checkpw - checks password against the file ~/Maildir/.password
checkpw 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, checkpw exits 1. If checkpw is
misused, it may instead exit 2. If there is a temporary problem
checking the password, checkpw exits 111.
If the password is acceptable, checkpw runs prog.
prog consists of one or more arguments.
There are other tools that offer the same interface as checkpw
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
checkpw checks the password against the content of the file
Maildir/.password in the user’s home directory corresponding to the
Maildir may be overidden through the environment variable $MAILDIR.
Before invoking prog, checkpw sets up $USER, $HOME, $SHELL, its
supplementary groups, its gid, its uid, and its working directory.
checkapoppw(8), qmail-popup(8), qmail-pop3d(8)
This manual page was written by Gerrit Pape <firstname.lastname@example.org>, for the
Debian GNU/Linux system.