checkapoppw - checks APOP password against the file ~/Maildir/.password
checkapoppw reads descriptor 3 through end of file and then closes
descriptor 3. There must be at most 512 bytes of data before end of
The information supplied on descriptor 3 is a login name terminated by
\0, a password terminated by \0, a timestamp terminated by \0, and
possibly more data. There are no other restrictions on the form of the
login name, password, and timestamp.
If the password is unacceptable, checkapoppw exits 1. If checkapoppw
is misused, it may instead exit 2. If there is a temporary problem
checking the password, checkapoppw exits 111.
If the password is acceptable, checkapoppw runs prog.
prog consists of one or more arguments.
There are other tools that offer the same interface as checkapoppw
Note that these tools do not follow the getopt interface. Optional
features are controlled through (1) the tool name and (2) environment
The password database
checkapoppw checks the APOP password against the content of the file
Maildir/.password (not encrypted) in the user’s home directory
corresponding to the login name.
Maildir may be overidden through the environment variable $MAILDIR.
Before invoking prog, checkapoppw sets up $USER, $HOME, $SHELL, its
supplementary groups, its gid, its uid, and its working directory.
checkpw(8), qmail-popup(8), qmail-pop3d(8)
This manual page was written by Gerrit Pape <email@example.com>, for the
Debian GNU/Linux system.