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Users & Groups Management HowTos

Learn all about users and groups on Linux and Unix like operating systems. Topic include user & group creations, permissions & ownership, access control, ACL, and more ( rss feed ).

Linux: Show All Members of a Group

I am a new Linux user and created couple of groups on server. I need to find out all members of a group called "ftponly". How do I list all members of a group on Linux or Unix-like systems?
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Unix Command To Change Password

I am a new Unix user at my university/school. In Unix, how do I change my password to safeguard and increase the security of my Unix account?
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Ubuntu Linux: Find Groups A User Belongs To

How do I find out in which groups Ubuntu Linux users belong to? How do I find out Ubuntu Linux group membership for a particular user named tom?
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I know how to display notice of a computer's ownership, to warn against unauthorized access, under Linux gnome desktop. How do I display similar message under Apple Mac OS X to remind authorized users of their consent to monitoring?
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Linux Upgrade Password Hashing Algorithm to SHA-512

The default algorithm for storing password hashes in /etc/shadow is MD5. I was told to use SHA-512 hashing algorithm. How do I set password hashing using the SHA-256 and SHA-512 under CentOS or Redhat Enterprise Linux 5.4?
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Linux / UNIX: Restrict Access To A Given Command

How do I restrict access to a given command for instance /opt/apps/start, to authorized users only under Linux / UNIX / BSD operating system?
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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?
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