If you want to use sudo su - user without a password, you should (if you have the privileges) do the following on you sudoers file: Doing just this, won't get subsequent commands get run by , it will spawn a new shell. su - jtp su jtp. Create a new system group and assign these users to that system group so I can assign all permissions to single system group, I create separate entries for all these users and then assign permission (very lengthy task). (e)dit sudoers file again Sudoer is the functionality of the Linux system that can be used by an administrator to provide administrative access to a trusted regular user, without actually sharing the root user's password. But, a normal user can do mount as shown below using sudo. (I'm using pwd as an example; the specific command is not important.) The syntax usage of sudoers can be little tricky and complicated for complex use cases. >>> /etc/sudoers: syntax error near line 126 <<< For example, I want user deepak to be able to execute all commands inside /usr/bin except chown command. chown: missing operand Get Lost. But first let me highlight you the dos and dont's which you must follow when working with sudoers file. But again this is of not too much use when you are working on single server deployment. Both "su" and "sudo" allow to execute commands on behalf of other user. >>> /etc/sudoers: syntax error near line 126 <<< Options are: $ sudo -u ismail ls / Comments are "secondary citizens", they are only for clarifications and so. (Q)uit and save changes to sudoers file (DANGER!). if you do not have a user then you must, These are different from groups, as to use a system group you must use, >>> /etc/sudoers: syntax error near line 125 <<< To use the su command on a per-command basis, enter: su user -c command. The above command which you to another user, where you can run commands with that user. Let us understand how third column is used in sudoers file. How can I su to user and then sudo command without asking for password? The su command allows you to become another user. This is the default behaviour of sudoers. su (Switch User) command is used to run shell as another user. [sudo] password for deepak: Hence I will create a new User_Alias and add the usernames to this alias, Next assign the permission of commands to this alias. sudo -s eval 'whoami; whoami' Note: The other answers using sudo -s fail because the quotes are being passed on to bash and run as a single command so need to strip quotes with eval.eval is better explained is this SO answer. 3. In this example we want to provide sudo privilege to user "deepak" from my Linux server to be able to execute chown and chmod as root user Example to understand first field of sudoers file. So let's give one more try: So I hope the third column usage was clear. To switch to another user and adopt their environment, enter su - followed by the name of the user (for example, su - ted ). chmod: missing operand The usage of su implies the knowledge of the "other" user password except if invoked by root. This ISS trash deployment looks more like 2 feet than 2 inches per second, was it too fast or are these articles incorrect? The steps to add user to sudoers with proper syntax and different practical examples, about different alias, and executing sudo commands without password prompt. Save my name and email in this browser for the next time I comment. DESCRIPTION sudo allows a permitted user to execute a command as the superuser or another user, as specified in the sudoers file. Short answer: you will get a root shell. Sudo Command Examples. There is a concept of alias in sudoers which can keep your sudoers file organized and clean. The log_input and log_output parameters enable sudo to run a command in pseudo-tty and log all user input and all output sent to the screen receptively.. If we run sudo command without specifying username explicitly the current user account will be used. When you enter this example, the system will use the specified account to run the ls (list directory contents) command. In the above output, the 1st column is my real UID (uid) and the 2nd is my effective UID (euid). Super User is a question and answer site for computer enthusiasts and power users. Are there examples of finite-dimensional complex non-semisimple non-commutative symmetric Frobenius algebras? You must provide the list of commands, or scripts with full path separated by a command and whitespace character. Running Command As Another User with Su. Try 'chmod --help' for more information. Welcome on the site! If you are running as a normal non-root user, prefix the command with sudo as shown. We will add below content to our /etc/sudoers.d/custom, If deepak tries to call amit_script.sh, he is asked to "Get Lost". Observed on Debian Wheezy with htop: 'sudo su -' has a child of 'su -', and 'su -' has a child of '-su'. Here is how to do it –. An alternative using eval so avoiding use of a subshell:. What do you roll to sleep in a hidden spot? How can I update values based on the value from the previous day? In this tutorial I gave you a complete overview on best practices to use and modify sudoers file. SUDO_UID: Set to the uid of the user who invoked sudo. sudo -i -u user Example (with a command): sudo -i -u user whoami. To overwrite this you must use NOPASSWD in the sudoers file while adding the user permission in the below format (from our last example), So now user deepak can execute all the commands with sudo privilege without the need to enter password every time. State of the Stack: a new quarterly update on community and product, Podcast 320: Covid vaccine websites are frustrating. i do not have permission to edit sudoers file.. any other so that it should read password from somewhere so that automation of this can be done. how to give superuser permission in linux? If you set a root password when you installed the distribution, enter su. By default this will require you to provide your password again as a security measure. This article explains how to use the sudo command from end-user point of view. site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. 