When trying to extend a script, for some reason, if a sed expression is inside a variable it won't run. Minimal example: echo lorem &gt;&gt; /tmp/testsed CMD=&quot;sed --debug -i.bak -e 's/lorem/ipsum/' /tmp/testsed&quot; $CMD  results in: sed: -e expression #1, char 1: unknown command: `''  I've looked at a few (, ,  and  ) similar posts, but none solved the issue. For now I'm using eval (like 4 initially suggests), but it's not an ideal solution; also creating a function is not an option. I feel like it's related to having to escape some characters on the expression, but from my tests I could not find which. This sed expression is set as a action that another script executes after some specific action.
$ ls -l /tmp/test/my\ dir/ total 0   I was wondering why the following ways to run the above command fail or succeed?  $ abc='ls -l "/tmp/test/my dir"'  $ $abc ls: cannot access '"/tmp/test/my': No such file or directory ls: cannot access 'dir"': No such file or directory  $ "$abc" bash: ls -l "/tmp/test/my dir": No such file or directory  $ bash -c $abc 'my dir'  $ bash -c "$abc" total 0  $ eval $abc total 0  $ eval "$abc" total 0
I can buy Dell Latitude E7270 through my employer. It will come with Windows, but I would like to install Ubuntu (most likely 14.04). This model does not appear on the list of certified hardware, however. Does anyone know whether I should anticipate any problems with his laptop? Thanks! SGS2 screen gets more and more dark blue, possibly after overheated charging Bottom to top explanation of the Mahalanobis distance? How to add desktop shortcut for URL, ignoring web app manifest? Goal:  Have a desktop shortcut that opens  , ignoring the contained web app manifest that otherwise "overrides" the saved shortcut to  and with "display": "standalone".  I had this working previously on an older Android phone before a replacement / upgrade.  Prior to the upgrade, I was able to long-press and open individual articles in new tabs - as well as copy link shortcuts to specific articles, as well as all of the other features and functionality that Chrome has to offer.  Here is just a partial selection of references of other users complaining about the same:       Using  provides a temporary successful work-around.  However, I can't find a successful way to add a link for this to my home screen.  The "Add to Home screen" option within Chrome instead saves a link to  - and in such a way that it opens as a web application instead of a web page within Chrome:       On a desktop operating system, this would be a non-issue.  (Create shortcut, enter desired URL, done.)  Attempt 1: Provide my own Manifest  So I created my own manifest - editing  to change the start_url attribute to https://news.google.com/news/i#0, and the display attribute from standalone to browser.  I then created my own HTML page that simply contained the below - then self-hosted both on a local web server:  &lt;html&gt;         &lt;head&gt;                 &lt;Title&gt;Google News&lt;/Title&gt;                 &lt;link rel="manifest" href="/news/manifest.json"/&gt;         &lt;/head&gt;         &lt;body&gt;                 Test         &lt;/body&gt; &lt;/html&gt;   However, this doesn't work:  Despite the shortcut being saved with the desired name and icon, it links back to my self-hosted HTML page, and not the indicated start_url.  Unfortunately, it appears that cross-domain URLs are not allowed per the manifest intent - as per  and  .  Attempt 1b: MITM website  Within the confines of my own local network, I figured I could try to  (MITM) the website to temporarily provide a desired manfiest to use for addition to the home screen.  Unfortunately, the website uses  here, which appropriately blocks the attempt.  Regardless - this is way too much work for what should be a simple effort.  Attempt 2: Widget Bookmark  Unfortunately, it looks like the 1x1 bookmark widget was removed in Chrome 48, as per  .  The suggested work-around is to use the "Add to Home screen" feature within Chrome.  Goto 10 / see beginning.  