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Would this be possible in any operation system?
Makaveli2007




msg:3732852
 11:22 pm on Aug 27, 2008 (gmt 0)

Hi guys,

I know absolutely nothing about Unix, etc. to be honest, but I was wondering if this would be possible in any known operating system (it's more of a technical/curiosity question to be honest):

Create a program that copies the time from the operating system and continues to run it's unique clock (on an administrator account that other accounts wouldn't have access to). The program/application would simply be a clock (which other than the time the computer is turned on runs independently from the computer time).

Use a line of code that would say something like "if comptime < applicationtime then shutdown". So in other words if a user tries to turn back the clock of the computer the computer gets shut down.

I bet this must seem like a silly question, because one could probably simply disallow any non-admin account to change the clock, but I'm wondering if this would work, too.

been looking too much into parental control/time restriction software recently, I guess lol

 

Makaveli2007




msg:3732861
 11:38 pm on Aug 27, 2008 (gmt 0)

I assume the problem with this is that one could simply use the task manager (or the equivalent of it in another operation system) to delete an application like that, correct?lol

mcavic




msg:3732862
 11:39 pm on Aug 27, 2008 (gmt 0)

Yes, you could write a program that would check the time every 15 seconds or so, and then if it sees a timestamp that differs from the last one by more than 2 minutes, shut down, or just synchronize the clock. In Unix/Linux, synchronizing is easy - once you've installed and configured ntpd, just run ntpdate, and it'll synchronize immediately.

But normally you would just set the OS so that it won't allow normal users to change the clock in the first place. That's the default in Unix/Linux. It's not recommended to let anyone set the clock incorrectly, because it can confuse applications if the time jumps.

Makaveli2007




msg:3733450
 1:48 pm on Aug 28, 2008 (gmt 0)

Unfortunately, I'm using windows not unix/linux..I know this isn't a windows forum - sorry..but at least I do understand, now why people dislike windows so much lol. In Win XP it's apparently not possible to keep other accounts from changing the time of the system (I asked a few buddies who know more about this than me and couldnt find a way+were surprised at this).

Still, I was interested if that idea/such an application would work (on whatever OS). But wouldnt it be easy for even a restricted user to simply use the taskmanager (or the equivalent of it in another OS) to simply cancel the application that's running?

I assume simply making sure the clock synchronizes every few seconds would not be an effective solution, because the computer would do too much work, right?lol

tangor




msg:3733478
 2:12 pm on Aug 28, 2008 (gmt 0)

In Windows set up a profile that disables (hides) all clock functions from the user (non-admin accounts). Can't change it if they can't find it.

tangor




msg:3733486
 2:17 pm on Aug 28, 2008 (gmt 0)

Sorry... should have added the following:

Hide the Clock with the Group Policy Editor in XP Pro or Vista:

open the group policy editor
Start\Run type gpedit.msc

Move through the left pane to:
User Configuration\Administrative Templates\Start Menu and Taskbar\

At right find the key: Remove Clock from the system notification area double click and select enable

vincevincevince




msg:3733493
 2:26 pm on Aug 28, 2008 (gmt 0)

Just a suggestion - you could pick up the current time from a remote server instead - if this parental control over surfing time then there's no way they can be online for surfing but not online to get the current time.

mcavic




msg:3733507
 2:39 pm on Aug 28, 2008 (gmt 0)

In Windows 2000 and XP, a restricted user shouldn't be able to change the clock (I just tried, and when I double-clicked the clock, it said I don't have access).

Also, a restricted user shouldn't be able to kill a process that's running as admin.

Makaveli2007




msg:3733799
 7:36 pm on Aug 28, 2008 (gmt 0)

Unfortunately in windows XP home I can change the clock from a restricted account...;(. My (more tech-savy than me) friends were surprised, too and said in windows XP professional it didn't work.

As for gpedit, the two (more tech-savy than me) friends asked me to do this right in the beginning, but it couldn't be found (b/c win xp home?).

Anyway, what I'll do now is either get a portable power outlet, put it in a safe box with a plug-in timer (etc.) or find a back up power resource kind of thing..sort of like batteries for the computer. Guess notebook + taking away the cabel to recharge the batteries would work, but for a stationary PC those back up power sources dont seem to last long enough.

Anyway, thanks for your help guys..despite my posting about windows when this forum is really about Linux/Unix.

Demaestro




msg:3733817
 7:53 pm on Aug 28, 2008 (gmt 0)

Log in with the Administrator account. Go to account management and turn on the "Guest" account.

I am 99% sure the "Guest" account can't alter anything including the time.

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