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⭕ Share quick reference cheat sheet for developers.

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docs: add reference file for systemd 2025-07-03 18:52:41 +05:30			`---`
			`title: Systemd`
			`date: 02-07-2025`
			`icon: icon-systemd`
			`background: bg-[#00ADEF]`
			`tags:`
			`- systemd`
			`- linux`
			`categories:`
			`- Linux Command`
			`intro: \|`
docs: add refrence section 2025-07-03 19:31:04 +05:30			`systemd is the init system and service manager used by most modern Linux distributions.`
docs: add reference file for systemd 2025-07-03 18:52:41 +05:30			`plugins:`
			`- copyCode`
			`---`

			`## systemd Core Utilities{.cols-4}`

			`### systemd utility List {.col-span-4}`

			`\| Utility \| Description \|`
			`\| ------------------------------------- \| -------------------------------------------------------------- \|`
			\| [`systemctl`](#systemctl) \| Manages services (start, stop, restart, enable, disable, etc.) \|
			\| [`journalctl`](#journalctl) \| Views and filters logs collected by the systemd journal \|
			\| [`loginctl`](#loginctl) \| Manages user logins and sessions \|
			\| [`hostnamectl`](#hostnamectl) \| Sets or queries the hostname and related machine metadata \|
			\| [`timedatectl`](#timedatectl) \| Sets or queries the system date, time, and NTP settings \|
			\| [`systemd-analyze`](#systemd-analyze) \| Analyzes system boot-up performance \|
			\| [`systemd-cgtop`](#systemd-cgtop) \| Monitors control group resource usage in real time \|
			\| [`systemd-run`](#systemd-run) \| Runs a command as a transient service or scope \|
			\| [`resolvectl`](#resolvectl) \| Resolves domain names using the systemd-resolved service \|
			\| [`busctl`](#busctl) \| Interacts with the D-Bus message bus system \|

			`{.left-text}`

			`---`

			`## Utility Commands {.cols-4}`

fix: expected end of comment, got end of file 2025-07-11 16:04:50 +01:00			`### systemctl {#systemctl .col-span-2 .row-span-2}`
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			`#### systemctl - System Commands`

			`- Manage systemd units and control system services (start, stop, enable, etc.).`

			`\| Command \| Description \|`
			`\| --------------------- \| ------------------------------------------------------------------ \|`
			\| `systemctl halt` \| Stop all running software, leave the hardware powered on. \|
			\| `systemctl hibernate` \| Save contents of system memory to disk and power off the hardware. \|
			\| `systemctl poweroff` \| Halt and power off the system. \|
			\| `systemctl reboot` \| Reboot the system. \|

			`{.left-text}`

			`#### systemctl - Service Commands`

			`\| Command \| Description \|`
			`\| ----------------------------- \| -------------------------------------------- \|`
			\| `systemctl start <service>` \| Start a service immediately \|
			\| `systemctl stop <service>` \| Stop a running service \|
			\| `systemctl restart <service>` \| Restart a service \|
			\| `systemctl reload <service>` \| Reload service configuration without restart \|
			\| `systemctl enable <service>` \| Enable service to start at boot \|
			\| `systemctl disable <service>` \| Disable boot-time start \|
			\| `systemctl status <service>` \| Show current status and recent logs \|
			\| `systemctl mask <service>` \| Prevent service from being started \|
			\| `systemctl unmask <service>` \| Remove mask so it can start again \|
			\| `systemctl list-units` \| List active units \|
			\| `systemctl list-unit-files` \| List all unit files and their enabled state \|

			`{.left-text}`

fix: expected end of comment, got end of file 2025-07-11 16:04:50 +01:00			`### journalctl {#journalctl .col-span-2}`
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			`- Query and filter logs from the systemd journal.`

