read

/*
 * See Zlib::GzipReader documentation for a description.
 */
static VALUE
rb_gzreader_read(argc, argv, obj)
    int argc;
    VALUE *argv;
    VALUE obj;
{
    struct gzfile *gz = get_gzfile(obj);
    VALUE vlen;
    int len;

    rb_scan_args(argc, argv, "01", &vlen);
    if (NIL_P(vlen)) {
        return gzfile_read_all(gz);
    }

    len = NUM2INT(vlen);
    if (len < 0) {
        rb_raise(rb_eArgError, "negative length %d given", len);
    }
    return gzfile_read(gz, len);
}