gistfile1.lua

function is_url_in_buffer(buffer, url)
    lines = weechat.hdata_pointer(weechat.hdata_get('buffer'), buffer, 'own_lines')
    line = weechat.hdata_pointer(weechat.hdata_get('lines'), lines, 'first_line')
    hdata_line = weechat.hdata_get('line')
    hdata_line_data = weechat.hdata_get('line_data')
    while line do
        data = weechat.hdata_pointer(hdata_line, line, 'data')
        message = weechat.hdata_string(hdata_line_data, data, 'message')
        if string.find(message, url) then
            return true
        end
        line = weechat.hdata_move(hdata_line, line, 1)
        w.print(buffer, 'line'..line)
    end
    return false
end