Command: uptime (uptimec)
UPTIME is a 16 bit DOS utility that display system uptime by automati-
cally detecting when it was firstly booted. It replicates *NIX uptime,
one of the basic UNIX commands which allows you to quickly confirm how
long your system has been up and running since it was last rebooted or
powered on.
Syntax:
UPTIME [-h|-r]
Options:
uptime Displays the current system uptime.
-h Shows the help screen.
-r Forces resetting the counter. Useful if it is not automatically
detected properly during startup.
Comments:
UPTIME uses CMOS data area to retrieve current system date/time using the
RTC (Real Time Clock). Since CMOS area is persistent, it uses CMOS alarm
registers, to store when the system was first startedup. Almost no DOS
programs use alarm capabilities, but if so, running UPTIME, will over-
write them.
There are different approaches to UPTIME in DOS, such as UPTIME 7.02 by
Mark Aitchison. His approach is to get system boottime, by reading
NUL: file timestamp. Unfortunately, this approach is not working in
DOSBox and other emulators.
UPTIME(c) has been specially optimized to run on pure DOS enviroments,
no matter if the are on the top of physical machines, or virtual
machines. It is written using JWASM 2.12 beta, with x86 assembly using
DOS tiny memory model in order to keep it compact.
Examples:
See above:
uptime
shows (for example):
13:05:44 up 0 hour, 0 minute, 29 second, 1 user, load average:
0.00, 0.00, 0.00
a new uptime shows (for example):
13:08:04 up 0 hour, 2 minute, 49 second, 1 user, load average:
0.00, 0.00, 0.00
uptime -h Shows the help
uptime -r
shows
Uptime counter reseted to zero
a new uptime then shows:
13:10:01 up 0 hour, 0 minute, 43 second, 1 user, load average:
0.00, 0.00, 0.00
See also:
uptime (another uptime program)
Copyright © 2017 Javier Gutierrez Chamorro, help version 2023
W. Spiegl.
This file is derived from the FreeDOS Spec Command HOWTO.
See the file H2Cpying for copying conditions.