visudo command – nixCraft

How to run sudo command without a password on a Linux or Unix

May 17, 2015April 18, 2017in BASH Shell, CentOS, Debian / Ubuntu, FreeBSD, Linux, Suse, UNIX last updated April 18, 2017

I‘m a new Unix system user. How do I use sudo command without a password on a Linux or Unix-like systems? I log in as tom@my-cloud-server-ip and disabled root login for ssh. After login, I need to run some commands as root user. I am the only sysadmin using my server. How do I run or execute sudo command without a password for a user named Tom under Debian/Ubuntu/CentOS Linux cloud server?

How To Add, Delete, and Grant Sudo Privileges to Users on a FreeBSD Server

December 2, 2014December 2, 2014in FreeBSD, UNIX, User Management last updated December 2, 2014

I‘m setting up a new FreeBSD server. I do not want to use a default root user who has full system access. How can I setup and grant sudo privileges to users on a FreeBSD VPS or server?

CentOS / Red Hat: Sudo Allows People In Group Admin To Run All Commands

August 18, 2009August 18, 2009in CentOS, Fedora Linux, Linux, RedHat and Friends, Security, Troubleshooting, Ubuntu Linux, User Management last updated August 18, 2009

I like the way Ubuntu Linux works – all people in admin groups should able to run all commands after running it via sudo “command-name”. How do I setup sudo under CentOS or Red Hat Enterprise Linux to allow all members of the ‘admin’ group to run all commands?

Sudo is Not Prompting For a Password When Re-executed Second Time

February 3, 2008May 2, 2012in BASH Shell, CentOS, Debian / Ubuntu, Fedora Linux, FreeBSD, HP-UX Unix, Linux, Mac OS X, Openbsd, RedHat and Friends, Security, Solaris-Unix last updated May 2, 2012

I use sudo to provide permissions and command execution rights to other users under UNIX and Linux operating systems. However, I noticed something strange about sudo. When executing sudo, it will prompt for the user’s password the first time, but sudo no longer requires a password anymore when re-executing it. Why? Is this is a security risk?

sudo: Sorry, you must have a tty to run sudo Error on a Linux and Unix

August 8, 2007October 20, 2015in BASH Shell, Linux, Troubleshooting, UNIX last updated October 20, 2015

I‘m trying to run the following command:

ssh user@box.example.com sudo command1 /path/to/file

But, an error is displayed follows:

sudo: sorry, you must have a tty to run sudo

How do I fix this problem on Linux or Unix based systems?