2. How to give user sudo access? The default sudoers file contain a lot of default entries and it may break if you do not modify the this file properly. Making statements based on opinion; back them up with references or personal experience. Example (print user's $HOME): sudo -i -u user echo \$HOME. The sudo command for Linux users. Now we have 100 servers and using some remote tool we are deploying sudoers list to all these 100 servers. What now? Lastly I hope the steps from the article to learn all about sudo privilege and sudoers file on Linux was helpful. It only takes a minute to sign up. These are some of the common questions user have when they start working with sudoers file. Add a user to the wheel group with the following command: usermod –aG wheel [username] Replace [username] with an actual username. Once you exit (eg., Ctrl-D) from 'sudo su -', the execution of sudo will end. For example, mount can only be done by root. The host section defines the host this stanza applies to. Automate super user login in a shell script with password hardcoding, Make sudo ask for password for different user, How do a transform simple object to have a concave shape, Voltage drop across opposite diodes in series. Sorry, user deepak is not allowed to execute '/bin/chown' as root on server.example.com. $ sudo visudo Then add the following configuration below the line “%sudo ALL=(ALL:ALL) ALL” as shown in the following screenshot. su –c [command] [other_user] The system will respond by asking you for the user password. You may need to log in as an administrator or use the su command. Notify me via e-mail if anyone answers my comment. The syntax is simple: user host = (user) command. If you want to use sudo su - user without a password, you should (if you have the privileges) do the following on you sudoers file: ALL = NOPASSWD: /bin/su - where: is you username :D (saumun89, i.e.) Linux: How can I run multiple wine versions in a multilib enviroment? After this, the administrative command would be executed the same way as by the root user. It should then ask for a password. If you have something like ALL=NOPASSWD:ALL, become: yes will use sudo -u root and this will work fine, but become_user: user will run sudo -u user and that Sorry, user deepak is not allowed to execute '/tmp/amit_script.sh' as root on server.example.com. The major difference between " su" and " sudo" is, the first compels you to share the root password to other users whereas " sudo" allows you to run commands without root passwords. Let's understand the usage of second column. [sudo] password for deepak: Normal users operate in limited privilege sessions to limit the scope of their influence on the entire system. It is very important to update sudoers correctly or else you may break the complete sudoers functionality. Both su and sudo are used to run commands with root permissions. from a script. But we know the command was executed successfully with sudo privilege. I hope we are clear on the dos and dont's before you work on sudoers file. How is a person residing abroad subject to US law? There is a particular syntax which must be followed while adding a user or new entry to the sudoers file. By clicking “Accept all cookies”, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Thanks for contributing an answer to Super User! $ sudo mount /dev/sda3 /mnt In one of our earlier articles, we discussed the 'sudo' command in detail.Towards the ends of that tutorial, there was a mention of another similar command 'su' in a small note. Basic Usage. Is there a more modern version of "Acme", as a common, generic company name? If you want to run another command from within the script as this other user, you should use something like: Will get things done, but would grant the permission to do anything as anyone. Replacement for “su user_with_sudo; sudo -s” for user without sudo-rights? Which languages have different words for "maternal uncle" and "paternal uncle"? The sudo command executes a command as another user but follows a set of rules about which users can execute which commands as which other users. i want a solution in which script automaticaaly reads password from somewhere. sudo allows a permitted user to execute a command as the superuser or another user, as specified by the security policy. So, let me know your suggestions and feedback using the comment section. Please explain, how does it work. Is US Congressional spending “borrowing” money in the name of the public? So now all the users part of MYADMINS alias group will have sudo privilege to execute chown as root user. What are sudo alias? Asking for help, clarification, or responding to other answers. If you want to read password from separate file, you can use, (Or whatever is the name of password file, containing password and single line break.). This incident will be reported. Log Sudo Command Input/Output. To run commands with administrative privileges as a regular user. e(x)it without saving changes to sudoers file >>> /etc/sudoers: syntax error near line 125 <<< For example, I have a scenario where I want to assign permission to execute same set of commands to a bunch of users. when the sudo su - user command gets executed,it asks for a password. The first column defines the user the command applies to. