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Joined 11 months ago
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Cake day: December 26th, 2023

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  • I think what happened here is that something went wrong and messed up the permissions of some of the users files. MS help suggested that he login as an administrator and reatore the intended permissions.

    I don’t work with Windows boxes, but see a similar situation come up often enough on Linux boxes. Typically, the cause is that the user elevated to root (e.g. the administrator account) and did something that probably should have been done from their normal account. Now, root owns some user files and things are a big mess until you go back to root and restore the permissions.

    It use to be that this type of thing was not an issue on single user machines, because the one user had full privileges. The industry has since settled on a model of a single user nachine where the user typically has limited privileges, but can elevate when needed. This protects against a lot of ways a user can accidentally destroy their system.

    Having said that, my understanding of Windows is that in a typical single user setup, you can elevate a single program to admin privileges by right clicking and selecting “run as administrator”, so the advice to login as an administrator may not have been nessasary.




  • Java did have a Security Manager that can be used to prevent this sort of thing. The original thinking was that the Java runtime would essentially be an OS, and you could have different applets running within the runtime. This required a permission system where you could confine the permissions of parts of a Java program without confining the entire thing; which led to the Java security manager.

    Having said that, the Java Security Manager, while an interesting idea, has never been good. The only place it has ever seen significant use was in webapps, where it earned Java the reputation for being insecure. Nowadays, Java webapps are ancient history due to the success of Javascript.

    The security manager was depreciated in Java 17, and I believe removed entirely in Java 21.



  • There are still a lot of rather arbitrary decisions to make.

    Is 4/pi inside or outside of the summation?

    Is it (-1)^n+1 or (-1)^n with an additional negative sign in any of the other natural locations for it.

    Is the e term outside of the fraction with a negative exponent, or part of the denominator.

    Do you start with n=0 or n=1 (and adjust the terms inside the summation accordingly)

    Did they expand (2n+1)^2?