Getting group id linux

7 methods to list user groups in Linux? [SOLVED]

In operating systems, applications add their own users and groups to the system. From an administrative point of view, this makes it easier for users. Adding users to the application group is the easiest way to edit privileges. As a matter of fact, systems such as LDAP and Active Directory are also built on this method.

There are many methods of listing groups in Linux. In some methods, group information is accessed from the user, while in some methods, users are accessed from group information. We will tell you some of the most used methods with examples.

Method-1: Using groups command

When you run the groups command without any parameters, it lists the group information of the user who opened the terminal:

foc@fedora:~$ groups foc wheel

If you type a username after the group command, the groups belonging to that user are listed:

foc@fedora:~$ groups golinux golinux : golinux

In this method, groups are listed with user information.

Method-2: Using id command

Like the group command, the id command, when executed without parameters, lists the active user’s groups. But this time group id are also displayed:

foc@fedora:~$ id uid=1000(foc) gid=1000(foc) groups=1000(foc),10(wheel)

By typing the username after the id command, the groups belonging to that user are listed with their ids:

foc@fedora:~$ id golinux uid=1001(golinux) gid=1001(golinux) groups=1001(golinux)

As the user’s group information increases, the information displayed on the screen may not be understood. With the parameters of the ID command, the output can be made more understandable. For example, to list all group ids and names:

foc@fedora:~$ id -Gn golinux golinux

You can get help from the —help page for all its parameters:

foc@fedora:~$ id --help Usage: id [OPTION]. [USER]. Print user and group information for each specified USER, or (when USER omitted) for the current user. -a ignore, for compatibility with other versions -Z, --context print only the security context of the process -g, --group print only the effective group ID -G, --groups print all group IDs -n, --name print a name instead of a number, for -ugG -r, --real print the real ID instead of the effective ID, with -ugG -u, --user print only the effective user ID

Again in this method, groups are listed with their user information.

Method-3: Using getent command

The getent command pulls information from the group database. If there is no central system such as LDAP, Active Directory, it will pull from the local database.

You can pull groups by typing group after getent command:

foc@fedora:~$ getent group root:x:0: bin:x:1: . disk:x:6: lp:x:7: mem:x:8: kmem:x:9: wheel:x:10:foc cdrom:x:11: mail:x:12:

To list users in a group, you must type the group name:

foc@fedora:~$ getent group wheel wheel:x:10:foc

To list all groups in the system without details:

foc@fedora:~$ getent group | cut -d: -f1 root bin disk lp mem kmem wheel cdrom mail 

This method lists both groups and users in that group.

Method-4: Using /etc/group file

On Linux the group information is in the /etc/group file. If a user is added or removed from the group, this file changes.

When you view this file with file view commands like cat , it gives a complex output. To list group information, you can write it like this:

foc@fedora:~$ cut -d: -f1 /etc/group root bin . lp mem kmem wheel . tape video ftp 

For the total number of groups:

foc@fedora:~$ cat /etc/group | grep -c "" 82

Using awk command we can extract the group names from the /etc/group file using the colon ( : ) delimiter.

Method-5: Using compgen command

Another command you can use to list groups in Linux is compgen . You can list the groups in the system with the -g parameter:

[foc@rocky9 ~]$ compgen -g root bin wheel ftp lock audio users nobody foc 

Method-6: Using lid command

This command displays information about the specified group, including the GID, group password (if any), and members.

# lid -g nagios nagios(uid=1001) apache(uid=48) snmptt(uid=974)

Method-7: Using dscl command (On MacOS)

Using the dscl command on macOS. This command displays information about the specified group on macOS.

dscl . -read /Groups/groupname

Bonus Tip

If you want to list the groups of users logged into the system, you can use the following for loop:

[foc@rocky9 ~]$ for user in $(cat /etc/passwd | grep bash | awk -F: '');do groups $user; done root : root foc : foc wheel

Note: Bash was chosen as the default shell. If a different shell(zsh,sh etc) is used, it can be written after the grep command.

What is NEXT?

Summary

There is always an alternative on Linux. We have explained different ways to list groups in Linux for you. The commands and methods used may vary according to habits. You can use whichever method is faster and easier for you. Of course the choice is yours.

You can get help with the -h/—help parameter for each command. For more detailed information, you can also access the man page of the commands as in the example:

foc@fedora:~$ man id NAME id - print real and effective user and group IDs SYNOPSIS id [OPTION]. [USER]. .

