How to backup created symlinks?
How to backup symbolic link paths?
$\gcd(a,b,c)=\gcd(\gcd(a,b),c)\,$ [GCD Associative Law] I have a file with a number of lines in a file filename.  I want to count how many lines start with character 'a', with 'b' and so on in one go.  What command i should execute.? I have a LAMP server with following configuration.  CPU : Intel(R) Xeon(R) CPU   RAM : 32 GB  HDD : 80 GB  Running on virtual environment.  All the things in the server are running smoothly. But I have noticed that the RAM usage is the server is increasing each day without any reason.   This is the current memory usage on my server.  # free -g              total       used       free     shared    buffers     cached Mem:            31         13         17          0          0         10 -/+ buffers/cache:          1         29 Swap:            2          0          2   And you can see the last 8 weeks memory usage below.   And i have executed the following command to find how much memory each process is consuming.  # ps -eo size,pid,user,command --sort -size | awk '{ hr=$1/1024 ; printf("%13.2f Mb ",hr) } { for ( x=4 ; x&lt;=NF ; x++ ) { printf("%s ",$x) } print "" }'          0.00 Mb COMMAND        2253.62 Mb /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --pid-file=/var/run/mysqld/mysqld.pid --skip-external-locking --socket=/var/lib/mysql/mysql.sock        1171.66 Mb java -jar /etc/vmagent/bin/VMAgent.jar         138.27 Mb /sbin/audispd         127.75 Mb /usr/sbin/named -u named -c /etc/named.conf -u named -t /var/named/run-root          74.29 Mb auditd          73.03 Mb automount          43.14 Mb /usr/bin/spamd --username=popuser --daemonize --nouser-config --helper-home-dir=/var/qmail --max-children 5 --create-prefs --virtual-config-dir=/var/qmail/mailnames/%d/%l/.spamassassin --pidfile=/var/run/spamd/spamd_full.pid --socketpath=/tmp/spamd_full.sock          43.14 Mb spamd child          43.14 Mb spamd child          37.13 Mb /usr/sbin/httpd          37.02 Mb /usr/sbin/httpd          36.52 Mb /usr/sbin/httpd          36.46 Mb /usr/sbin/httpd          36.23 Mb /usr/sbin/httpd ................   For troubleshooting , i have restarted the MySQL and APACHE servers. But the result was same. Restarting the entire server will fix the issue, but i want to know what is the real issue.  Let me know if you have any idea about this issue.  Thanks,  Arun S Solve for $x$: $2^x=4x$ Given that $x$ is a positive integer. By using methods of trial and error as well as plotting two lines: $y=2^x$, $y=4x$ on a graph and find their intersection point, we can easily solve for $x$ which is equal to 4. However, I do not know how to solve this using only equation. Can anyone help me? Drop "not constructive", combine "noisy", reword "rude" and "other" comment flags What's the default value for an 'object' in java? If $A$ commutes with $B$ and $B$ commutes with $C$, then $A$ commutes with $C$ Let $A,B,C \in \ M(3,\mathbb{R})$ be such that $A$ commutes with $B $and $B$ commutes with $C$. $B$ is not scalar matrix. Then, $A$ commutes with $C$.   Is this true or false? I think it is not true, but cannot think of a counterexample. Any suggestions? Difficult variation of the committee problem Concatenating string with space What are the advantages/disadvantages of the new encryption feature in ubuntu 13.10 I'm in the middle of installing 13.10 and the Ubuntu page I was following on how to install from a USB stick says nothing about these two choices (on the Installation type screen):     1) Encrypt the new Ubuntu installation for security (you will choose a security key in the next step).      2) Use LVM with the new Ubuntu installation (this will set up Logical Volume Management. It allows taking snapshots and easier partition resizing)   I'm a writer using the computer for mostly writing ebooks but I also do all the things most people do: buy stuff online, online banking etc. I want my information to be safe but I don't want to overburden my system with security stuff either. And I've read a lot of the similarly themed questions here on the forum but they've all been about stuff more technical than I'm concerned about.   Can somebody please just tell me in real layman's terms about the implications of these two choices? Thank you. Let $A$ be a closed and bounded subset of $\mathbb{R}^{n}$. Given that $f: A \to A$ satisfies $d(f(x),f(y)) &lt; d(x,y)$ for all $x,y \in A$, $x\neq y$ where $d$ is the usual Euclidean metric. Show that $f$ has a unique fixed point.    