Scripting
Bash
System Administration Patterns
403 User and Group Management Scripts

Introduction
Commands
- Help and Docs
  - Intro
  - man
  - help (shell builtin)
  - info
  - apropos
  - whatis
- Files and Paths
  - Intro
  - pwd
  - cd
  - ls
  - tree
  - mkdir
  - rmdir
  - touch
  - cp
  - mv
  - rm
  - cat
  - less
  - more
  - chmod
  - chown
  - stat
  - file
  - find
  - fd
  - locate
  - ripgrep (rg)
  - ln
  - readlink
  - realpath
  - basename
  - dirname
  - which
  - alias / unalias
  - install
  - df
  - du
  - bat
  - eza
  - sha256sum
  - base64
  - cmp
  - getfacl / setfacl
  - chattr / lsattr
  - xxd
  - strings
  - namei
  - umask
  - Watching the filesystem: inotify vs fanotify
- Archives and Compression
  - Intro
  - tar
  - gzip
  - xz
  - bzip2
  - zstd
  - zip
  - unzip
  - zcat
  - zgrep
- System Information
  - Intro
  - uname
  - hostname
  - hostnamectl
  - lsb_release
  - uptime
  - date
  - timedatectl
  - cal
  - whoami
  - id
  - who
  - w
  - last
  - env
  - free
  - lscpu
  - lsmem
  - lsusb
  - lsmod
  - hwinfo
  - Four Ways to Talk to the Kernel
  - CPU masks and lists: reading the kernel’s bitmaps
- Processes and Jobs
- System Monitoring
- Users and Groups
  - Intro
  - sudo
  - visudo
  - useradd
  - usermod
  - userdel
  - passwd
  - chage
  - groupadd
  - groupmod
  - groupdel
  - getent
  - su
  - sudo-rs
- Networking
  - Intro
  - ip
  - ss
  - ping
  - traceroute
  - mtr
  - dig
  - host
  - nslookup
  - doggo
  - resolvectl
  - curl
  - wget
  - ssh
  - scp
  - rsync
  - nc
  - tcpdump
  - nmap
  - openssl
  - nmcli
  - ufw
  - nft
  - iptables
  - ifconfig
  - netstat
  - ftp
  - telnet
  - ssh-keygen
  - ssh-copy-id
  - sftp
  - ethtool
  - firewall-cmd
  - ssh-agent / ssh-add
  - Certificate renewal audit (64-day and 45-day certificates)
  - poll vs epoll vs io_uring
- Scheduling
  - Intro
  - cron
  - crontab
  - anacron
  - at
- Logging
  - Intro
  - dmesg
  - logger
  - logrotate
- Hardware
- Storage and Filesystems
- Terminals and Multiplexers
  - Intro
  - tmux
  - screen
  - byobu
  - tmate
  - abduco
- Text and Pipes
  - Intro
  - grep
  - sed
  - awk
  - cut
  - sort
  - uniq
  - tr
  - head
  - tail
  - wc
  - tee
  - xargs
  - diff
  - comm
  - paste
  - column
  - jq
  - pv
- Packages
  - Intro
  - apt
  - dpkg
  - dnf
  - rpm
  - yum
  - snap
- Services and Runtime
- Shell Commands
  - Intro
  - echo
  - printf
  - history
  - type / command
  - export
  - time
  - pushd / popd / dirs
- Security in Shell Scripts
- Appendices
  - Intro
  - Ubuntu Cheatsheet
Editors
Scripting
- Bash

Table of contents

User and Group Management Scripts

User and Group Management Scripts

Updated

October 31, 2026

User and Group Management Scripts

Batch provisioning Linux user accounts with SSH public keys and standard secondary groups.

Monitoring and Alerting Scripts

Log Processing and Rotation