Attempt 3: Use the default-provided "Internet" browser  Unfortunately, using "Add shortcut on Home screen" in the default-provided "Internet" browser produces the same result as Chrome.  Consideration 4: Use a custom app / widget  Could probably write and install a custom application or widget that could be added to the home screen to meet the goal.  Or don't re-invent the wheel, and use an existing one.  Some possibilities:   "More Shortcuts":  "Shortcut Customizer":    Conclusion  How can someone create a desktop shortcut to an arbitrary URL, ignoring a provided web app manifest? In my custom Drupal 8 plug-in I perform such query:  $select = db_select('my_table', 'e'); $select-&gt;addField('e', 'field1');  $select-&gt;condition('field3', 'NULL', '!='); $select-&gt;condition('field4', array(11, 12, 31, 32, 33), 'IN');  $select-&gt;groupBy("e.field1"); $select-&gt;orderBy("e.field1"); $select-&gt;orderBy("e.field5"); $entries = $select-&gt;execute()-&gt;fetchAll(\PDO::FETCH_ASSOC);    And it works fine. It returns me all records grouped by field1 that meets the condition, orderered. But it returns only field1 column.  I wanted to get more columns, so I have added another $select-&gt;addField('e', 'field2'); just after first one:  $select = db_select('my_table', 'e'); $select-&gt;addField('e', 'field1'); $select-&gt;addField('e', 'field2');  $select-&gt;condition('field3', 'NULL', '!='); $select-&gt;condition('field4', array(11, 12, 31, 32, 33), 'IN');  $select-&gt;groupBy("e.field1"); $select-&gt;orderBy("e.field1"); $select-&gt;orderBy("e.field5"); $entries = $select-&gt;execute()-&gt;fetchAll(\PDO::FETCH_ASSOC);    This time I get error:     Drupal\Core\Database\DatabaseExceptionWrapper: SQLSTATE[42000]: Syntax error or access violation: 1055 Użyto 'my_database.e.field2' bez umieszczenia w group by:   Which means "my_database.e.field2 has been used without putting in into group by". But I don't want to group by every column I select.  Unfortunatelly Drupal 8 added ONLY_FULL_GROUP_BY :( Then, how can I use groupBy and select more then one column at the same time? In biblatex, treat periods in journal as abbreviation dots I would like to consistently have a comma between the journal and volume number for article references using biblatex with biber as the backend. Unfortunately, the punctuation between the journal and volume is not consistent. Journals whose last word is abbreviated have no comma between the journal and the volume, and the word "Vol." is capitalized. Journals whose last word is not abbreviated have a comma and the word "vol." is not capitalized. I can fix the capitalization by un-commenting the commented lines in the below MWE, but the comma problem is quite perplexing. Apologies if this fix is in an answer somewhere, but I cannot find it (or at least, I don't know what to search for!).  Current output: [1] First Author. “Blah Blah 2”. In: Am. J. Phys. Vol. 72, no. 3 (Mar. 2004), pp. 367–375. [2] Second Author. “Blah blah”. In: Energy Fuel, vol. 27, no. 12 (Dec. 2013), pp. 7778–7789.  Expected output: [1] First Author. “Blah Blah 2”. In: Am. J. Phys., vol. 72, no. 3 (Mar. 2004), pp. 367–375. [2] Second Author. “Blah blah”. In: Energy Fuel, vol. 27, no. 12 (Dec. 2013), pp. 7778–7789.  MWE:  \documentclass{article} \usepackage{filecontents} \usepackage[     backend=biber,     citestyle=numeric-comp, ]{biblatex} \addbibresource{\jobname} % \DefineBibliographyStrings{english}{%     % volume = {\lowercase{v}ol\adddot}, % avoid capitalization after dots. % } \DeclareFieldFormat[article]{volume}{\bibstring{volume}\addspace #1} \DeclareFieldFormat[article]{number}{\bibstring{number}\addspace #1} \renewbibmacro*{volume+number+eid}{%   \printfield{volume}%   \setunit{\addcomma\space}%&lt;---- was \setunit*{\adddot}%   \printfield{number}%   \setunit{\addcomma\space}%   \printfield{eid}} \renewbibmacro*{journal+issuetitle}{%   \usebibmacro{journal}%   \setunit*{\addcomma\addspace}%&lt;---- was \setunit*{\addspace}%   \iffieldundef{series}     {}     {\newunit      \printfield{series}%      \setunit{\addspace}}%   \usebibmacro{volume+number+eid}%   \setunit{\addspace}%   \usebibmacro{issue+date}%   \setunit{\addcolon\space}%   \usebibmacro{issue}%   \newunit}  \begin{filecontents*}{\jobname.bib} @article{York2004, author = {Author, First}, journal = {Am. J. Phys.