FTP Replies

Each time the user-PI sends a command to the server-PI over the control connection, the server sends back a reply. FTP replies serve three main purposes:

  • They serve as confirmation that the server received a command.

  • They tell the user device whether or not the command was accepted, and if an error occurred, what it was.

  • They communicate various types of information to the user of the session, such as the status of a transfer.

Advantages of Using Both Text and Numeric Replies

For a human user, a string of reply text would be sufficient to satisfy the requirements just mentioned, and FTP replies do include descriptive text. But having only a text string would make it difficult or impossible for FTP software on the client side to interpret ...

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