Bitcoin Wiki - User contributions [en]

Talk:Bitcoin symbol

2011-07-21T12:04:06Z

Pander:

== ϭ has relation to bitcoin ==

ϭ actually does have a visible relation to bitcoin, seeing as it is the lower-case russian B. :)

== Pros and cons as different collums? ==

I think it would be better if the pros and cons were in sepparate colums to make it easier to evaluate the proposals; what do you say? --[[User:TiagoTiago|TiagoTiago]] 15:23, 26 April 2011 (GMT)

== Removal of section called Existing Unicode symbol ==

Unless good reason are given, I would like to delete the section called "Existing Unicode symbol" [[User:Pander|Pander]] 12:04, 21 July 2011 (GMT)

Bitcoin symbol

2011-07-19T21:36:13Z

2011-07-19T16:52:01Z

Pander: /* Submissions */

== Currency code ==
The [https://secure.wikimedia.org/wikipedia/en/wiki/ISO_4217 currency code] for Bitcoin is '''BTC'''. However, at the moment it is an [https://secure.wikimedia.org/wikipedia/en/wiki/ISO_4217#Without_currency_code unofficial code] according to the ISO 4217 standard but the official code according to the Bitcoin community.

A [https://forum.bitcoin.org/index.php?topic=7205.msg112577 request] has been made at the [http://www.six-group.com/ organization] maintaining the currency codes in the ISO 4217 standard to support BTC. This has been declined mainly on bases that organizations such as [https://secure.wikimedia.org/wikipedia/en/wiki/Reuters Reuters] and [https://secure.wikimedia.org/wikipedia/en/wiki/Bloomberg Bloomberg] are not reporting on the Bitcoin currency. when this changes a request can be resubmitted.

== Currency sign ==

There is no official currency sign for Bitcoin as of December 2010. As an alternative, the BTC currency code can be used. Some existing Unicode symbols have been proposed but also serious work is being done on creating a custom Bitcoin sign with its own official [https://secure.wikimedia.org/wikipedia/en/wiki/Unicode Unicode] that is recognized by the [https://secure.wikimedia.org/wikipedia/en/wiki/Unicode_Consortium Unicode Consortium]. Note that a currency sign is more complex than creating a logo as will be explained below.

=== New Unicode symbol ===

In some discussions [https://forum.bitcoin.org/index.php?topic=41.0 41], [https://forum.bitcoin.org/index.php?topic=369.0 369] and [https://forum.bitcoin.org/index.php?topic=7215.0 7215] on the bitcoin forum several designs of an official Bitcoin sign have been proposed. This section on the Wiki is intended to streamline the process of arriving at an official Bitcoin currency sign with its own Unicode character code.

==== Goal ====
Having a unique Bitcoin currency sign will allow typographers to add their currency sign design in their fonts. This is similar as implementing support for the euro sign. Each font has its own version of the euro sign that fits with the style observed in the characters in the rest of the fonts of their typefaces. Note that the Unicode Consortium does not endorse Bitcoin in any way by assigning a Unicode character code, however, having a Unicode for the Bitcoin sign will also be good for PR and help having Bitcoin be taken more seriously.

==== Requirements and criteria ====

A reference Bitcoin sign could/should/must be:
* recognizable as a [https://secure.wikimedia.org/wikipedia/en/wiki/Currency_sign currency sign] such as $ € ¥ £ ¢ (with one or two vertical or horzontal bars)
* not confusing with existing currency sign such as Thai Bath ฿
* build from recognizable existing characters found on most [https://secure.wikimedia.org/wikipedia/en/wiki/Keyboard_layout#United_States QWERTY keyboards] such as bar |, minus -, hash # and/or capital B referring to currencies and '''B'''itcoin
* easy to use in handwriting
* easy to compose with one or more [https://help.ubuntu.com/community/GtkComposeTable#The%20Gtk%20Compose%20Table compose seuquences] that are still free and refer to the elements recognizable in the sign (For example the euro sign can be composed from = and C even though the = and C are not part of how it is pronounced.)
* ''possible'' to implement in [https://secure.wikimedia.org/wikipedia/en/wiki/Serif serif and sans-serif] (Most of the [http://www.unicode.org/charts/PDF/U20A0.pdf Unicode reference implementations] are made with serifs but sans-serif also exist in sans-serif fonts. So a reference implementation in serif to what is found in the PDF is preferred.)
* ''possible'' to implement in regular, italic, bold and bold italic (for sans-serif the italic will simply be a slanted version)
* in [https://secure.wikimedia.org/wikipedia/en/wiki/SVG SVG] and use this [http://pastebin.com/raw.php?i=FVY8W1W3 template] (save as bitcoin-sign-20110719-template.svg) with updated metadata and public domain or similar free/open/libre license

