SOURCE for SteamId to Steam Community ID converter

// ==UserScript==
// @name SteamId/Steam Community ID convert
// @namespace tag:URI
// @Description Convert SteamId to SteamCommunity Profile page and vice versa
// @include http://www.enemydown.co.uk/clanmembers.php*
// @include http://enemydown.co.uk/clanmembers.php*
// @include www.enemydown.co.uk/clanmembers.php*
// @include enemydown.co.uk/clanmembers.php*
// @include http://www.enemydown.co.uk/userprofile.php*
// @include http://enemydown.co.uk/userprofile.php*
// @include www.enemydown.co.uk/userprofile.php*
// @include enemydown.co.uk/userprofile.php*
// ==/UserScript==

//Object to handle long bigdecimal numbers.. //IGNORE UNTIL LINE 153
//+ Jonas Raoni Soares Silva
//@ http://jsfromhell.com/classes/bignumber [rev. #3]

BigNumber = function(n, p, r){
var o = this, i;
if(n instanceof BigNumber){
for(i in {precision: 0, roundType: 0, _sign: 0, _dec: 0}) o = n;
o._buffer = n._buffer.slice();
return;
}
o.precision = isNaN(p = Math.abs(p)) ? BigNumber.defaultPrecision : p;
o.roundType = isNaN(r = Math.abs(r)) ? BigNumber.defaultRoundType : r;
o._sign = (n += "").charAt(0) == "-";
o._dec = ((n = n.replace(/[^\d.]/g, "").split(".", 2))[0] = n[0].replace(/^0+/, "") || "0").length;
for(i = (n = o._buffer = (n.join("") || "0").split("")).length; i; n[--i] = +n);
o.round();
};
with({$: BigNumber, o: BigNumber.prototype}){
$.ROUND_HALF_EVEN = ($.ROUND_HALF_DOWN = ($.ROUND_HALF_UP = ($.ROUND_FLOOR = ($.ROUND_CEIL = ($.ROUND_DOWN = ($.ROUND_UP = 0) + 1) + 1) + 1) + 1) + 1) + 1;
$.defaultPrecision = 40;
$.defaultRoundType = $.ROUND_HALF_UP;
o.add = function(n){
if(this._sign != (n = new BigNumber(n))._sign)
return n._sign ^= 1, this.subtract(n);
var o = new BigNumber(this), a = o._buffer, b = n._buffer, la = o._dec,
lb = n._dec, n = Math.max(la, lb), i, r;
la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb, 1) : o._zeroes(a, -lb, 1));
i = (la = a.length) == (lb = b.length) ? a.length : ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb)).length;
for(r = 0; i; r = (a[--i] = a + b + r) / 10 >>> 0, a %= 10);
return r && ++n && a.unshift(r), o._dec = n, o.round();
};
o.subtract = function(n){
if(this._sign != (n = new BigNumber(n))._sign)
return n._sign ^= 1, this.add(n);
var o = new BigNumber(this), c = o.abs().compare(n.abs()) + 1, a = c ? o : n, b = c ? n : o, la = a._dec, lb = b._dec, d = la, i, j;
a = a._buffer, b = b._buffer, la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb, 1) : o._zeroes(a, -lb, 1));
for(i = (la = a.length) == (lb = b.length) ? a.length : ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb)).length; i;){
if(a[--i] < b){
for(j = i; j && !a[--j]; a[j] = 9);
--a[j], a += 10;
}
b = a - b[i];
}
return c || (o._sign = n._sign), o._dec = d, o._buffer = b, o.round();
};
o.multiply = function(n){
var o = new BigNumber(this), r = o._buffer.length >= (n = new BigNumber(n))._buffer.length, a = (r ? o : n)._buffer,
b = (r ? n : o)._buffer, la = a.length, lb = b.length, x = new BigNumber, i, j, s;
for(i = lb; i; r && s.unshift(r), x.set(x.add(new BigNumber(s.join("")))))
for(s = (new Array(lb - --i)).join("0").split(""), r = 0, j = la; j; r += a[--j] * b[i], s.unshift(r % 10), r = (r / 10) >>> 0);
return o._dec = ((r = la + lb - o._dec - n._dec) >= (j = (o._buffer = x._buffer).length) ? this._zeroes(o._buffer, r - j + 1, 1).length : j) - r, o.round();
};
o.divide = function(n){
if((n = new BigNumber(n)) == "0")
