13.7 Abnormal Termination of Data Transfer
Abnormal termination of a data transfer is practically the only use of the Telnet protocol commands (NVT protocol) by FTP.
In Table 13.3, we can find the ABOR
command that is used for an abnormal termination of the previously executed command. It could happen that the server would sequentially process individual client commands one by one. In such a case, the ABOR
command would be processed after the completion of the previous command. But we would usually want to terminate the previous (running) command sooner, i.e., to process the command ABOR
immediately when the server receives it. This can be achieved as follows:
The client software is generally sensitive to some key sequence for abnormal termination, for example, Ctrl + C (graphical clients can have a single button for termination). After pressing Ctrl + C, the client would like the server to stop sending data into the data channel. The client accomplishes this with two actions:
- With the help...