The reboot command is used to restart a computer without turning the power off and then back on.
reboot's syntax is
If reboot is used when the system is not in runlevel 0 or 6 (i.e., the system is operating normally), then it invokes the shutdown command with its -r (i.e., reboot) option.
Perhaps reboot's most useful option is -f, which is used to force a reboot in those rare situations in which reboot by itself might not work, for example due to a corrupted system. The -i option tells reboot to shut down all network interfaces prior to rebooting.
Pressing the reset button (which is located on the exterior of many personal computers) has an effect similar to that of using reboot. In those rare situations in which the entire system crashes (i.e., ceases to function properly, if at all) and the command line (i.e., the all-text display mode) is no longer accessible or operable, then the only choice is to use the reset button or to turn the power off for a few minutes and then restart the computer.
The reboot command takes its name directly from the term boot, which means to start a computer, and ultimately from the word bootstrap, which was a strap attached to the top of a boot that was used by people to pull their boots on.
Created April 2, 2006.