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How to get group id from group name in Linux?

In Linux, user and group information is stored in the system’s user database, which is maintained by the operating system. Group IDs (GIDs) are assigned to each group and are used to control access to resources such as files and directories. Group names, on the other hand, are human-readable and make it easier to manage the groups and their members. In some cases, it may be necessary to convert between the two representations of a group, either from a group name to its corresponding GID, or from a GID to its corresponding group name.

Method 1: Using the getent Command

To get the group ID from the group name, you can use the getent command with the group option.

getent group group_name> | cut -d: -f3

This command will return the group ID of the group with the specified name.

To get the group name from the group ID, you can use the getent command with the group option and awk command to filter the output.

This command will return the group name of the group with the specified ID.

Here is a step-by-step breakdown of the commands:

1. To get the group ID from the group name, we use the getent command with the group option. This command retrieves the group information from the system’s group database.
2. We pipe the output of the getent command to the cut command using the pipe symbol ( | ). The cut command is used to extract a specific field from the output. In this case, we are extracting the third field, which is the group ID.
3. The -d option is used to specify the delimiter used in the output. In this case, the delimiter is a colon ( : ).
4. The -f option is used to specify the field number to extract. In this case, we are extracting the third field.
5. To get the group name from the group ID, we use the getent command with the group option. This command retrieves the group information from the system’s group database.
6. We pipe the output of the getent command to the awk command using the pipe symbol ( | ). The awk command is used to filter the output based on a specific condition.
7. The -F option is used to specify the field separator used in the output. In this case, the separator is a colon ( : ).
8. The $3 == condition is used to filter the output based on the third field, which is the group ID.
9. The print $1 command is used to print the first field, which is the group name.

These commands are useful for scripting and automation tasks where you need to get the group ID or group name programmatically.

Method 2: Using the id Command

To get the group ID from the group name, you can use the -g option of the id command. For example, to get the group ID of the group «sudo», you can run the following command:

This will output the group ID of the «sudo» group.

To get the group name from the group ID, you can use the -n option of the id command. For example, to get the group name of the group with ID 1001, you can run the following command:

This will output the name of the group with ID 1001.

You can also get a list of groups that a user belongs to by running the id command without any options. For example, to get the groups that the current user belongs to, you can run the following command:

This will output information about the user, including the user ID, group ID, and a list of groups that the user belongs to.

To get a list of all groups on the system, you can run the following command:

This will output a list of all groups on the system, including their names, group IDs, and a list of users that belong to each group.

That’s it! These are the basic commands that you can use to get the group ID from the group name and vice versa using the id command.

Method 3: Using the awk Command

To get the group id from group name in Linux using the awk command, follow these steps:

awk -F: 'group_name>") print $3>' /etc/group

1. Replace with the name of the group you want to get the group id for.
2. Press enter to run the command.
3. The group id for the specified group name will be displayed in the terminal.

To get the group name from group id in Linux using the awk command, follow these steps:

awk -F: 'group_id>") print $1>' /etc/group

1. Replace with the id of the group you want to get the group name for.
2. Press enter to run the command.
3. The group name for the specified group id will be displayed in the terminal.

• The -F: option is used to specify the delimiter as a colon.
• The if statement checks if the first field (group name) or the third field (group id) matches the input.
• The print statement prints the third field (group id) or the first field (group name) if the input matches.

Example: Suppose we want to get the group id for the group named sudo . We can run the following command:

This will output 27 , which is the group id for the sudo group.

Similarly, suppose we want to get the group name for the group id 1000 . We can run the following command:

This will output mygroup , which is the group name for the group id 1000 .

Method 4: Using the grep Command

To get group id from group name:

Step 1: Open the terminal and type the following command:

cat /etc/group | grep group_name>

Step 2: Replace with the actual name of the group you want to find the group id for.

Step 4: The output will be in the following format:

Step 5: The group id is the number between the colons.

To get group name from group id:

Step 1: Open the terminal and type the following command:

cat /etc/group | grep :group_id>:

Step 2: Replace with the actual id of the group you want to find the group name for.

Step 4: The output will be in the following format:

Step 5: The group name is the text before the first colon.

Examples:

To get group id from group name:

cat /etc/group | grep developers

The group id for the group «developers» is 1002.

To get group name from group id:

The group name for the group id 1002 is «developers».

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