.TH checkpw 8
.SH NAME
checkpw - checks password against the file
.I ~/Maildir/.password
.SH SYNOPSIS
.B checkpw
.I prog
.SH DESCRIPTION
.B 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 file.

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,
.B checkpw
exits 1.
If 
.B checkpw
is misused, it may instead exit 2.
If there is a temporary problem checking the password,
.B checkpw
exits 111.

If the password is acceptable,
.B checkpw
runs  
.IR prog .

.I prog
consists of one or more arguments.

.SH Compatible tools
There are other tools that offer the same interface as 
.B checkpw

Note that these tools do not follow the 
.I getopt
interface.
Optional features are controlled through
(1) the tool name and (2) environment variables.

.SH The password database

.B checkpw
checks the password
against the content of the file
.I Maildir/.password
in the user's home directory corresponding to the login name.

.I Maildir
may be overidden through the environment variable
.IR $MAILDIR .
.SH Process-state changes
Before invoking 
.IR prog ,
.B checkpw
sets up
.IR $USER ,
.IR $HOME ,
.IR $SHELL ,
its supplementary groups,
its gid,
its uid,
and its working directory.

.SH FILES
~/Maildir/.password

.SH SEE ALSO
checkapoppw(8),
qmail-popup(8),
qmail-pop3d(8)

.SH AUTHOR
This manual page was written by Gerrit Pape <pape@smarden.org>, for the
Debian GNU/Linux system.