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. To achieve same sudo functionality to execute any single command user has to use ‘-c’ option of ‘su’. The administrator simply needs to add the regular user in the. Note: The backslash character ensures that the dollar sign reaches the target user's shell and is not interpreted in the calling user's shell. rev 2021.3.12.38768. Depending on how they are invoked the environment variables can change, causing different command results. We can also prevent users from executing a certain set of commands, scripts inside sudoers. Is there a link between democracy and economic prosperity? chmod: missing operand If the user is granted with sudo assess, the su command is invoked as root. And I am using command sudo su - user -c pwd.This command works when switching to one user… Then he tries to run the same script as sudo user, but sadly the output says he is not allowed to execute /tmp/amit_script.sh when he knows he was given privilege for this. This developer built a…, automate sudo su - user command without using expect or editing sudoers file. Below is the code snippit for using in python automation for running cmds under root privilege:: Below is the cmd example for running cmds under root privilege. The non root user account requires sudo privileges to do this, and this is normally setup by either adding the user or group to the /etc/sudoers file, or by adding the user to the wheel group. i dont have permission to do what u told earlier. To explain this you need to know what the programs do: su - The command su is used to switch to another user (s witch u ser), but you can also switch to the root user by invoking the command with no parameter.su asks you for the password of the user to switch, after typing the password you switched to the user's environment. SUDO_GID: Set to the gid of the user who invoked sudo. These can be used with scripting solutions to automate the command execution. I will create a new file under /etc/sudoers.d/ by the name "custom", you can use any name as per your requirement # touch /etc/sudoers.d/custom The fourth column should be easy to understand. sudo command_to_execute. So in such case I have below possible options, So the third option sounds easy and neat. It is always a good practice to leave the default, So you can create multiple files based on your teams or groups under, The first column defines what user or group this, If the word in this column is preceded by a, This column is most useful when you deploy a, For a desktop Ubuntu system, or a system where you don’t plan on deploying the, For single server deployment this section does not has much usage and can be left to default. When you login into a shell session via putty or moba where you have stored the login credentials for a non root account, simply add this command to be executed upon login in by putty or moba and it will switch your access to root right away. This is configured in a filed named /etc/sudoers. The sudo command allows you to run programs as another user, by default the root user. To explain a little better, why sudo su user -c command might work without a password while sudo -u user command won't, could have to do with sudoers configuration. Not in a comment, insert it into your answers. You can do that by running visudo, then changing the line that looks like: However if it's just for one script, it would be more secure to restrict passwordless access to only that script, and remove the (ALL), so they can only run it as root, not any user , e.g. It is an linux/unix command which is used by system administrator to give privileges to set of users as root for a given commands. The basic su command looks like below: su - username . Run man 5 sudoers to see all the details in the sudoers man page. It is similar to a variable which we use in scripts and codes. Configuring sudo command and the difference between " su" & " sudo" in Linux distributions is discussed in this article. deepak is not allowed to run sudo on server. To switch users before running many commands, enter: su user The root user is basically equivalent to the administrator user on Windows – the root user has maximum permissions and can do anything to the system. How do we add user to sudoers file? Long answer: it is different from doing 'su -' within a root shell. In this case, the user (for example aaronk) who will switch to another user account (for example postgres) should be in the sudoers file or in the sudo group to be able to invoke the sudo command. Try 'chown --help' for more information. This account doesn't have any restrictions that are present to normal users. Please note that you should protect your script from read access from unauthorized users. the script should read password from that file. echo "PASSWORD" | sudo -S su - && sudo su, Alternately you can use python pudo package: https://pypi.org/project/pudo/1.0.0/. Now these users are from different system groups. So here we have allowed all the commands under /usr/bin/* but have added a NOT (!) $ su -c apt-get install vlc. 