我正在使用此命令来镜像服务器上的目录树：
wget -m -e robots=off --no-parent --reject-regex index.html --reject-regex aaa --no-verbose --timestamp https://example.com/folders/
“folders”目录有一个.htaccess包含指令的文件Options +Indexes。
但是，对于每个目录，它都会创建一个index.html文件，反映服务器生成的显示该目录索引的页面。
由于它实际上不是一个文件，因此它没有修改时间戳标头。我想阻止 wget 创建该index.html文件。使用--reject-regex index.html不行。
我一直在尝试使用 wget 镜像服务器上的目录，然后仅使用较新的文件更新下载的树。本地机器运行的是MacOS 12.6.3；服务器是 CloudLinux，版本 6。
该服务器是半私有的，这意味着它没有密码保护，但不做广告，并且有无机器人建议。
我想使用比设置 rsync （ssh 密钥等）更简单的东西。我在 Unix SE 网站上找到的建议似乎是实现此目的的简单方法。
所以我运行了这个命令：
wget -m -e robots=off https://example.com/folders
（“文件夹”目录Options +Indexes中有一个指令.htaccess）
这就创建了最初的目标。一切都下载得很好，并在我的本地计算机上创建了初始“文件夹”目录树，所有文件都完好无损。
然后，我在最初下载的服务器上的树中创建了一个新文件，然后尝试运行它以查看它是否会获取新文件：
wget -m -e robots=off --timestamp https://example.com/folders
但我收到这个错误：
Cannot write to ‘example.com/folders’ (Success).
完整输出：
--2023-12-24 05:29:07-- https://example.com/folders
Resolving example.com (example.com)... 123.456.789.123
Connecting to example.com (example.com)|123.456.789.123|:443... connected.
HTTP request sent, awaiting response... 301 Moved Permanently
Location: https://example.com/folders/ [following]
--2023-12-24 05:29:07-- https://example.com/folders/
Reusing existing connection to example.com:443.
HTTP request sent, awaiting response... 200 OK
Length: 3671 (3.6K) [text/html]
example.com/folders: Is a directory
Cannot write to ‘example.com/folders’ (Success).
我检查了提到的文件夹的权限，它们都很好。
搜索“无法写入”消息产生了一堆与我的用例无关的结果。
按照这里的指南：
https://wiki.gnuradio.org/index.php/InstallingGR#Ubuntu_PPA_Installation
我尝试安装：
sudo add-apt-repository ppa:gnuradio/gnuradio-releases
sudo add-apt-repository ppa:gnuradio/gnuradio-master
sudo add-apt-repository ppa:gnuradio/gnuradio-releases-3.7
sudo apt-get update
sudo apt install gnuradio
我的输出：
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
gnuradio : Depends: libgnuradio-analog (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-audio (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-blocks (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-channels (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-digital (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-dtv (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-fec (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-fft (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-filter (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-qtgui (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-runtime (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-trellis (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-uhd (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-video-sdl (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-vocoder (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-wavelet (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Depends: libgnuradio-zeromq (>= 3.9.0.0git~master~13593~bionic) but it is not going to be installed
Recommends: python3-qwt-qt5 but it is not installable
E: Unable to correct problems, you have held broken packages.
如果我使用其中一个错误包沿着依赖链上升，我最终得到：
sudo apt-get install libgnuradio-runtime
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
libgnuradio-runtime : Depends: libvolk2.2 (>= 2.2.0) but it is not installable
E: Unable to correct problems, you have held broken packages.
最后：
sudo apt-get install libvolk2.2
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package libvolk2.2 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'libvolk2.2' has no installation candidate
查找 libvolk2.2 表明它位于 Debian 的 sid（不稳定）存储库中。但是，当我搜索有关安装 gnuradio 的信息时，我没有找到任何有关必须使用 sid 存储库的信息。如果是这样的话，我使用的指南似乎也会提到这一点。
因此，在使用 sid 存储库并冒着损坏的风险之前，我想看看是否还有其他一些我看不到的东西是需要的。
非常感谢您的帮助。
帮助将不胜感激。
[编辑] 还想提一下，这是 18.04 的全新安装，自动软件更新程序 AFAICT 的所有内容都是最新的。