Note that a reference Bitcoin sign will only be used as a reference by the Unicode Consortium and it is up to typographers to implement their version matching the style of their typefaces and fonts.

==== Submissions====

It is possible to submit proposals for a '''reference implementation''' below until (community must determine date). They will be judged by (community must form committee for this). If you have problems submitting your design, ask a friend with knowledge on editing wikipedia for help.

{| class="wikitable sortable"
|-
! Preview !! Handwritten !! Associations !! Compose sequence(s) !! Designer !! Link to SVG file !! Notes
|-
| [[file:Bitcoin-proposal-1.png|128px]]
|| [[file:Hashbtc.jpg|128px]]
|| hash (#), numeral three (3)
|| B#, #B, 3#, #3
|| wareen
|| TODO
|| preliminary submission, update will be submitted
|-
| [[File:Bitcoin-sign-20110719.png|128px]]
|| [[file:Img075.jpg|128px]]
|| double barred dollar sign ($), capital b (B)
|| B|, |B, B=, =B
|| Pander
|| [http://pastebin.com/raw.php?i=XYsc9DeS bitcoin-sign-20110719.svg]
|| example submission based on [[File:F33980a445.png]]
|}

=== Existing Unicode symbol ===

There is a discussion over [http://www.bitcoin.org/smf/index.php?topic=369.0 which Unicode symbol might be the best suited] for bitcoin.

To type Unicode characters, refer to:

* [[Microsoft Windows Unicode Input]]
* [[How to easily type the circled B symbol on a Mac]]

It has led to the following options:

