log( str )

Prints a string to the developer console, and saves it in the log file.
str The string to be logged

log( "Hello World!" )
log( tostring(managers.player:player_unit():key()) )

dohttpreq( url, callback(data, id), [progress_callback(id, bytes, total_bytes)] )

Performs a HTTP/S request to the specified URL. If successful, returns any retrieved data to the callback.
url The URL to attempt to retrieve data from.
returns An ID for the current HTTP request.

callback(data, id) A function to run when data is retrieved from the URL.
callback: data The data retrieved from the server, returned as a string.
callback: id The ID of the HTTP request.

progress_callback(id, bytes, total_bytes) A function to run when the HTTP request reports back its progress. It is optional.
progress_callback: id The ID of the HTTP request which is reporting its progress.
progress_callback: bytes The current amount of bytes which have been retrieved.
progress_callback: total_bytes The total amount of bytes which must be downloaded to complete the HTTP request.

dohttpreq( "http://google.com/", function(data, id)
    log( "Retrieved server data:\n" .. data )
end )

dohttpreq( "http://paydaymods.com/mybigfile.zip",
    function(data, id)
        log( "Retrieved server data:\n" .. data )
    function(id, bytes, total_bytes)
        log( id .. " downloaded " .. tostring(bytes) .. " / " .. tostring(total_bytes) .. " bytes")

unzip( zip_file, extract_dir )

Unzips the contents of a specified zip_file and places all contents in the directory extract_dir. Unzipping archives is slow and is not multithreaded, and should only be done during the menu state.
zip_file The zip archive which you wish to extract the contents of.
extract_dir The directory where the contents of ther archive zip_file should be extracted to.

local zip = "mods/base/downloads/goonmod.zip"
local mods_folder = "mods/"
unzip( zip, mods_folder )