Page 33 - RHEL8 BOOK

The users and groups information maintained by the 4 data files are
Users database Files
 /etc/passwd
 /etc/shadow

The user has one primary group only, but he/she has no. of secondary groups. Each user has one primary
group but the primary group has no. of primary users.
The user always created with primary group.

/etc/passwd - Database file of users

User properties
 The information of each user created is stored in a separate line in the file /etc/passwd
 Each record has seven fields separated by a: as given: -
#grep ravi /etc/passwd
ravi:x:1000:1000:prog:/home/ravi:/bin/bash

User
User UID Comment Shell

Mask Home

Password GID Directory

/etc/shadow

 This file contains the encrypted userPasswords assigned by the password binary file
 Password’s are encrypted using SHA 512 default which can even be change etc/shadow

ravi: hjkadfhs8974uyh5jrt/ :13536:0:99999:7:::

User Name Minimum No of
No of Days Days to change

Since 1970 password

Encrypted

Password
Minimum No of

Days to change Warning
password Days

S. Pradhan
(MCA, MBA-IT, BCA, CCNA, MCSA 2012, RHCE, ETHICAL HACKING)
Email Id:-spradhan.iiht@gmail.com
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