			`\| Command \| Description \|`
			`\| -------------------------- \| ----------------------------------------- \|`
			\| `journalctl` \| Show entire journal \|
			\| `journalctl -b` \| Show logs from current boot \|
			\| `journalctl --list-boots` \| List all boot sessions \|
			\| `journalctl -b -1` \| Logs from previous boot \|
			\| `journalctl -u <service>` \| Show logs for a specific unit/service \|
			\| `journalctl -n 100` \| Show the last 100 log entries \|
			\| `journalctl -f` \| Follow new log entries (tail -f style) \|
			\| `journalctl -p err..emerg` \| Show only error (and above) priority logs \|
			\| `journalctl --disk-usage` \| Show disk usage of journal \|
			\| `journalctl --since today` \| Show logs since today \|

			`{.left-text}`

fix: expected end of comment, got end of file 2025-07-11 16:04:50 +01:00			`### busctl {#busctl .col-span-2}`
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			`- Inspect and monitor D-Bus (Desktop Bus) for debugging or introspection.`

			`\| Command \| Description \|`
			`\| ------------------------------ \| -------------------------------------------------- \|`
			\| `busctl list` \| List all services/peers on the bus \|
			\| `busctl status [SERVICE\\|PID]` \| Show process info & credentials for service or PID \|
			\| `busctl monitor [SERVICE...]` \| Dump live message traffic, Ctrl+C to stop \|
			\| `busctl capture [SERVICE...]` \| Capture bus traffic to a pcap file \|
			\| `busctl tree [SERVICE...]` \| Show object tree exported by service(s) \|

			`{.left-text}`

fix: expected end of comment, got end of file 2025-07-11 16:04:50 +01:00			`### loginctl{#loginctl .col-span-2 .row-span-2}`
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			`- Manages user sessions and login-related settings.`

			`\| Command \| Description \|`
			`\| --------------------------------- \| ---------------------------------------------- \|`
			\| `loginctl list-sessions` \| List all active sessions \|
			\| `loginctl list-users` \| List logged-in users \|
			\| `loginctl user-status <UID>` \| Show all sessions & processes for user `<UID>` \|
			\| `loginctl session-status <ID>` \| Show detailed info and logs for session `<ID>` \|
			\| `loginctl show-session <ID>` \| Show machine-parsable properties of a session \|
			\| `loginctl terminate-session <ID>` \| End all processes in session `<ID>` \|
			\| `loginctl lock-session <ID>` \| Lock the specified session \|
			\| `loginctl unlock-session <ID>` \| Unlock the specified session \|

			`{.left-text}`

fix: expected end of comment, got end of file 2025-07-11 16:04:50 +01:00			`### systemd-analyze{#systemd-analyze .col-span-2}`
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			`- Analyze system boot performance and unit dependencies.`

			`\| Command \| Description \|`
			`\| --------------------------------- \| ------------------------------------- \|`
			\| `systemd-analyze` \| Show total boot time breakdown \|
			\| `systemd-analyze blame` \| List services ordered by startup time \|
			\| `systemd-analyze plot > boot.svg` \| Generate SVG visual of boot sequence \|

			`{.left-text}`

fix: expected end of comment, got end of file 2025-07-11 16:04:50 +01:00			`### systemd-cgtop{#systemd-cgtop .col-span-2}`
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			`- Real-time monitoring of resource usage by cgroups (CPU, memory, I/O).`

			`\| Command \| Description \|`
			`\| -------------------------- \| ---------------------------------- \|`
			\| `systemd-cgtop` \| Monitor top cgroups resource usage \|
			\| `systemd-cgtop -c` \| Sort cgroups by CPU usage \|
			\| `systemd-cgtop -d <delay>` \| Change refresh delay interval \|

			`{.left-text}`

fix: expected end of comment, got end of file 2025-07-11 16:04:50 +01:00			`### timedatectl{#timedatectl .col-span-2}`
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			`- Manage system date, time, timezone, and NTP synchronization.`

			`\| Command \| Description \|`
			`\| ----------------------------------- \| ------------------------------- \|`
			\| `timedatectl status` \| Show current date/time settings \|
			\| `timedatectl list-timezones` \| List all available timezones \|
			\| `timedatectl set-timezone <Zone>` \| Set system timezone \|
			\| `timedatectl set-time "YYYY-MM-DD"` \| Manually set date \|
			\| `timedatectl set-time "HH:MM:SS"` \| Manually set time \|
			\| `timedatectl set-ntp true` \| Enable NTP sync \|
			\| `timedatectl set-ntp false` \| Disable NTP sync \|

