This article explains the use of FTP commands: QUIT, USER, ABOR, ACCT, SYST, XDEL
All Serv-U versions
QUIT FTP command
This command ends a USER session and if file transfer is not in progress, the server closes the control connection. If file transfer is in progress, the connection will remain open so it can receive the response from the data transfer before the server closes it.
Note: An unexpected close on the control connection will cause the server to effectively respond as though an abort (
ABOR) and a logout (
QUIT) were issued.
USER FTP command
USER is followed by a text string identifying the user. The user identification is that which is required by the server for access to its file system. This command will normally be the first command transmitted by the user after the control connections are made. This command is usually followed by the
PASS (Password) command.
ABOR FTP command
ABOR command can be issued by the client to abort the previous FTP command. If the previous FTP command is still in progress or has already completed, the server will terminate its execution and close any associated data connection. This command does not cause the connection to close.
ACCT FTP command
ACCT command is used to provide an account name to the server. The account is not necessarily related to the
USER. A client may log in using their username and password, however, an account may be required for specific access to server resources.
SYST FTP command
A client can issue this command to the server to determine the operating system running on the server. Not all server responses are accurate in this regard, however, as some servers respond with the system they emulate or may not respond at all due to potential security risks.
XDEL FTP command
XDEL deletes the specified file on the server, and is a duplicate of the
DEL command. It is implemented because some firewalls assume that all FTP characters must be 4 characters in length.