The way i understand the use of tar + gzip is that tar is normally used to consolidate a grouping of files into a single file, then gzip is used to compress that file.  I recently learned that tar can also compress.   Because I do not fully understand how compression works @ it's core, I have (possibly ridiculous) concerns that sending a pre-compressed .tar to gzip might prevent gzip from compressing as well as it's potential would allow and things of that nature.   My question is essentially:  What combination of args/compression methods should i use to create the absolute smallest tar.gz, and what does the command line statement look like for that?
I gzip directories very often at work. What I normally do is  tar -zcvf file.tar.gz /path/to/directory   Is there a way to specify the compression level here? I want to use the best compression possible even if it takes more time to compress.
How do I force TeX to completely use the 1st column before writing to the second column?  Right now I dont have enough content to fill one whole page. So the left and right columns are equally filled, leaving 25% symmetrical empty page at bottom. How do I fill the left column first, and then the right?  \documentclass{article}  \usepackage{multicol} \usepackage[scale=0.9]{geometry} \usepackage{amssymb} \renewcommand{\labelitemi}{\tiny$\blacksquare$} \begin{document} \begin{multicols}{2}      %lots of text goes here  \end{multicols} \end{document} I just reached the 3k rep limit required for close votes and have started exploring the vote-to-close UI that's opened up to me, and I have a request.  The review queue has a Do Not Close button, but when I click the close link under a question that has close votes (i.e. it shows close (1)), there isn't an option for me to vote against closing the question. I came across a question that had a vote to close it as not a question, but it had just been updated with code and more details and was no longer a candidate for closing. However, I couldn't cast a vote to not close it from the question itself. When I clicked on close, it brought up the usual voting UI, and "Do Not Close" was not an option.  TL;DR, do this:   Open a question in the close votes review queue Note the Do Not Close button Click the question title to go to it Click the close (n) link under the question (assuming it hasn't already been closed) Notice the lack of an equivalent "Do Not Close" option   Could a "Do Not Close" option be added to the close button popup for questions that already have close votes, that way the review interface isn't the only place a "Do Not Close" vote can be cast?  Edit: Okay, so 5 3 "Do Not Close" votes kicks it out of the review queue, it doesn't have "no effect" as suggested in the comments. (See , in which the  was just updated a few minutes ago to say 3 DNC votes.) I still don't see why the same DNC option can't be available from the question.  Basically, I guess I would like some rationale behind this bullet point from :     Only accessible from the review queue (so rather difficult to target a specific question). Yes, this is very much by-design. Is Unit Testing worth the effort? I am working to integrate unit testing into the development process on the team I work on and there are some sceptics. What are some good ways to convince the sceptical developers on the team of the value of Unit Testing? In my specific case we would be adding Unit Tests as we add functionality or fixed bugs. Unfortunately our code base does not lend itself to easy testing. How to deal with a Pell's equation type problem with two primes Humans don't digest fibre, and nor do any animals, but some creatures have micro-organisms (bacteria, I'm guessing) in their gut which digest fibre for them.  My question is, could humans take some sort of pill and establish our own fibre-digesting colonies in our intestines?  Has this been tried?  Supposing it could be done, would you suppose it would have any negative effects on our health?  (i.e.. would those whose gut digested fibre for them be stuck on a low-fibre diet?).    Purpose of question: just wondering.  It would be cool to be able to eat bark. Why are cryptography algorithms not exported to certain countries? There have been strict laws about the export of crypto software to certain countries. I can understand the intent, but never gauged the fact that there is nothing stopping these countries from developing their own crypto software. So why limit the export?   And in light of the recent NSA revelations, of backdoors being engineered into crypto algos, wouldn't the export of such compromised algorithms have helped to unravel secrets? How do suggested edits work? When clicking &quot;edit&quot; I see:  Your edit will be placed in a queue until it is peer reviewed. We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.  