Understanding the /etc/passwd File

1. How do I read etc passwd file?
2. What is in the etc passwd file?
3. How does etc passwd work?
4. How are passwords stored in etc passwd?
5. What is the use of ETC passwd file?
6. Why is etc passwd world readable?
7. What is the ETC Group file?
8. Does deleting a user also delete the user's home folder?
9. What is the difference between etc passwd and etc shadow file?
10. How does etc shadow work?
11. What are shadowed passwords?
12. What does ETC shadow file contains?

How do I read etc passwd file?

How To Read the "/etc/passwd" File

1. root: Account username.
2. x: Placeholder for password information. The password is obtained from the "/etc/shadow" file.
3. 0: User ID. Each user has a unique ID that identifies them on the system. ...
4. 0: Group ID. ...
5. root: Comment field. ...
6. /root: Home directory. ...
7. /bin/bash: User shell.

What is in the etc passwd file?

The /etc/passwd file contains the username, real name, identification information, and basic account information for each user. Each line in the file contains a database record; the record fields are separated by a colon (:).

How does etc passwd work?

/etc/passwd file stores essential information, which required during login. In other words, it stores user account information. The /etc/passwd is a plain text file. It contains a list of the system's accounts, giving for each account some useful information like user ID, group ID, home directory, shell, and more.

How are passwords stored in etc passwd?

In older Linux systems, the user's encrypted password was stored in the /etc/passwd file. On most modern systems, this field is set to x , and the user password is stored in the /etc/shadow file.

What is the use of ETC passwd file?

Traditionally, the /etc/passwd file is used to keep track of every registered user that has access to a system. The /etc/passwd file is a colon-separated file that contains the following information: User name. Encrypted password.

Why is etc passwd world readable?

In the old days, Unix-like OSes, including Linux, generally all kept the passwords in /etc/passwd. That file was world readable, and still is, because it contains information allowing mapping for example between numeric user IDs and user names.

What is the ETC Group file?

The /etc/group is a text file which defines the groups to which users belong under Linux and UNIX operating system. Under Unix / Linux multiple users can be categorized into groups. Unix file system permissions are organized into three classes, user, group, and others.

Does deleting a user also delete the user's home folder?

Force delete. Files in the user's home directory will be removed along with the home directory itself and the user's mail spool. Files located in other file systems will have to be searched for and deleted manually.

What is the difference between etc passwd and etc shadow file?

/etc/passwd file aims at user account details while /etc/shadow aims at the user's password details. the passwd file is world-readable. shadow file can only be read by the root account. The user's encrypted password can only be stored in /etc/shadow file.

How does etc shadow work?

The /etc/shadow file stores actual password in encrypted format and other passwords related information such as user name, last password change date, password expiration values, etc,. It's a text file and readable only by the root user and is therefore less of a security risk.

What are shadowed passwords?

Shadow passwords are an enhancement to login security on Unix systems. ... To test a password, a program encrypts the given password with the same "key" (salt) that was used to encrypt the password stored in the /etc/passwd file (the salt is always given as the first two characters of the password).

What does ETC shadow file contains?

/etc/shadow is a text file that contains information about the system's users' passwords. It is owned by user root and group shadow, and has 640 permissions .