unshadow

Utility provided by the John the Ripper project to obtain the traditional Unix password file if the system uses shadow passwords. More information: https://www.openwall.com/john/.

• Combine the /etc/shadow and /etc/passwd of the current system:

sudo unshadow /etc/passwd /etc/shadow

• Combine two arbitrary shadow and password files:

sudo unshadow path/to/passwd path/to/shadow