add ll alias In Ubuntu server
How do I create a permanent Bash alias?
So far, I know the matrices $$S=\left( \begin{matrix} 0&amp;-1\\ 1&amp;0 \end{matrix} \right), \quad T=\left( \begin{matrix} 1&amp;1\\ 0&amp;1 \end{matrix} \right) $$ generate SL$(2,\mathbb{Z})$. $S^2=(ST)^3=-I$. I also know the matrices $$X=\left( \begin{matrix} 1&amp;1\\ 1&amp;2 \end{matrix} \right), \quad Y=\left( \begin{matrix} 2&amp;1\\ 1&amp;1 \end{matrix} \right) $$ with their inverses $X^{-1},Y^{-1}$ generate SL$(2,\mathbb{Z})'$, the commutator subgroup. I'm interested in what the quotient $SL(2,\mathbb{Z})/SL(2,\mathbb{Z})'$ is. In general, how would I go about computing the quotient of two matrix groups? I'm trying to use GAP but I'm having a lot of trouble! Anthem-esque short story about a dude who is very smart and strong so he wears devices to slow him and weaken him I remember reading a short story back in high school that was similar to Anthem by Ayn Rand about this guy who was very strong and smart. And because everyone in this world had to be equal he was forced to wear weights to slow him down, and he had to wear some device on his head that made it hard for him to see and hear, breaking his focus.  At the end of the story in breaks into a news station and tries like broadcasting a message. And he runs away with one of the ballerinas who has blocks on her feet so it makes it hard for her to dance. Zip folder without including path to folder and require only one argument I'm trying to make a zip function that'll do all the steps I typically do when zipping a file or folder. Say my current directory is ~, and I want to zip a folder named Folder1, whose file path is ~/Folder2/Folder1.  Issuing  cd ~/Folder2 &amp;&amp; zip -r Folder1 Folder1 &amp;&amp; cd -   does exactly what I want. Namely, it zips so that the output Folder1.zip does not contain folders that lead up to the folder I'm zipping (namely, /home/user/Folder2), it zips recursively, and it takes in the first argument of zip with the exact name as the file or folder I'm zipping (Folder1.zip).  So I want to make a function in my .zshrc something akin to  coolerzip() { cd /path/to/file &amp;&amp; zip -r file file &amp;&amp; cd - }   where it need only take in one argument, which in this case, it will be ~/Folder2/Folder1. Then Folder1 will be the name for both files in coolerzip, and I will cd right into ~/Folder2 so Folder1 lies in my current directory before zipping. Is there any way I can achieve this so that coolerzip only requires one argument rather than three? How to add CC to a webform email? I'm using Drupal 7.  Is it possible to add a CC to a webform email?  I was using   function theme_webform_mail_headers($variables) {   $headers = array(     'X-Mailer' =&gt; 'Drupal Webform (PHP/' . phpversion() . ')',   );   return $headers; }   changing it with      function MYTHEME_webform_mail_headers($variables) {       $headers = array( 'CC' =&gt; 'ccmeail@domain.com', 'X-Mailer' =&gt; 'Drupal Webform (PHP/'. phpversion() .')',  );       return $headers;     }   It does not work, I've cleared all the chaches and it does not add the CC. How could I add the CC?  Thanks in advance. Was Luke aware the Emperor was a Sith Lord? Similar to , I'm asking the more specific question, was Luke aware that the Emperor was a Sith Lord? I don't recall it being mentioned in any of the films.  If yes, at what point does he learn this? If not why did Yoda or Obi-Wan not warn him?  Perhaps he could have avoided being defenseless and struck by Force Lightning if he'd been made aware? How do I remember which units counter which in StarCraft 2? Can I skip over releases when upgrading? To tell about a guess about a case in the past, why use "would+have+past participle" instead of "must+have+past participle? I have seen this sentence in an article on bbc, which is about how people lived thousands of years ago. &quot;When this Neolithic home was built, it would have had a cosy roof of turf..&quot; When I read it, I got confused. Because the fact seems as a simple past situation or guessing/assumption about something in the past. it simply gives information about a past event, eg &quot;when I was a child, I had a blue toy car. I have been making a lot of research on whether or not this structure &quot;would+have+past participle&quot; could be used instead of the simple past or &quot;must+have+past participle&quot;, but I could not find any satisfying explanation. Almost all grammer contents cover this structure is used when we imagine the opposite of what actually happened in the past eg. &quot;referring to a missed opportunity&quot; (eg. &quot;if you had come to the party, you would have seen Tom.&quot;), But, in this case of this sentence, &quot;type 3 conditional&quot; is irrelevant. It is not an if sentence,  It simply gives information about how this house was like or was probably like when it was built long ago. Just like it would be If and old lady would want to tell about &quot;how she was like when she was a child years ago. she would simply say &quot;when I was a child, I had long curly hair.