I understand the difference between  and , but my question is why do they have both? It seems like an unnecessary complication. Why not just store the encrypted password in the passwd file? Is it somehow more secure separating them? I noticed passwd is accessible to anyone but shadow only to superusers.
What is the purpose of the /etc/shadow file in Linux Operating system?  Also, is it same for SUSE clients? There is one shadow cache file is maintained what is purpose of that?
A book suggests that we should not interchange "so" and "so that". "So" means "therefore", and "so that" means "in order that". However, it seems to me that in many cases they don't actually have a difference. For example:     Alice got up at 5:00 A.M., so that she could drive her son to school.   If I substitute "so that" with "so", this sentence presents the exact same causal relation to me:     Alice got up at 5:00 A.M., so she could drive her son to school.   I must have missed something here, since English is my second language. Could somebody explain the difference? How to get multiple selected values of select box in php? How can I remove the BOM from a UTF-8 file? I have a file in UTF-8 encoding with BOM and want to remove the BOM. Are there any linux command-line tools to remove the BOM from the file?  $ file test.xml test.xml:  XML 1.0 document, UTF-8 Unicode (with BOM) text, with very long lines using $$ in a post causes strange number series to appear Lightsabers are not made of light, nor have they anything to do with lasers (even if there are people who mistakenly refer to them as "laser swords").   Blaster bolts are also not lasers. They travel significantly slower than light, they travel even slower than ordinary bullets fired by gunpowder. (called slug throwers on the Star Wars universe)  Was there any use of lasers ever presented in the Star Wars universe, either as we use them today, or as weapons?  By laser I mean something which behaves like laser does, even if it's not called by that name in a movie or book. If something is called a laser (in the script or by fans) but clearly doesn't work like a laser (for example, it travels slowly, and in visible blocks) it doesn't count. Pages documents created on Yosemite cannot be opened by Pages on Yosemite after latest update (5.5.2) Seemingly every single document that I created in the previous version of Pages (I update regularly whenever I see that a new update is available) on this same MacBook Pro with Yosemite will now not open with Pages after the latest update (5.5.2). I am still on Yosemite and nothing has changed aside from updating Pages, Numbers &amp; Keynote.  All of my documents are stored on my internal hard drive. When I attempt to open them I get a message stating the following:     This document can't be opened because it's too old. To open it, save it with Pages '09 first.   As I mentioned above, however, these documents were created in whichever version was right before the current version on the same computer with the same operating system (Yosemite).  Can anybody help? These are time sensitive documents. For now, I may try opening them with my iPad, but wow, if I knew this was going to happen I certainly would not have updated. How do I install Adobe Flash player? Why isn't  generic?    Seems like Collection&lt;E&gt; could have boolean remove(E o);   Then, when you accidentally try to remove (for example) Set&lt;String&gt; instead of each individual String from a Collection&lt;String&gt;, it would be a compile time error instead of a debugging problem later. Forcing SSL and www in .htaccess I'm looking for a way to force SSL and www.  I've been able to force both separately but together I keep running into redirection issues. The following code works when handling a URL in this format: http://example.com and properly redirects to https://www.example.com but when the incoming URL is https://example.com it will not forward to https://www.example.com - Any suggestions?  EDIT: it should also send http://www.example.com to https://www.example.com.  RewriteCond %{REMOTE_ADDR} !127\.0\.0\.0 RewriteCond %{SERVER_PORT} 80 RewriteCond %{HTTP_HOST} !^www.example\.com$ RewriteRule ^(.*)$ https://www.example.com/$1 [R,L] I am a new user, who has just been told to run / execute a command. The answer has some text with a grey background like this text here or  sometimes this text here.   However, I don't know what "run" or "command" means in relation to Ubuntu.  How do I do this?    This is intended for use as a Q&amp;A you can link to when you tell someone to run a command. MySQL Access denied for user 'root'@'localhost' Thread Confinement Translation of words according to babel language I've got a template that is to be used in french or english, is there a name in babel defining the "of" of "page x of yy" than I want to translate automaticaly to "page x sur y"  If not, is there a way of setting a name according to language selected in babel. inequality with three variables and condition New passport and entrance Schengen I am from Brazil and travel a lot in Schengen countries. Under the rules of Schengen visa (3 months stay in a 6 months period). In my passport are the entrance and exit stamps, also to chec the days I stay in Schengen.  I need a new passport and will get this in Brazil. So in this new passport are NOT the stamps. Does this mean I start new with the Schengen visa rule? I seems like. The new passport is empty. Or do I miss something? It would be great because I am almost on my 90 days stay in the period of 180 days. Two paths that show that $\frac{x-y}{x^2 + y^2}$ has no limit when $(x,y) \rightarrow (0,0)$ In the LoTR movies (not sure if the books are the same) but when Gollum lost the ring to Bilbo decades ago in The Hobbit, he appeared to look the same and even move the same in The Fellowship of the Ring. Bilbo on the other hand, seemed to have aged very rapidly when he passed the ring to Frodo. When Frodo met up with Bilbo in Rivendell shortly after his quest began, Bilbo appeared much older and even more much slower.  I realize that Gollum had the ring for much longer than Bilbo, but wouldn't him losing the ring have the same effect as it had on Bilbo? Retrieve active locale in Grails application $\sqrt{c+\sqrt{c+\sqrt{c+\cdots}}}$, or the limit of the sequence $x_{n+1} = \sqrt{c+x_n}$ Search across Stack Exchange sites in Android app Is it possible to search for a question across all Stack Exchange sites in the Android app?   Right now I can search in only one specific site at a time.   If not, can you add that feature?