{| class="wikitable sortable"
|-
! Proposed character !! Description & Pros & Cons !! Unicode name !! Unicode decimal input !! Unicode hex input
|-
| ฿ ||
* Pros: Gives a currency-like look (it is the symbol for an existing currency, the Thai Baht, but other currency symbols often get reused, like the $); displayed correctly on all known OSes
* Cons: It is already used for the Thai currency, and might confuse people
|| THAI CURRENCY SYMBOL BAHT || || Alt +0E3F
|-
| Ⓑ ||
*Pros: Similar to current bitcoin.org logo
|| CIRCLED LATIN CAPITAL LETTER B || || Alt +24B7
|-
| B⃫ ||
|| LATIN CAPITAL LETTER B + COMBINING LONG DOUBLE SOLIDUS OVERLAY || U+0042 U+20EB
|-
| B⃦ ||
*Pros: Similar to current bitcoin.org logo
|| LATIN CAPITAL LETTER B + COMBINING DOUBLE VERTICAL STROKE OVERLAY || U+0042 U+20E6
|-
| ⓑ ||
*Pros: Small b represent the unit bit in computer where capital B is Byte
* Cons: Small fonts are harder to read
|| CIRCLED LATIN SMALL LETTER B || ||Alt +24D1
|-
|ᴃ|| || LATIN LETTER SMALL CAPITAL BARRED B || ||Alt +1D03
|-
|Ƀ||
*Pros: [http://www.ecogex.com/bitcoin/ See the project Ƀ Another Bitcoin identity]
|| LATIN CAPITAL LETTER B WITH STROKE || ||Alt +0243
|-
|B⃦|| || || ||
|-
|␢|| || (Unicode Block: Control Pictures) BLANK SYMBOL (graphic for space) || || Alt +2422
|-
|-
| 币 || pronounced "bi", combines "b", turned "c" and "T", many Chinese users, also 网民币 - Wangminbi, "The Netizen's Currency" (pun on Renminbi) || Chinese for "Currency" || || U+5E01
|-
| β ||
*Pros: Fluid look and easy to write; Lowercase
|| GREEK SMALL LETTER BETA || ||Alt +03B2
|-
|¤|| || CURRENCY SIGN ||Alt 0164 ||Alt +00A4
|-
|Ƅ|| || LATIN CAPITAL LETTER TONE SIX || ||Alt +0184
|-
|∄|| || (Unicode Block: Mathematical Operators) THERE DOES NOT EXIST || ||Alt +2204
|-
|ઘ|| || GUJARATI LETTER GHA (Indo-Aryan language) || ||Alt +0A98
|-
|ϭ|| || (Unicode Block: Greek and Coptic) COPTIC SMALL LETTER SHIMA || ||Alt +03ED
|-
| ɸ || contains 0 and I || Greek small Theta || || U+0278
|-
| ∆ || delta for "digital" || Greek capital Delta || || U+0394
|-
|[[Image:Bitcoin Symbol Suggestion circled struck-through B.png|20px]]||
* Cons: Does not exist in the Unicode standard
|| || ||
|-
|[[Image:Bitcoin Symbol Suggestion rotated power.png|20px]]||
* Cons: Does not exist in the Unicode standard
|| || ||
|-
|ⓢ|| Purposed as a smaller unit of bitcoin. E.g. A hundredth of a bitcoin || CIRCLED LATIN SMALL LETTER S || || Alt +24E2
|-
|≡ || three bars like three bits || || || Alt + 240
|-
|[[Image:Bat.png|32x32px|alt=The b'at]]
the b'at
||
* Pros: Is round like a coin. Contains the B for Bitcoin. Borrows a style widelly associated with the internet. Not used for other meanings.
* Cons: Does not exist in the Unicode standard
|| || ||
|-
|A 'C' with '1' and '0' inside [[http://img829.imageshack.us/img829/8840/bitcoinlogodraft.png]]||
* Cons: Does not exist in the Unicode standard
|| || ||
|-
|A 'C' with a 'circle' and 'dot' inside [[http://img836.imageshack.us/img836/6006/bitcoinlogodraftii.png]]||
* Cons: Does not exist in the Unicode standard
|| || ||
|-
| ◪|| || (Unicode Block: Geometric Shapes) SQUARE WITH LOWER RIGHT DIAGONAL HALF BLACK || || Alt +25EA
|-
|[[http://hosting11.imagecross.com/image-hosting-61/2381unicode1s.png]][[http://hosting11.imagecross.com/image-hosting-61/162bitcoin_uni_s.png]]||
* Cons: Does not exist in the Unicode standard
|| || ||
|-
|☺|| ||WHITE SMILING FACE|| || Alt +263A
|-
|☻|| ||BLACK SMILING FACE|| || Alt +263B
|-
|㋡|| ||CIRCLED KATAKANA TU' (Japanese)|| || Alt +32E1
|}

2011-07-19T16:30:46Z

Pander:

2011-03-31T10:11:55Z

Pander: /* Python */ comment out line that could trigger unintended transfer of 10 BTC

== Controlling Bitcoin ==

Run ''bitcoind'' or ''bitcoin -server''. You can control it via the command-line or by HTTP-JSON-RPC commands.

You must create a bitcoin.conf configuration file setting an rpcuser and rpcpassword; see [[Running Bitcoin]] for details.

Now run:
$ ./bitcoind
bitcoin server starting
$ ./bitcoind help
# shows the help text

A [[Original Bitcoin client/API Calls list|list of RPC calls]] will be shown.

$ ./bitcoind getbalance
2000.00000

== JSON-RPC ==

Running Bitcoin with the -server argument (or running bitcoind) tells it to function as a [http://json-rpc.org/wiki/specification|HTTP JSON-RPC] server, but
[http://en.wikipedia.org/wiki/Basic_access_authentication|HTTP Basic access authentication] must be used when communicating with it, and, for security, by default, the server only accepts connections from other processes on the same machine. If your HTTP or JSON library requires you to specify which 'realm' is authenticated, use 'jsonrpc'.

Bitcoin supports SSL (https) JSON-RPC connections beginning with version 0.3.14. See the [[Enabling SSL on original client daemon|rpcssl wiki page]] for setup instructions and a list of all bitcoin.conf configuration options.

To access the server you should find a [http://json-rpc.org/wiki/implementations|suitable library] for your language.

