how to view the content of a file in unix in ftp mode of DOS?

The GET command will print file contents to the console if you pass '-' as the output filename. E.g. ..

$ ftp some_site.com
...
ftp> get some_file.txt -
remote: some_file.txt
229 Extended Passive Mode Entered (|||36565|)
150 Opening BINARY mode data connection for php_errors.log (438 bytes)
...
... contents of some_file.txt will be printed here
...
226 Transfer complete
438 bytes received in 00:00 (116.51 KiB/s)
ftp>

You can not run VI and cat over a FTP client. You want to log into the unix box with SSH and then use VI and/or cat.

FTP is for file transfers only.

SSH allows for command line functions. Editing and viewing of files on the server.

You can view via this `root@kali:~$ ftp 10.10.101.129

Connected to 10.10.101.129.

...

230 Login successful.

Remote system type is UNIX.

Using binary mode to transfer files.

ftp> passive

Passive mode on.

ftp> ls

227 Entering Passive Mode (10,10,101,129,89,219).

150 Here comes the directory listing.

-rw-rw-r-- 1 1001 1001 141 Feb 23 2019 note

226 Directory send OK.

ftp> get note - #This displays the content in that file.

remote: note

227 Entering Passive Mode (10,10,101,129,89,219).

150 Opening BINARY mode data connection for note (141 bytes).

Jerry, I finally got a chance to update our internal social media platform (bookface.com).

Can you signup and like my doggo photos?

Thanks

226 Transfer complete.

141 bytes received in 0.00 secs (273.7481 kB/s) `

I don't think ftp allows for viewing files only file transfers, I think that some applications emulate a "view" of sorts by transfering part of a file using resumes and offsets to "view" the view able portion of a file. Downloading and viewing would be best if your client doesn't support viewing and your server resuming, it will be doing that anyways if it does.

Note: you should be able to enter the command "?" (no quotes) and get a full list of server supported commands. (see: http://www.cs.colostate.edu/helpdocs/ftp.html)

You should use SSH & putty on windows if you want access to a full terminal. http://www.chiark.greenend.org.uk/~sgtatham/putty/