---
name: "checkapoppw"
section: "8"
platform: "linux"
package: "checkpw"
version: "1.02-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/checkapoppw"
---

# checkapoppw(8)

checks APOP password against the file ~/Maildir/.password

## NAME

checkapoppw - checks APOP password against the file *~/Maildir/.password*

## SYNOPSIS

**checkapoppw** *prog*

## DESCRIPTION

**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 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, **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.

## Compatible tools

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 variables.

## 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*.

## Process-state changes

Before invoking  *prog*, **checkapoppw** sets up *$USER*, *$HOME*, *$SHELL*, its supplementary groups, its gid, its uid, and its working directory.

## FILES

\~/Maildir/.password

## SEE ALSO

[checkpw(8)](/checkpw/8.md), [qmail-popup(8)](/qmail-popup/8.md), [qmail-pop3d(8)](/qmail-pop3d/8.md)

## AUTHOR

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