== Proper money handling ==

See the [[Proper Money Handling (JSON-RPC)|proper money handling page]] for notes on avoiding rounding errors when handling bitcoin values.

== Python ==

Save the following file as jsonrpc.py.

<source lang="python">
import urllib
import decimal
import json

class JSONRPCException(Exception):
def __init__(self, rpcError):
Exception.__init__(self)
self.error = rpcError

class ServiceProxy(object):
def __init__(self, serviceURL, serviceName=None):
self.__serviceURL = serviceURL
self.__serviceName = serviceName

def __getattr__(self, name):
if self.__serviceName != None:
name = "%s.%s" % (self.__serviceName, name)
return ServiceProxy(self.__serviceURL, name)

def __call__(self, *args):
postdata = json.dumps({"method": self.__serviceName, 'params': args, 'id':'jsonrpc'})
respdata = urllib.urlopen(self.__serviceURL, postdata).read()
resp = json.loads(respdata, parse_float=decimal.Decimal)
if resp['error'] != None:
raise JSONRPCException(resp['error'])
else:
return resp['result']
</source>

Python-jsonrpc automatically generates Python methods corresponding to the functions above.

<source lang="python">
from jsonrpc import ServiceProxy

access = ServiceProxy("http://user:password@127.0.0.1:8332")
access.getinfo()
access.listreceivedbyaddress(6)
#access.sendtoaddress("11yEmxiMso2RsFVfBcCa616npBvGgxiBX", 10)
</source>

== Ruby ==

<source lang="ruby">
=begin
Make sure to do:
gem install rest-client

Usage:
h = ServiceProxy.new('http://user:password@127.0.0.1:8332')
puts h.getinfo.call
puts h.getbalance.call '0'
=end
require 'json'
require 'rest_client'

class JSONRPCException < RuntimeError
def initialize()
super()
end
end

class ServiceProxy
def initialize(service_url, service_name=nil)
@service_url = service_url
@service_name = service_name
end

def method_missing(name, *args, &block)
if @service_name != nil
name = "%s.%s" % [@service_name, name]
end
return ServiceProxy.new(@service_url, name)
end

def respond_to?(sym)
end

def call(*args)
postdata = {"method" => @service_name, "params" => args, "id" => "jsonrpc"}.to_json
respdata = RestClient.post @service_url, postdata
resp = JSON.parse respdata
if resp["error"] != nil
raise JSONRPCException.new, resp['error']
end
return resp['result']
end
end
</source>

== PHP ==

The [http://jsonrpcphp.org/ JSON-RPC PHP] library also makes it very easy to connect to Bitcoin. For example:

<source lang="php">
require_once 'jsonRPCClient.php';

$bitcoin = new jsonRPCClient('http://user:password@127.0.0.1:8332/');

echo "<pre>\n";
print_r($bitcoin->getinfo()); echo "\n";
echo "Received: ".$bitcoin->getreceivedbylabel("Your Address")."\n";
echo "</pre>";
</source>

=== Precision ===

Because PHP has no option to JSON decode to accurate decimal class, you should internally use GMP. Treat each number like a large int with 8 decimal places (this can be trimmed for display).

You will need to get a [https://github.com/genjix/bitcoin/tree/strrpc saner branch] and compile it. This treats every monetary value int64 8 decimal strings. So 1 BTC will be "100000000". Use PHP's GMP functions to manipulate these values accurately.

For converting between internal GMP numbers and display/user input, you can use these functions:
<source lang="php">
# converts a user supplied number to our internal representation
# 3.14 => "314000000"
# accepts strings, floats and ints as input
function numstr_to_internal($numstr)
{
return bcmul($numstr, pow(10, 8), 0);
}
# converts an internal number to an end user number for display as defined by precision
# 314100000 => "3.14"
# accepts GMP numbers, ints and strings as input
function internal_to_numstr($num, $precision=2)
{
$repr = gmp_strval($num);
$repr = bcdiv($repr, pow(10, 8), $precision);
# now tidy output...
# trim trailing 0s
$repr = rtrim($repr, '0');
# and a trailing . if it exists
$repr = rtrim($repr, '.');
return $repr;
}

$num_internal = numstr_to_internal("3.141");
echo "".$num_internal."";
$num_display = internal_to_numstr($num_internal);
echo "".$num_display."";
</source>

If you need to do a decimal division in GMP, then GMP only supports integer division + a remainder ([http://php.net/manual/en/function.gmp-div-qr.php gmp_div_qr]). The work-around for this, is to use the bcmath module:
<source lang="php">
$a = gmp_init("100");
$b = gmp_init("3");
echo "".bcdiv(gmp_strval($a), gmp_strval($b), 3)."";
</source>

Note that bcdiv uses strings.