}, month = mar, number = {3}, pages = {367--375}, title = {{Blah Blah 2}}, volume = {72}, year = {2004} } @article{Baumgardner2013a, author = {Author, Second}, journal = {Energy Fuel}, month = dec, number = {12}, pages = {7778--7789}, title = {{Blah blah}}, volume = {27}, year = {2013} } \end{filecontents*}  \begin{document} \nocite{*} \printbibliography \end{document} How can I secure an Ethernet-over-power network? I just bought myself an Ethernet-over-power adapter, and plugged it in. It seems to be working great, but now I'm concerned that my neighbours may be able to access my network.  I live in a rowhome complex; is it possible they can access my network? If so, how can I secure it? How do you detect a network disconnection when downloading a file in java? How do I run 32-bit programs on a 64-bit Debian/Ubuntu? I have a 64-bit (amd64 a.k.a. x86_64) Debian or Ubuntu installation. I need to run 32-bit (i386/i686) programs occasionally, or to compile programs for a 32-bit system. How can I do this with a minimum of fuss?  Bonus: what if I want to run or test with an older or newer release of the distribution? I'm unable to update nodejs, and I can't see why.  If I were to make a guess, I'd say that I have two repositories listed in apt-get, that both contain a nodejs package.  Here's what I've done:  Remove old version:  sudo apt-get remove --purge nodejs npm   Then, going by , I've run:  curl -sL https://deb.nodesource.com/setup_5.x | sudo -E bash -   And then:  sudo apt-get install -y nodejs   I then run:  nodejs -v   Which returns:  v0.10.25   Can anyone explain what's going wrong? And how I can remedy this situation?  Many thanks. How do I prevent the blank screensaver when using keyboard shortcut to lock the computer? $\mathbb{R}P^4$ and $\mathbb{R}P^6$ do not admit fields of tangent $2$-planes Installing Kali on a USB drive - NOT Live USB or Persistence partition Greeting's, to clarify; my question is not creating a Live USB drive or a persistence partition but creating a USB with GRUB bootloader (or other) and Kali which can be used on any machine. This is similar to running other linux OS directly from USB. I am currently running Ubuntu from a pen drive. I installed the OS (Ubuntu) and the bootloader on the pen drive and I can boot off it anywhere. Here is a video explaining the same (video is not by me: )  Since, Kali's installer doesn't give option to select which drive to write the booloader to and directly writes on the HDD (sda1). This means even if I partition and install Kali on a pen drive since the bootloader will be installed on the machines fixed primary drive, the USB drive will fail to boot on a different device.  I have two questions:   Anyone has any idea how to write bootloader to a USB drive and what parameters should be given so that it boots with Kali installed on it. I am using graphic install mode for installing Kali on the USB drive, however there is no option for the install to be encrypted (Full disk encryption or at least /home folder to be encrypted). Does anyone know how can I install Kali with full disk / home folder encryption? Or enable is post install?   Thank You! Why doesn't this C++0x code call the move constructor? Does an unbalanced sample matter when doing logistic regression? Okay, so I think I have a decent enough sample, taking into account the 20:1 rule of thumb: a fairly large sample (N=374) for a total of 7 candidate predictor variables.   My problem is the following: whatever set of predictor variables I use, the classifications never get better than a specificity of 100% and a sensitivity of 0%. However unsatisfactory, this could actually be the best possible result, given the set of candidate predictor variables (from which I can't deviate).   