throw new Error("Division by 0");
else if(this == "0")
return new BigNumber;
var o = new BigNumber(this), a = o._buffer, b = n._buffer, la = a.length - o._dec,
lb = b.length - n._dec, r = new BigNumber, i = 0, j, s, last;
r._sign = o._sign != n._sign, r.precision = Math.max(o.precision, n.precision),
r._dec = +r._buffer.pop(), la != lb && o._zeroes(la > lb ? b : a, Math.abs(la - lb));
n._dec = b.length, b = n, b._sign = false, b = b.round();
for(n = new BigNumber; a[0] == "0"; a.shift());
out:
do{
for(n == "0" && (n._buffer = [], n._dec = 0), last = 0; i < a.length && n.compare(b) == -1; ++i){
if(last = i + 1 == a.length, n == "0" && a[i] == "0"){
if(r._dec == r._buffer.length && ++r._dec, r._buffer.push(0), last)
break out;
}
else if(n._buffer.push(a[i]), ++n._dec, (last && n.compare(b) == -1 && (r._dec == r._buffer.length && ++r._dec, 1)) || (last = 0))
do
r._buffer.push(0), n._buffer.push(0), ++n._dec;
while(n.compare(b) == -1);
}
if(n.compare(b) == -1 && !(last = 0))
do
last ? r._buffer.push(0) : last = 1, n._buffer.push(0), ++n._dec;
while(n.compare(b) == -1);
for(s = new BigNumber, j = 0; n.compare(y = s.add(b)) + 1 && ++j; s.set(y));
n.set(n.subtract(s)), !last && r._dec == r._buffer.length && ++r._dec, r._buffer.push(j);
}
while((i < a.length || n != "0") && (r._buffer.length - r._dec) <= r.precision);
return r.round();
};
o.mod = function(n){
return this.subtract(this.divide(n).intPart().multiply(n));
};
o.pow = function(n){
var o = new BigNumber(this), i;
if((n = (new BigNumber(n)).intPart()) == 0) return o.set(1);
for(i = Math.abs(n); --i; o.set(o.multiply(this)));
return n < 0 ? o.set((new BigNumber(1)).divide(o)) : o;
};
o.set = function(n){
return this.constructor(n), this;
};
o.compare = function(n){
var a = this, la = this._dec, b = new BigNumber(n), lb = b._dec, r = [-1, 1], i, l;
if(a._sign != b._sign)
return a._sign ? -1 : 1;
if(la != lb)
return r[(la > lb) ^ a._sign];
for(la = (a = a._buffer).length, lb = (b = b._buffer).length, i = -1, l = Math.min(la, lb); ++i < l;)
if(a[i] != b[i])
return r[(a[i] > b[i]) ^ a._sign];
return la != lb ? r[(la > lb) ^ a._sign] : 0;
};
o.negate = function(){
var n = new BigNumber(this); return n._sign ^= 1, n;
};
o.abs = function(){
var n = new BigNumber(this); return n._sign = 0, n;
};
o.intPart = function(){
return new BigNumber((this._sign ? "-" : "") + (this._buffer.slice(0, this._dec).join("") || "0"));
};
o.valueOf = o.toString = function(){
var o = this;
return (o._sign ? "-" : "") + (o._buffer.slice(0, o._dec).join("") || "0") + (o._dec != o._buffer.length ? "." + o._buffer.slice(o._dec).join("") : "");
};
o._zeroes = function(n, l, t){
var s = ["push", "unshift"][t || 0];
for(++l; --l; n(0));
return n;
};
o.round = function(){
if("_rounding" in this) return this;
var $ = BigNumber, r = this.roundType, b = this._buffer, d, p, n, x;
for(this._rounding = true; this._dec > 1 && !b[0]; --this._dec, b.shift());
for(d = this._dec, p = this.precision + d, n = b[p]; b.length > d && !b[b.length -1]; b.pop());
x = (this._sign ? "-" : "") + (p - d ? "0." + this._zeroes([], p - d - 1).join("") : "") + 1;
if(b.length > p){
n && (r == $.DOWN ? false : r == $.UP ? true : r == $.CEIL ? !this._sign
: r == $.FLOOR ? this._sign : r == $.HALF_UP ? n >= 5 : r == $.HALF_DOWN ? n > 5
: r == $.HALF_EVEN ? n >= 5 && b[p - 1] & 1 : false) && this.add(x);
b.splice(p, b.length - p);
}
return delete this._rounding, this;
};
}

