method

directory?

ruby latest stable - Class: File::Stat

directory?()

public

Returns true if the named file is a directory, or a symlink that points at a directory, and false otherwise.

file_name can be an IO object.

File.directory?(".")

static VALUE
rb_stat_d(VALUE obj)
{
    if (S_ISDIR(get_stat(obj)->st_mode)) return Qtrue;
    return Qfalse;
}