How to find/view all the members of a group in Linux

Now in Linux we have two types of groups

First you need to know the GID of the group of whoose members you want to query for
Syntax:

# grep "group_name" /etc/group
# grep dba /etc/group
dba:x:503:

Now grep that GID to get list of users under dba group

# grep 503 /etc/passwd
deepak:x:501:503::/home/deepak:/bin/bash
user:x:502:503::/home/user:/bin/bash
deep:x:503:503::/home/deep:/bin/bash

To do this we have a no. of methods
Method 1

# getent group dba
dba:x:503:deepak,deep,user,user1

Method 2

# grep dba /etc/group
dba:x:503:deepak,deep,user,user1

Method 3
Syntax

# groupmems -g "group_name" -l

# groupmems -g dba -l
deepak  deep  user  user1