Note

The FTP user, as discussed here, applies to anonymous FTP configurations and server setup.

Also, note that other Linux distributions might use a different default directory, such as /usr/local/ftp, for FTP files and anonymous users.

This entry follows the standard /etc/passwd enTRy: username, password, User ID, Group ID, comment field, home directory, and shell.

To learn more about /etc/password, see the section "The Password File" in Chapter 14, "Managing Users."

Each of the items in this entry is separated by colons. In the preceding example, you can see that the Ubuntu system hosting the server uses shadowed password because an x is present in the traditional password field. The shadow password system is important because it adds an additional level of security to Ubuntu; the shadow password system is normally installed during the Ubuntu installation.

The FTP server software uses this user account to assign permissions to users connecting to the server. By using a default shell of /bin/false for anonymous FTP users versus /bin/bash or some other standard, interactive shell, an anonymous FTP user, will be unable to log in as a regular user. /bin/false is not a shell, but a program usually assigned to an account that has been locked. As root inspection of the /etc/shadow file shows (see Listing 23.2), it is not possible to log in to this account, denoted by the * as the password.

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