**. So &quot;when I was a child, I would have had long curly hair.&quot; would be wrong. So, my question is: 1-Does this structure &quot;would+have+past participle&quot; completely replace simple past sentences? or can be it be used instead of simple past? 2- If this structure was simply used because the author was not %100 sure about the fact as it was a long long time ago -so he wanted to make a guess or assumption, why did he not simply use &quot;must+have+past participle&quot; or &quot;it was likely that blah blah&quot; which must be used for guessing or assumptions about past happenings. Would it not have made more sense if it was like: &quot;When this Neolithic home was built, it must have had a cosy roof of turf. How to ignore the first line of data when processing CSV data? Word to describe the way cattle and buffalo consume fodder? I have recently installed lubuntu 11.10 on my old laptop (acer aspire 5315 celeron) and observed that fan is not working properly on lubuntu side.I find it strange that it is working perfectly under window vista.   How could I solve this problem? I am trying to use netcat to send a simple message over TCP, e.g. I want to send the digit 1.  So I understood that I write the following in the terminal, after installing netcat  netcat [ip-address] [port]  But how do I specify the message to be sent? i.e. where to I write "1" ? Override a method at instance level java.lang.IllegalArgumentException: Invalid  in servlet mapping &lt;servlet&gt;     &lt;servlet-name&gt;myservlet&lt;/servlet-name&gt;     &lt;servlet-class&gt;workflow.WDispatcher&lt;/servlet-class&gt;     &lt;load-on-startup&gt;2&lt;/load-on-startup&gt; &lt;/servlet&gt;  &lt;servlet-mapping&gt;     &lt;servlet-name&gt;myservlet&lt;/servlet-name&gt;     &lt;url-pattern&gt;*NEXTEVENT*&lt;/url-pattern&gt; &lt;/servlet-mapping&gt;   Above is the snippet from Tomcat's web.xml. The URL pattern *NEXTEVENT* on start up throws     java.lang.IllegalArgumentException: Invalid &lt;url-pattern> in servlet mapping   It will be greatly appreciated if someone can hint at the error. ­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­ Sarrus Rule with LaTeX I have got hundreds images of products with clear white backgrounds. I would like to change the white background color to become transparent.   Is there a means of batch processing this particular process with Photoshop or any other applications? How can I convert from a SID to an account name in C# I have a C# application that scans a directory and gathers some information.  I would like to display the account name for each file.  I can do this on the local system by getting the SID for the FileInfo object, and then doing:  string GetNameFromSID( SecurityIdentifier sid ) {     NTAccount ntAccount = (NTAccount)sid.Translate( typeof( NTAccount ) );     return ntAccount.ToString(); }   However, this does not work for files on a network, presumably because the Translate() function only works with local user accounts.  I thought maybe I could do an LDAP lookup on the SID, so I tried the following:  string GetNameFromSID( SecurityIdentifier sid ) {     string str = "LDAP://&lt;SID=" + sid.Value + "&gt;";     DirectoryEntry dirEntry = new DirectoryEntry( str );     return dirEntry.Name; }   This seems like it will work, in that the access to "dirEntry.Name" hangs for a few seconds, as if it is going off and querying the network, but then it throws a System.Runtime.InteropServices.COMException  Does anyone know how I can get the account name of an arbitrary file or SID?  I don't know much about networking or LDAP or anything.  There's a class called DirectorySearcher that maybe I'm supposed to use, but it wants a domain name, and I don't know how to get that either - all I have is the path to the directory I'm scanning.  Thanks in advance. Default gender, "Male" or "Female" Should our default gender when selecting male/female on the dropdown list be based on the local  (if a country have more female than male then female is the default value)? Can I successfully bake previously-frozen bread dough? We want to show that if $a,b\in G$ where $G$ is a finite Abelian group, we have  $\operatorname{LCM}(|a|,|b|) = |ab|$ given that $ab \neq e$.   How I approached this question was by saying let $\operatorname{LCM}(|a|,|b|) = L$. Then if we show that $L$ divides $|ab|$ and $|ab|$ divides $L$ then $|ab| = L$. Showing that $|ab|$ divides $L$ was fine. But then I am having trouble with the second part that is showing $L$ divides $|ab|$. For this, so far I have:  Consider $(ab)^{|ab|} = e = a^{|ab|}b^{|ab|} $  since we know $a \neq b^{-1}$ by assumption then we can conclude that $|a|$ divides $|ab|$ and $|b|$ divides $|ab|$. We know that $L = \frac{|a||b|}{\operatorname{gcd}(|a|,|b|)}$ from here can we conclude that $L$ divides $|ab|$?