NAME

unshadow – combines passwd and shadow files  

SYNOPSIS

unshadow password-file shadow-file  

DESCRIPTION

This manual page documents briefly the unshadow command, which is part of the john package. This manual page was written for the Debian GNU/Linux distribution because the original program does not have a manual page. john, better known as John the Ripper, is a tool to find weak passwords of users in a server.

The unshadow tool combines the passwd and shadow files so John can use them. You might need this since if you only used your shadow file, the GECOS information wouldn’t be used by the "single crack" mode, and also you wouldn’t be able to use the ‘-shells’ option. On a normal system you’ll need to run unshadow as root to be able to read the shadow file.  

Willie has over 15 years of experience in Linux system administration and DevOps. After managing infrastructure for startups and enterprises alike, he founded Command Linux to share the practical knowledge he wished he had when starting out. He oversees content strategy and contributes guides on server management, automation, and security.