Ls
如何檢查 /dev/sdt 的內容
我希望這不是一個大問題，但它最終可能會成為一個非常大的問題。
在某些情況下，我錯誤地在我的 27" iMac 上執行了這個命令：
sudo dd if=ubuntu-rescue.img of=/dev/sdt bs=1m之後，它給了我以下輸出：
233+1 records in 233+1 records out 244570112 bytes transferred in 2.275065 secs (107500277 bytes/sec)問題是，我不打算將 ubuntu-rescue.img 移動到
/dev/sdt. 哎呀！我現在正在嘗試弄清楚原始內容
/dev/sdt/是什麼（在我錯誤地將數據寫入該文件之前），以及是否有辦法檢查內容（刪除錯誤複製到那裡的磁碟映像，或者以某種方式將內容/dev/sdt恢復到其原始狀態）。另外，這個
dd命令會刪除之前的所有內容，還是只是向其中添加數據？我現在的主要問題是我不知道是什麼
/dev/sdt（它是文件嗎？驅動程序？安裝的驅動器？等等），所以我無法知道如何檢查造成的損壞。因此，當我執行此命令時，我需要了解我在看什麼：ls /dev以及如何檢查/訪問/讀取這些文件的內容。
我該怎麼辦？
For some further analysis, here are various output from various commands: Not a directory: $ cd /dev/sdt -bash: cd: /dev/sdt: Not a directory "Special Character" file $ file /dev/sdt /dev/sdt: character special Verbose ls output: $ ls -l /dev/sdt crw-rw-rw- 1 root wheel 0, 0 Dec 28 14:02 /dev/sdt "Size of" `/dev/sdt` $ du -sk /dev/sdt 0 /dev/sdt I ran the same commands from update #1 on a new Mac Mini (that didn't have its `/dev/sdt` drive tampered with `dd`, and it gave me the **exact same** output as I got on the the iMac after I ran the erroneous `dd` command. Does this mean that the /dev/sdt didn't "record" the contents of the dd transfer? Because the "size" of /dev/sdt displays as zero when I run `$ ls -l /dev/sdt`. Could it be that I got lucky and didn't do any permanent damage? Both of these commands: `$ du -sk /dev/sdt` and `$ ls -l /dev/sdt` give me the same results on the iMac (where the erroneous `dd` command was run) as it did on the untouched Mac Mini, showing that the data stored in `/dev/sdt` reads at 0 bytes. This makes me assume that this drive is a temporary system drive that is not meant to store data, because even after 240 MB of data was erroneously `dd`'d into it, it still reads at zero byes. Lastly, I was given a good idea (by user frostschutz) to run this command: dd if=/dev/sdt of=mystery bs=1M count=234 And compare the results of the "mystery" file with the contents of the ubuntu-resuce.img, and the output from that experimental `dd` left me with a file called "mystery" which was exactly zero bytes. So I am starting to feel confident that I didn't do any lasting damage, and that this drive is always empty. After listening to your very helpful discussions, and reading more on an [another (separate, but closely-related) question of mine here on U&L][1], I discovered that my question has already been asked, so for anyone wanting to read more on this discussion, you can look [here][2]. [1]: https://unix.stackexchange.com/questions/176304/why-does-the-unix-system-need-so-many-0-byte-drives-at-dev?noredirect=1#comment291323_176304 [2]: https://unix.stackexchange.com/questions/18239/understanding-dev-and-its-subdirs-and-files
我驚訝地發現我的 Mac Book Air確實有一個*/dev/sdt字元特殊設備。由於我無法理解它的本質，我查閱了我的Mac OS X for Unix Geeks副本。在第 60 頁，有/dev中所有條目的列表。確實提到了sdt ，並給出了令人費解的解釋：*
sdt 無證
這是全書唯一提到的。
因此，首先它不是儲存設備。其次，你不太可能用它來做任何事情。同時，我看不出任何真正的擔心理由。