See also: [http://php.net/manual/en/ref.gmp.php GMP] and [http://php.net/manual/en/ref.bc.php BC Math] manuals.

== Java ==

The easiest way to tell Java to use HTTP Basic authentication is to set a default Authenticator:

<source lang="java">
final String rpcuser ="...";
final String rpcpassword ="...";

Authenticator.setDefault(new Authenticator() {
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication (rpcuser, rpcpassword.toCharArray());
}
});
</source>

Once that is done, any JSON-RPC library for Java (or ordinary URL POSTs) may be used to communicate with the Bitcoin server.

== Perl ==

The JSON::RPC package from CPAN can be used to communicate with Bitcoin. You must set the client's credentials; for example:

<source lang="perl">
use JSON::RPC::Client;
use Data::Dumper;

my $client = new JSON::RPC::Client;

$client->ua->credentials(
'localhost:8332', 'jsonrpc', 'user' => 'password' # REPLACE WITH YOUR bitcoin.conf rpcuser/rpcpassword
);

my $uri = 'http://localhost:8332/';
my $obj = {
method => 'getinfo',
params => [],
};

my $res = $client->call( $uri, $obj );

if ($res){
if ($res->is_error) { print "Error : ", $res->error_message; }
else { print Dumper($res->result); }
} else {
print $client->status_line;
}
</source>

== .NET (C#) ==
The communication with rpc service can be achieved using the standard httprequest/response objects.
A library for serialising and deserialising Json will make your life a lot easier:

* JayRock for .NET 4.0
* Json.Net for .NET 2.0 and above

The following example uses Json.Net:

<source lang="csharp">
HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create("http://localhost.:8332");
webRequest.Credentials = new NetworkCredential("user", "pwd");
/// important, otherwise the service can't desirialse your request properly
webRequest.ContentType = "application/json-rpc";
webRequest.Method = "POST";

JObject joe = new JObject();
joe.Add(new JProperty("jsonrpc", "1.0"));
joe.Add(new JProperty("id", "1"));
joe.Add(new JProperty("method", Method));
// params is a collection values which the method requires..
if (Params.Keys.Count == 0)
{
joe.Add(new JProperty("params", new JArray()));
}
else
{
JArray props = new JArray();
// add the props in the reverse order!
for (int i = Params.Keys.Count - 1; i >= 0; i--)
{
.... // add the params
}
joe.Add(new JProperty("params", props));
}

// serialize json for the request
string s = JsonConvert.SerializeObject(joe);
byte[] byteArray = Encoding.UTF8.GetBytes(s);
webRequest.ContentLength = byteArray.Length;
Stream dataStream = webRequest.GetRequestStream();
dataStream.Write(byteArray, 0, byteArray.Length);
dataStream.Close();

WebResponse webResponse = webRequest.GetResponse();

... // deserialze the response
</source>

== Command line (cURL) ==

You can also send commands and see results using [http://curl.haxx.se/ cURL] or some other command-line HTTP-fetching utility; for example:

<source lang="bash">
curl --user user --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "getinfo", "params": [] }'
-H 'content-type: text/plain;' http://127.0.0.1:8332/
</source>

You will be prompted for your rpcpassword, and then will see something like:

<source lang="javascript">
{"result":{"balance":0.000000000000000,"blocks":59952,"connections":48,"proxy":"","generate":false,
"genproclimit":-1,"difficulty":16.61907875185736,"error":null,"id":"curltest"}
</source>

== See Also==

* [[Original_Bitcoin_client/API_Calls_list|API calls list]]
* [[Running Bitcoin]]

[[Category:Articles using content from the old wiki]]
[[Category:Technical]]
[[Category:Developer]]