Some handy utility functions I came up with working with Minecraft craftscripts

craftscript_utils.js

/*
Some handy utility functions I came up with working with Minecraft craftscripts
*/

// exec
// performs a java exec by getting the java runtime by name

exec = function name(cmd){
    var cRuntime = java.lang.Class.forName("java.lang.Runtime");
    var mGetRuntime = cRuntime.getMethod("getRuntime");
    var rtsingleton = mGetRuntime.invoke(null);
    var process = rtsingleton.exec(cmd);    
    var stdInput = new java.io.BufferedReader(new java.io.InputStreamReader(process.getInputStream()));
    var stdError = new java.io.BufferedReader(new java.io.InputStreamReader(process.getErrorStream()));
}


// read a file

function read_file(path){ 
     var stream = new java.io.FileInputStream(new java.io.File(path)); 
     var fc = stream.getChannel(); 
     var bb = fc.map(java.nio.channels.FileChannel.MapMode.READ_ONLY, 0, fc.size()); 
     return java.nio.charset.Charset.defaultCharset().decode(bb).toString(); 
 } 

// load another js file
/*
Useful if you want to organise your craftscripts a bit. Copy and past load and read_file into the file where you call them

nb functions in the file you load must be declared this this

functionname = function name(attrs){}

and not

functionname(attrs){}

like add_command_block below - I dont know why - if you do I'd be interested to know

*/

function load(path){ 
     eval(String(read_file(path))) 
 } 


// adds a new command block
// messy but it works

add_command_block = function name(x, y, z, command){ 
    // creates a block
    var commandBlock = new BaseBlock(137);
    var pt = new Vector(x, y, z);
    session.rawSetBlock(pt, commandBlock);
    // reads it backs again
    var block = session.getBlock(pt);
    // the tags are immutable so gets its current tags
    var nbtdata = block.getNbtData()
    var tags = nbtdata.getValue();
    // clones them into a new set of tags but with command added
    var newTags = {}
    newTags["id"] = new StringTag("id", tags.get("id").getValue());
    newTags["Command"] = new StringTag("Command", command);
    newTags["x"] = new IntTag("x", tags.get("x").getValue());
    newTags["y"] = new IntTag("y", tags.get("y").getValue());
    newTags["z"] = new IntTag("x", tags.get("z").getValue());
    var newCompoundTag = new CompoundTag("", newTags);
    // replace tags with new ones
    block.setNbtData(newCompoundTag);
    // put block back
    session.setBlock(pt, block);
}