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I am at beginner level and I need to use sudo su - and pwd in one command line in script for two different users. In the following example, sysadmin has allowed user john to restart apache server. The invoking user's real (not effective) user ID is used to determine the user name with which to query the security policy.sudo supports a plugin architecture for security policies and input/output logging. Replace user with the name of the account which you'd like to run the command as, and command with the command you need to run as another user. The third value is set in parentheses and defines what user or users the user in the first column can execute a command as. Create Custom Sudo Log File 5. i want a solution in which script automaticaaly reads password from somewhere. To switch to the root user on Ubuntu-based distributions, enter sudo su in the command terminal. What is the point in delaying the signing of legislation that the President supports? To fully explain the syntax of /etc/sudoers, we will use a sample rule and break down each column: So now that we know about the basic syntax of sudoers file, let us go ahead and add some users to sudoers file with privilege to execute few commands as root user, In this example we want to provide sudo privilege to user "deepak" from my Linux server to be able to execute chown and chmod as root user, I will create a new file under /etc/sudoers.d/ by the name "custom", you can use any name as per your requirement, Add the below content in this file using visudo, Next try to login as deepak user and execute chown as sudo, So the command prompts for password and the execution is successful. You can add multiple commands in the similar format to block the sudo access for these provided commands for respective user or group, As expected, user deepak is allowed to use chmod, But execution of chown is denied as defined in our configuration, By default you may have observed that, every time user tries to execute a command with sudo privilege, they are prompted for user password. Beginner Guide to sudo Command in Linux | Best Sudo command example sudo is abbreviated as superuser do. In Redhat/CentOS, the wheel group controls sudo users. You can choose to use wildcard ALL or provide the hostname of your host, either should be fine. DESCRIPTION. In production environment, sudoers file are handled very cautiously. This command switches to the new user and load their environment. SUDO_COMMAND: Set to the command run by sudo. Now our of these 100 servers we want user deepak to be allowed to use chown only on the host with hostname "server" so we will use, Now the same sudoers script will be deployed to 100 servers but user deepak will be allowed use chown with sudo only on server. The best answers are voted up and rise to the top, Super User works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us. i have the permission to store password in a file. Try 'chmod --help' for more information. The (user) section defines the user to run the command as, while the command section defines the command itself. Once the sudo access is provided to your account in /etc/sudoers, you can pass any root command as an argument to the sudo command. After hitting enter user will be prompted for password and obviously it’s for root password because we’re using ‘su’ command. What is the syntax used by sudoers file? You can ignore the "missing operand" error, since I have not used proper command syntax, the command is throwing error. Changing date on Ubuntu without sudo privilages, Accidentally change sudo user to /bin/false. SUDO_PROMPT: Used as the default password prompt: SUDO_COMMAND: Set to the command run by sudo: SUDO_USER: Set to the login of the user who invoked sudo: SUDO_UID: Set to the uid of the user who invoked sudo: SUDO_GID Example: su - jtp. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. is the user you want to change to; Then put into the script: sudo /bin/su - [centos@localhost ~]$ sudo --help sudo - execute a command as another user usage: sudo -h | -K | -k | -V usage: sudo -v [-AknS] [-g group] [-h host] [-p prompt] [-u user] usage: sudo -l [-AknS] [-g group] [-h host] [-p prompt] [-U user] [-u user] [command] usage: sudo [-AbEHknPS] [-r role] [-t type] [-C num] [-g group] [-h host] [-p prompt] [-T timeout] [-u user] [VAR=value] [-i|-s] [] usage: sudo -e [-AknS] … For example, to update the system in Ubuntu & Debian as a regular user run The super user do, or sudo command on the other hand instead allows you to run a command as root from your current user. su jtp. What is the mathematical meaning of the plus sign (+) in chemical reaction equations? 1. In this tutorial I will give you a detailed overview on sudo privileges and share the proper way to add user to sudoers file. To learn more, see our tips on writing great answers. Here in the below syntax, all the ALIAS_NAME must be provided in UPPERCASE letters or you will get syntax error. SUDO_PS1: If set, PS1 will be set to its value. How to travel to this tower with a gorgeous view toward Mount Fuji? Why is my neutral wire connected to a breaker? ; sudo - sudo is meant to run a single command with root privileges. USER: Set to the target user (root unless the -u option is specified) VISUAL We will discuss about those syntax later in this article. The problem is, deepak is trying to run amit's script so he must use "sudo -u amit" to be able to execute amit's script as amit user. In this example the root user adds user1 to the wheel group, which is defined in the /etc/sudoers configuration … Look at the above snapshot, with the command "su - jtp" current shell environment is /home/jtp and user is also jtp. Running sudo su - and then typing the user password has the same effect the same as running su - and typing the root password. This tutorial assumes that you already have a system user or group for which you wish to assign sudo privilege. The su command. In -s or -H mode (or if sudo was configured with the --enable-shell-sets-home option), set to home directory of the target user. Then the user would be asked to enter their own password depending upon the configuration.