os: accounts and privileges and commands

Author: practicalli-johnny

CHANGELOG.md

@@ -24,6 +24,7 @@
 - os: archive commands in file systems page
 - os: network commands page and examples
 - ci: github release from tag in practicalli workflows
+- os: accounts and privileges commands
 
 ### Changed
 

docs/os/command-line/commands/accounts-permissions.md

@@ -0,0 +1,82 @@
+# Accounts and Permissions
+
+Linux file system access is based on user account and group account membership.
+
+Read, Write and eXecute authorisation is defined with respect to the user (u), group (g) and all accounts (a)
+
+`whoami` shows the currently-logged in user account name.
+
+
+## Elevated privileges
+
+su switch to another user account, allowing different access permissions for the file system.  `su` is most commonly used to switch to the root user account.
+
+```shell
+su -
+```
+
+The operating system prompts for the account password that is being accessed.
+
+`sudo` temporarily elevates privileges to that of the root account, allowing access to files and commands that would otherwise be declined.
+
+For example, run the Debian Linux apt tool to update software versions.
+
+```shell
+sudo apt upgrade
+```
+
+
+## Change access permissions
+
+`chmod` changes access permissions of files or directories: chmod [options] [permission] [file-or-directory]
+
+Set owner access to read, write and access directories.
+
+```shell
+chmod u+rwX ~/projects
+```
+
+Set permissions literally:
+
+```shell
+chmod -rwx---r-– file.txt
+```
+
+The second, third and fourth position sets permission for the owner.  The next three the group and last three any other user.
+
+!!! INFO "Directory and file permissions"
+    read (r), write (w), and execute (x)
+
+    owner (u), a group (g), or other (o) accounts
+
+
+
+## Change ownership
+
+`chown` changes ownership of files, directories or symbolic links: chown [options] newowner:newgroup file1 file2
+
+Assign a user as the new owner of an item. Leave the group name empty to set the same as the user account.
+
+```shell
+chown practicalli ~/projects
+```
+
+Omit user account name to make all group members the owner
+
+
+```shell
+chown :hackers ~/projects
+```
+
+
+## Account management
+
+useradd creates a new account or update groups assigned to a user: useradd [options] new_username
+
+By default, the useradd command doesn’t prompt you to give the new user a password. You can add or change it manually later with the passwd command:
+
+passwd new_username
+
+userdel deletes a given account name and requires [elevated privileges](#elevated-privileges)
+
+To set up a password and other details during the account creation process, use the adduser command instead.

mkdocs.yml

@@ -194,6 +194,7 @@ nav:
           - Commands:
               - os/command-line/commands/index.md
               - File system: os/command-line/commands/file-system.md
+              - Accounts & permissions: os/command-line/commands/accounts-permissions.md
               - Scheduled tasks: os/command-line/commands/cron.md
       - Linux:
           - Overview: os/linux/index.md