			`{.left-text}`

fix: expected end of comment, got end of file 2025-07-11 16:04:50 +01:00			`### resolvectl{#resolvectl .col-span-2}`
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			`- Interact with systemd-resolved DNS resolver service.`

			`\| Command \| Description \|`
			`\| -------------------------------------- \| ----------------------------------------------- \|`
			\| `resolvectl status` \| Show DNS configuration and link info \|
			\| `resolvectl query <hostname>` \| Resolve hostname via systemd-resolved \|
			\| `resolvectl dns <interface> <IP>` \| Set DNS server(s) for a specific interface \|
			\| `resolvectl domain <interface> <name>` \| Set search domain(s) for an interface \|
			\| `resolvectl flush-caches` \| Clear the DNS cache managed by systemd-resolved \|
			\| `resolvectl reset-statistics` \| Reset all DNS resolution statistics \|

			`{.left-text}`

fix: expected end of comment, got end of file 2025-07-11 16:04:50 +01:00			`### hostnamectl{#hostnamectl .col-span-4}`
docs: add reference file for systemd 2025-07-03 18:52:41 +05:30
			`- Query and set the system hostname (static, transient, pretty) and related metadata.`

			`#### ↓ Commands`

			`\| Command \| Description \|`
			`\| --------------------------------------------- \| ------------------------------------------------ \|`
			\| `hostnamectl status` \| Show current hostname & system info \|
			\| `hostnamectl hostname <NAME>` \| Set the static/transient/pretty hostname \|
			\| `hostnamectl set-hostname <NAME> --static` \| Set only the static hostname \|
			\| `hostnamectl set-hostname <NAME> --transient` \| Set only the transient hostname \|
			\| `hostnamectl set-hostname <NAME> --pretty` \| Set the pretty (user-friendly) hostname \|
			\| `hostnamectl set-chassis <TYPE>` \| Set chassis type (e.g., desktop, laptop, server) \|

			`{.left-text}`

			`#### ↓ Description`

			```markdown
			- Static - The permanent hostname stored in `/etc/hostname`. Used at boot time.
			`- Transient - Temporary hostname set at runtime (often by DHCP or manually). Lost on reboot.`
			`- Pretty - A user-friendly, display name (can include spaces and special characters).`
			```

			`{.left-text}`

fix: expected end of comment, got end of file 2025-07-11 16:04:50 +01:00			`### systemd-run{#systemd-run .col-span-4}`
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			`- Run a command as a transient systemd unit (service, scope, timer, etc.).`

			`\| Command \| Description \|`
			`\| -------------------------------------------------------- \| -------------------------------------------------- \|`
			\| `systemd-run <command>` \| Run command as a transient `.service` unit \|
			\| `systemd-run -p BlockIOWeight=10 updatedb` \| Run with a specific resource limit property \|
			\| `systemd-run -p MemoryMax=100M script.sh` \| Run a memory-hungry task with a memory usage limit \|
			\| `systemd-run --on-calendar='YYYY-MM-DD HH:MM' script.sh` \| Schedule script to run at a specific date and time \|
			\| `systemd-run -E VAR=value script.sh` \| Run a script with environment variables set \|

			`{.left-text}`

			`#### Types of systemd limits{.col-span-3}`

			```markdown
			`There are different kinds of limit that can be imposed:`

			`- CPU Limits`
			`- Memory Limits`
			`- I/O Limits`
			`- Task/Thread Limits`
			`- Security/Isolation`
			`- Execution/Environment`
			```

			`Example`

			```bash
			`systemd-run -p MemoryMax=100M -p CPUQuota=50% scriptFile.sh`
			```
docs: add refrence section 2025-07-03 19:31:04 +05:30
			`## Also See`

			`- [linux training academy](https://www.linuxtrainingacademy.com/systemd-cheat-sheet/)`
			`- [linux Audit Cheat Sheet](https://linux-audit.com/cheat-sheets/systemd/)`
			`- [RedHat Reference](https://www.redhat.com/en/blog/systemd-commands)`