cointoss3000

Description

You need to toss a coin. But why settle for the best of 3? cointoss3000 gives you the best of 3000.

Dependencies

• make
• go

Building

make

Usage

Typical usage (best of 3000)

./ct3

Sample output:

heads

Customise number of tosses

Simple customisation

Use -t <number of tosses>. For example, if you want the best of 3,

./ct3 -t 3

Extreme customisation

Of course, as the proud owner of cointoss3000, you won't want to limit yourself to a mere three coin tosses.

cointoss3000 is capable of tossing a coin up to 2^64 - 1 times. This will take a long time.

./ct3 -t 18446744073709551615

Overflows not allowed

Overflowing the uint64 is not allowed. Sorry, Matt Parker.

# not allowed
./ct3 -t 18446744073709551616

# not allowed
./ct3 -t -1

Verbose

If you want to know how many heads and tails you got, pass the -v flag.

./ct3 -v

Sample output:

heads: 1546
tails: 1454
winner: heads

Running as an HTTP server

cointoss3000 can be run as an HTTP server. It listens for GET / requests on a customisable port. To run it as a server, use the -s <port> flag. For example, to run it on port 8080,

./ct3 -s 8080

You can now curl it:

$ curl localhost:8080
tails

Note that other flags are not allowed when using the -s flag. Use the query parameters instead.

Query parameters

Verbose

You can set verbose output with the query parameter v. Example:

$ curl 'localhost:8080?v'
heads: 1459
tails: 1541
winner: tails

Number of tosses

You can set the number of tosses with the t= parameter. Example:

$ curl 'localhost:8080?v&t=3'
heads: 0
tails: 3
winner: tails

Note:

1. If the verbose flag is not set, only 1 toss is performed to save production CPU cycles.
2. The maximum number of tosses is 10,000 to prevent cointoss3000 from getting slammed in production.
3. Rate limiting is left as an exercise for the reader.

Licence

BSD 3-Clause. See LICENCE for full text.