Service & System

init

Process control initialization — change system runlevel.

Synopsis

syntax
init [OPTION]... [RUNLEVEL]

Examples

Reboot the system
sudo init 6
Halt the system
sudo init 0
Enter single-user rescue mode
sudo init 1

Common options

FlagDescription
0Halt the system
1Single-user mode
3Multi-user without GUI
5Multi-user with GUI
6Reboot

About init

The `init` command process control initialization — change system runlevel. Service and system commands manage daemons, scheduled tasks, system boot, and shutdown operations.

Modern Linux distributions use systemd for service management, though some still support SysVinit scripts. Understanding these commands is essential for deploying and maintaining production services.

The command accepts 5 commonly used flags shown above, though the full set of options is available in the man page (`man init`). The 3 examples on this page cover typical real-world usage patterns that you can copy and adapt for your own workflows.

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