But, I couldn't help but think I could do better, so I noticed that the categories of the dependent variable were quite unevenly balanced, almost 4:1. Could a more balanced subsample improve classifications? Windows 7 + Deep Freeze - I'm stuck in an endless reboot loop I have the following setup:   Windows 7 Ultimate Deep Freeze   I "thawed" my machine last night and performed a Windows Update. The update is having issues (it gets stuck at 32%, fails, and restarts my machine). When it reboots it attempts it again, and again, and again, etc. (Endless loop).  I looked online and found some solutions, but none of them seem to be working:   When I run Safe Mode, Safe Mode w/ Network, or Safe Mode w/ Command Prompt it attempts to revert the Windows Update changes. However, the problem is with Deep Freeze on (and now in "Frozen" mode) the reverted changes don't stay, and I'm back into the loop of death. Oh, and side note: "Safe Mode w/ Command Prompt" does not actually take me to a command prompt window? Perhaps because it is attempting to complete the Windows Update changes first? I have tried to select the option to NOT restart when an windows error occurs, but it still does. I tried the remainder of all the other options in the F8 screen.     The only other option left is to find my Windows 7 Media Disc (I can't find it right now) and use it to repair windows (because for some reason the repair option does not show up in the F8 screen).  Is there a way to disable Deep Freeze from loading? When I selected "Safe Mode w/ Command Prompt" I noticed that it loads the DpFrz.sys file. I know that when I'm in the Windows Boot Manager if I press F10 instead of F8 (while highlighting Windows 7) it takes me to an "Edit Boot Options" screen:     Edit Windows boot options for: Windows 7      Path: \Windows\system32\winload.exe      Partition: 2 Hard Disk: 8e90e329      [ /NOEXECUTE=OPTIN (I CAN EDIT THIS LINE)   ]     Update: I found my Windows 7 Media Disk and it did not help out. The laptop had the "System Restore" as a partition on the HDD. I later received (in the mail) a Windows 7 Upgrade Disc from Sony to upgrade my system from Windows Vista to Windows 7 Ultimate. I placed the disc into the DVD drive and it does not come up as a "bootable" disc. I'm going to try to find an alternative disc to see if I can get into Command Prompt.    Update 2: I got a Windows Repair disc and got into a command prompt window. I got into the registry and disabled Deep Freeze. Also:   I renamed the Pending.xml file to Pending.old I cleared out the Windows Temp directory   I still am stuck in the loop (though, it isn't an issue with DeepFreeze anymore because I can make changes to the hard drive and they persist). Not sure what to do at this point?    Update 3: I ran the repair option and it couldn't repair, but it did point me to something. It says the error was due to a driver that was failing. I have a feeling it is my UPEK Fingerprint scanner. Prove $\gcd(a+b,a^2+b^2)$ is $1$ or $2$ if $\gcd(a,b) = 1$ Assuming that $\gcd(a,b) = 1$, prove that $\gcd(a+b,a^2+b^2) = 1$ or $2$.   I tried this problem and ended up with $$d\mid 2a^2,\quad d\mid 2b^2$$ where $d = \gcd(a+b,a^2+b^2)$, but then I am stuck; by these two conclusions how can I conclude $d=1$ or $2$?  And also is there any other way of proving this result? Find a recurrence relation for the number of ways to arrange $n$ dominoes to fill a $2$ by $n$ checkerboard. I am having trouble with this question, please take a look at it:     Find a recurrence relation for the number of ways to arrange $n$ dominoes to fill a $2$ by $n$ checkerboard.   I have just started reading the topic and it is one of the starting problem. Please help. You can give me some hints, a complete answer is also appreciated.  Thanks Comparing two strings in Bash I have the following if block in my bash script:  if [ ${PACKAGENAME} -eq kakadu-v6_4-00902C ]; then   echo "successfully entered if block!!" fi   The script execution is not entering my if block even though $PACKAGENAME is equal to kakadu-v6_4-00902C. What am I doing wrong? Copy material to another object? I saw a video where the person copied a material from one object to another (Cycles).  How can I accomplish this?