   }

}

Explanation: In the golfed version i corresponds to size in ungolfed version and r is rate in ungolfed version. j stores the time remaining in seconds.

• I have 10^9 bytes to copy. I start copying at the rate of 10 Megabytes/second,
• If the probablity is less than 30% , change the rate (from 10 kilobytes to 100 Megabytes per second)

@ValueInk Thanks for saving 13 bytes.

@nmjcman101 Thanks for saving 16 bytes.