Like:     Likewise, when I am not logged in, clicking &quot;improve this question&quot; or &quot;improve this answer&quot; shows:  You are not . Your edit will be placed in a queue until it is .  And when I click 'Save', I get:  Thanks for submitting an edit. It is only visible to you until it's been approved by trusted community members  Like:     Who can suggest an edit? Where do suggested edits go? Who can vote on a suggested edit? How do suggested edits get reviewed? Can I earn reputation? What about abuse or bad edits? Sometimes the Community user approves or rejects my edit. Why is that? When can I not suggest an edit? Is there a minimum change requirement for a suggested edit? How do I check my suggested edit history? I disagree with the reasons why my suggested edit was rejected. What can I do? How do I know whether there are edits waiting for review? Someone suggested an edit to my own post, and the reviewers took the wrong action. What can I do? Are tag wikis included in this scheme? What do the &quot;Improve Edit&quot; and &quot;Reject and Edit&quot; buttons do? Why are apparently valid links to rejected edits resulting in 404 errors?   For more information about editing, see &quot;&quot; in the . How to convert an instance of std::string to lower case I am looking for      an example of a ring where unique factorization does not hold. However the ring is supposed to have the property that every irreducible is already a prime.    So unique factorization should fail because one cannot decompose every element into a finite product of irreducibles. In particular the ring must not be Noetherian. What is an example of such a ring? Why does inertia happen? In  R P Feynman relates a story where his father told him that, even though we know the word "inertia" and what it means, nobody knows why inertia happens. Is that still true? Can $3p^4-3p^2+1$ be square number? Power series of a function I am wondering if there are any functions $f(x)$ such that it cannot be expressed as a power series of $x$? This might turn out to be a silly question, but I can't think of one at the moment.   Thanks! What is the difference between varchar and nvarchar? I'm sure there is a really simple explanation to this but haven't found any pointers on this forum or elsewhere. I seem to have lost the 'processing' menu from QGIS and can't figure out how/why!? Any ideas what I might have done to make this happen?  I'm running QGIS 2.8 built against GDAL 1.10 on Ubuntu 14.04. We are planning a trip with a bike rack attached to our trailer hitch. What is the best way to lock the bikes while the vehicle is unattended? I see some racks have locks on the knobs but they don't seem very strong.   What do you suggest? Google Sheets Customize View Using Create Custom Menu and Hiding/Showing Specifc Columns Trying to determine a way that I can use a custom menu (.createMenu) with views that will allow me to show / hide specific columns.  I need the capability to pick specific multiple columns and not ranges.  In the example below how can you pick a custom view from the menu (say "Customer Info") that will only show columns A, B, C, and H?  Maybe another view could show "Financial". Reference for the subgroup structure of $\rm{PSL}_2(q)$ Proof that every polynomial of odd degree has one real root I want to prove that every real polynomial of odd degree has at least one real root, using  the intermediate value theorem.  Let $P(x) = x^{2n+1} + a_n x^{2n} + . . . + a_0$ for each $a_i \in \mathbb{R}$ and $n \in \mathbb{N}$.  By the fundamental theorem of algebra I know that $P(x)$ has exactly $2n+1$ complex roots, so  $P(x) = (x+r_1)(x+r_2) . . . (x+r_{2n+1})$ for each $r_i \in \mathbb{C}$  I do not know how to complete this but I do know that, at some point, I probably have to show that each root with imaginary part non zero has to come in conjugate pairs, and since $2n+1$ is odd there is at least $1$ root that is imaginary part $0$ and thus real. $\mathbb{Q}(\sqrt{p},\sqrt[3]{q})= \mathbb{Q}(\sqrt{p}\cdot \sqrt[3]{q})$ ?? Using VHDL code to design a JK Flip Flop I'm using quartus II to design a JK Flip Flop. However, my results show unknown output. Why is it?  Intended design circuit:    VHDL code:  library IEEE;  use IEEE.STD_LOGIC_1164.ALL;  entity JKFlipFlopGate is     port(         J,K,Clk : in std_logic;             --JK Flip-Flop gate input 1 &amp; 2         Q,Qbar : out std_logic              --JK Flip-Flop gate output     ); end JKFlipFlopGate;  architecture result of JKFlipFlopGate is         signal out1,out2,out3,out4 : std_logic;  begin     out1    &lt;= NOT(J AND Clk AND out4);                      out2    &lt;= NOT(K AND Clk AND out3);      out3    &lt;= out1 NAND out4;     out4    &lt;= out2 NAND out3;      Q       &lt;= out3;     Qbar    &lt;= out4;     end result;