Functions in the commands API:
commands.exec( command )
commands.execAsync( command )
commands.list()
commands.getBlockPosition()
commands.getBlockInfo( x, y, z )
commands.getBlockInfos( minx, miny, minz, maxx, maxy, maxz )

The commands API can also be used to invoke commands directly, like so:
commands.say( "Hello World" )
commands.give( "dan200", "minecraft:diamond", 64 )
This works with any command. Use "commands.async" instead of "commands" to execute asynchronously.

The commands API is only available on Command Computers.
Visit https://minecraft.wiki/w/Commands for documentation on all commands.