readline

/*
 *  call-seq:
 *     ios.readline(sep_string=$/)   => string
 *  
 *  Reads a line as with <code>IO#gets</code>, but raises an
 *  <code>EOFError</code> on end of file.
 */

static VALUE
rb_io_readline(argc, argv, io)
    int argc;
    VALUE *argv;
    VALUE io;
{
    VALUE line = rb_io_gets_m(argc, argv, io);

    if (NIL_P(line)) {
        rb_eof_error();
    }
    return line;
}