//FOR DEBUGGING
if(unsafeWindow.console){
var GM_log = unsafeWindow.console.log;

}

var converted_ids = ""; //IDs that have already been converted, used to prevent endless loop if the same ID exists more than once on the page.
var document_html = document.body.innerHTML;
var all_steam_ids = new String(document.body.innerHTML.match(/STEAM_[0-9]:[0-9]:[0-9]+/gi)); //all matched steam IDs on the page

var start_pos = end_pos = count = 0; //indexes to parse steam IDs from all_steam_ids
var steam_id, parsed_id, authSrv;
if(all_steam_ids.search(",") == -1){ //if only one occurence of a steam ID is on the page
steam_id = all_steam_ids;
parsed_id = steam_id.substring(steam_id.lastIndexOf(":")+1);
document.body.innerHTML = document.body.innerHTML.replace(steam_id ,'<a href="http://steamcommunity.com/profiles/'+co ... am_id+'<\a>');
}
else{
while(end_pos != -1){
end_pos = all_steam_ids.indexOf(",",start_pos);
if(end_pos == -1)
steam_id = all_steam_ids.substring(start_pos, all_steam_ids.length);
else
steam_id = all_steam_ids.substring(start_pos, end_pos);
parsed_id = steam_id.substring(steam_id.lastIndexOf(":")+1);
authSrv = steam_id.substring(steam_id.indexOf(":")+1,steam_id.lastIndexOf(":"));
if(converted_ids.search(steam_id) != -1){ //ID has already been converted
start_pos = end_pos + 1;
continue;
}
document_html = replaceAll(document_html, steam_id ,'<a href="http://steamcommunity.com/profiles/'+co ... d,authSrv)+'" target="_blank">'+steam_id+'<\a>');
converted_ids += steam_id;
}
document.body.innerHTML = document_html;
}




function convertSteamId(steamID, authSrv){ //No fuckin idea why (new BigNumber((steamID * 2) + authSrv)).add("76561197960265728"); returns weird results o.0
if(authSrv == 1)
return (new BigNumber((steamID * 2) + 1)).add("76561197960265728");
else
return (new BigNumber(steamID * 2)).add("76561197960265728");
}

// Replaces all instances of the given substring.
function replaceAll(textToSearch, strTarget, strSubString){
var intIndexOfMatch = textToSearch.indexOf(strTarget); //find first occurence of steamid
var temp_text, final_text="";
var start_pos= 0;
while (intIndexOfMatch != -1){
temp_text = textToSearch.substring(start_pos, intIndexOfMatch + strTarget.length); //substring until the end of the first steamid occurence
temp_text = temp_text.replace(strTarget, strSubString);
final_text += temp_text;
start_pos = intIndexOfMatch + strTarget.length;
intIndexOfMatch = textToSearch.indexOf(strTarget, intIndexOfMatch + strSubString.length);
}
final_text += textToSearch.substr(start_pos);
return final_text;
}

So what are we suppose to do with this?

No idea. I tought maybe someone would like to get that so here it is!

Looks like a greasemonkey script.