Is there a more granular cron-like scheduler? Instead of just by the minute, but at a certain second?
How to run scripts every 5 seconds?
Requires installation of untrusted packages? I tried installing VLC Player yesterday, and I got the Requires installation of untrusted packages error.  I searched for hours for a solution to this problem, and finally came upon a suggestion that said to change servers for downloading updates from.  I did this, and it gave me a 404 error when I clicked on "Check" in the Update Manager.  I tried switching my server back to the main one (and after that, several other ones), but I am now still getting a 404 error:   And the other error I get when downloading or updating:   Edit: Output of cat /etc/apt/sources.list:  deb-src http://us.archive.ubuntu.com/ubuntu/ precise main restricted #Added by software-properties  # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://us.archive.ubuntu.com/ubuntu/ precise main restricted multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise multiverse universe #Added by software-properties  ## Major bug fix updates produced after the final release of the ## distribution. deb http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates restricted main multiverse universe #Added by software-properties  ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb http://us.archive.ubuntu.com/ubuntu/ precise universe deb http://us.archive.ubuntu.com/ubuntu/ precise-updates universe  ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu  ## team, and may not be under a free licence. Please satisfy yourself as to  ## your rights to use the software. Also, please note that software in  ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team.  ## N.B. software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. deb http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse #Added by software-properties  deb http://us.archive.ubuntu.com/ubuntu/ precise-security main restricted multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise-security restricted main multiverse universe #Added by software-properties deb http://us.archive.ubuntu.com/ubuntu/ precise-security universe  ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. deb http://archive.canonical.com/ubuntu precise partner deb-src http://archive.canonical.com/ubuntu precise partner  ## This software is not part of Ubuntu, but is offered by third-party ## developers who want to ship their latest software. Is there a way to detect if a browser window is not currently active? Kernel of injective group homomorphism If $\phi$ is a homomorphism from the group $G$ with identity $e$ to the group $G'$ with identity $e'$, then $\phi$ is injective if and only if $\ker\phi=$?  I think the $Ker\phi = \{x\in G:\phi(x)=1\}$  because you are looking at an identity then it is all reals $0$ does not work a because if $x=0, e'x=0$  but then i realize it is injective how does that affect the kernel? Recursively delete empty directories in Windows I have a directory on my Windows 7 machine that has hundreds if not thousands of sub-directories.  Some of them have files, some do not.  I want to delete all the empty directories.  Looking at the del and rmdir DOS command, it does not look like you can recursively do this without deleting all the files.  Is there a way to do this from the command line? I tried to open the door. I tried opening the door   We can use both infinitive and gerund with verb "try" as used in above sentences. Does it change the meaning of the  sentence if use gerund or infinitive?.(here i don't know if the meaning of sentences is changed.)     The same confusion arise in these two sentences.  1.I stopped seeing him. 2. I stopped to see him.(But in case of these two sentence i know the meaning is changed but don't know exactly what the change is). How to combine bold and "code sample" in Markdown? Can I read the hash portion of the URL on my server-side application (PHP, Ruby, Python, etc.)? How can I fix Print Composer errors due to huge file size? Test to see when table is candidate for compression (row or page) Does anyone know a tool like this page  where one can determine if a table is a good candidate for row or page compression. Also I am trying to understand the benefits of compression. I have been reading about it, but still have these questions.  Will compression make more 8KB fit in the buffer cache? When does data become uncompressed i.e. in a select? will backups become faster? Is the reason that compression ads cpu overhead because e.g. inserts need to be compressed before the insert? Is there any good reason to compress tables without investigating how the tables is being used (i.e. static vs. volatile).  A colleague has started to compress many tables (page). I don't know the analysis behind this decision. I know we sometimes have resource semaphore waits during some peak hours. I actually don't think he knows what he is doing. I can see that our sos scheduler yield waits have gone slightly up. I think the compression is causing more harm and it seems that maintenance tasks overshoot more now (e.g. backups, checkdb...). Search [tag1] OR [tag2] Is there a way to search questions that are tagged with either tag1 or tag2?  Actually, I would like the general filter,      ([tag1] AND [tag2], ...) OR ([tag3]   AND [tag4], ...) OR ...   And even     [tag1] AND ([tag2] OR [tag3])   I need that because I'm looking for interesting questions and I have to search for each tag separately. Most incarnations of The Hulk I've seen or read about state that he is as strong as he needs, basically meaning that there is no limit to how strong he can get.  Is there any canon regarding this? Have we seen the upper limit of the Hulk's strength? The title kind of says it all. Is it possible to replace C# with C++ on a game using Unity? Show that the set of all finite subsets of $\mathbb{N}$ is countable. How to delete a Test Class WITHOUT using eclipse I cannot install Eclipse, even if I wanted to.  It is not approved software for my org.  How can test classes be deleted from production, using deployments? There no 'active' checkbox when I am editing the classes in sandbox mode, so I can't just deactivate the test class, and i cant deploy a deleted class to prod...  how the heck is this done?  I dont want to use ANT or special software.  SF must have a native way to achieve this.  And if not...  then I am very disappointed in humanity. Jquery load() and PHP variables I'm getting the following error message:     System.QueryException: Didn't understand relationship 'AccountContactRelation' in FROM part of query call. If you are attempting to use a custom relationship, be sure to append the '__r' after the custom relationship name. Please reference your WSDL or the describe call for the appropriate names.   Select Email, Id, (Select ContactId, AccountId From AccountContactRelation) From Contact  In AccountContactRelation object there are two lookup fields for Account and for Contact.  Please advise how to avoid such error message? No notification (+15) for accepted answer Spam iCloud Calendar Invitations find() function in python2.7.5 The characteristic and minimal polynomial of a companion matrix of a monic polynomial $f \in \mathbb F\left[x\right]$ in $1$ variable $x$ over a field $\mathbb F$ plays an important role in understanding the structure of finite dimensional $\mathbb F[x]$-modules.  It is an important fact that the characteristic polynomial and the minimal polynomial of $C(f)$ are both equal to $f$. This can be seen quite easily by induction on the degree of $f$.  Does anyone know a different proof of this fact? I would love to see a graph theoretic proof or a non inductive algebraic proof, but I would be happy with anything that makes it seem like more than a coincidence!