> For the complete documentation index, see [llms.txt](https://joungkyun.gitbook.io/annyung-3-user-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://joungkyun.gitbook.io/annyung-3-user-guide/annyung3-package-catalog/annyung3-base-packages/pkg-base-shadow-utils.md).

# shadow-utils

## Description:

Utilities for managing accounts and shadow password files

## Changes on AnNyung:

1. [ISMS](http://isms.kisa.or.kr/kor/intro/intro01.jsp) 인증 지원
   * password 최소 길이 5자 => 8자로 상향
   * password 만료일을 99999일에서 90일로 하향
   * password 만료 예외 리스트 추가 (*/etc/login.defs.exception*)
   * [Shell login Control (with PAM)](/annyung-3-user-guide/chapter2/chapter2-2-pam-control.md) 문서 참조
2. pwconv/pwunconv -l 옵션 추가
   * *-l* 옵션으로 지정된 directory에 있는 passwd/shadow 파일 관리 가능

     ```bash
     [root@an3 ~]$ mkdir /var/tmp/etc
     [root@an3 ~]$ cp -af /etc/passwd /etc/shadow /var/tmp/etc
     [root@an3 ~]$ pwunconv -l /var/tmp/etc
     [root@an3 ~]$ pwconv -l /var/tmp/etc
     ```
   * *-l* 옵션을 지원하지 않는다는 메시지가 나오면, ***yum update***를 해 주십시오.

## Sub packages:


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://joungkyun.gitbook.io/annyung-3-user-guide/annyung3-package-catalog/annyung3-base-packages/pkg-base-shadow-utils.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.