/*
 *  call-seq:
 *     ios.lineno    => integer
 *  
 *  Returns the current line number in <em>ios</em>. The stream must be
 *  opened for reading. <code>lineno</code> counts the number of times
 *  <code>gets</code> is called, rather than the number of newlines
 *  encountered. The two values will differ if <code>gets</code> is
 *  called with a separator other than newline. See also the
 *  <code>$.</code> variable.
 *     
 *     f = File.new("testfile")
 *     f.lineno   #=> 0
 *     f.gets     #=> "This is line one\n"
 *     f.lineno   #=> 1
 *     f.gets     #=> "This is line two\n"
 *     f.lineno   #=> 2
 */

static VALUE
rb_io_lineno(io)
    VALUE io;
{
    OpenFile *fptr;

    GetOpenFile(io, fptr);
    rb_io_check_readable(fptr);
    return INT2NUM(fptr->lineno);
}