If it is a string or a number then just prints it out.
If it is an object then the object will be printed in the form: "OBJ("+file_name((object)mix)+")"
If it is an array just "<ARRAY>" will be printed.
If the write() function is invoked by a command of an living but not interactive object and the given argument is a string then the lfun catch_tell() of the living will be invoked with the message as argument.
write("Hello world!\n");
Just print out a string.
write(this_player());This will print out something like "OBJ(std/player#1234)".
write( ({ "blub" }) );
Will print out "<ARRAY>".