SYNOPSIS
        int copy_file(string from, string to)

DESCRIPTION
        The efun copy_file() will copy the file <from> to the new name <to>.
        If <to> exists and is a directory, then <from> will be placed in that
        directory and keep its original name.
        
        You must have read permission for <from> and write permission for
        the target file to copy the file.
        
        On successful completion copy_file() will return 0. If any
        occurs, 1 is returned, or a runtime is generated.

EXAMPLE
        copy_file("/players/wizard/obj.c", "/players/wizard/newobj.c");

SEE ALSO
        mkdir(E), rmdir(E), rm(E), rename(E)