My observations:    Since $\mathbb{R^{n}}$ is complete, then $(A,d)$ is complete since $A$ is closed; Since $A$ is bounded, then $A \subset B_{R}$ for some $R &gt; 0$; Banach Fixed Point Theorem guarantees a unique fixed point if $f$ is contraction on $A$.   Please correct me if I am wrong. My quandry here is showing that $f$ is a contraction, i.e.  $$ d(f(x),f(y)) \leqslant k\cdot d(x,y), \hspace{3mm} k \in (0,1) $$  I'm looking for some hints or tips. Thank you. Whenever I add a Quick Smoke effect, I can't preview it on the viewport unless I bake it.   And Yes, I added the Smoke Domain on the object.   I've seen tutorials like this  and this  that clearly shows the possibility of previewing the smoke before baking it.   I'm using Blender on a Mac with AMD GPU. I would guess that this is something related to OpenGL, as thoroughly explained here -  but that's for Windows.   Does anyone have any idea how to fix this? How can I escape special HTML characters in JSP? Why people think dark matter as a massive particle? Couldn't it be gravitational waves? Dark matter is said to be present in the galaxies which helped galaxies to exist in the first place forming the glue to attach all the matter in the galaxies.  Given that dark matter never been seen or detected and only effect of which could be felt why do we believe it would be a particle? We have universe (almost) equally distributed in all directions with dark matter forming the skeleton for all the matter that could be seen. Can the dark matter be a illusion of gravitational waves interfering with each other forming this uniform interference pattern of galaxies/matter that is seen by us?  That would also explain the repulsive dark energy which would be the troughs in the gravitational waves indicating desructive interference in the gravitational waves.  Can we hope to simulating the above to come to the possible conclusion of source(two or many) of these gravitational waves that could give rise to skeleton of dark matter and dark energy which may be present in some higher dimentions? When does the placement of a resistor matter? I've been a programmer for years but am very new to electronic engineering. So far I see people saying it doesn't matter where a resistor goes in your LED circuit as long as it is present, but it sounds like that's the nature of the basic LED circuit.  When does the placement of a resistor start to become important? How can I randomize order of elements in a list? Where can I have a genuine Ainu cultural experience in Hokkaido? During my next trip to Japan I may end up in Hokkaido. I've read something about this mysterious indigenous group called Ainu/Aynu/Aino/Ezo, but I must admit my understanding of the whole thing is rather limited right now.   What I wish to know is: is there such a thing like an authentic Ainu village/town/whole-region where Ainu people live according to their tradition, as opposed to something staged for tourists?  Edit: given the comments below I wish to specify better what I mean with the word 'authentic'. Of course, I don't expect pristine landscapes and Ainu people living in blissful harmony with fluffy penguins (semi-quote) but I won't be surprised to find out there still are authentic villages in remote areas of Hokkaido where mass tourism is not an issue at all.  People are subject to tourist's attention (tourist coming from different countries, at least) everywhere, not only when they "made a conscious decision to live a traditional life". This doesn't actually mean anything. Indian people are surprisingly differents (in local customs) from Italians and Italians take a lot of pictures during their travels there, still the tourism isn't banned in India. Scanning Java annotations at runtime What is the best way of searching the whole classpath for an annotated class?  I'm doing a library and I want to allow the users to annotate their classes, so when the Web application starts I need to scan the whole classpath for certain annotation.  Do you know a library or a Java facility to do this?  Edit: I'm thinking about something like the new functionality for Java EE 5 Web Services or EJB's. You annotate your class with @WebService or @EJB and the system finds these classes while loading so they are accessible remotely. If I run history, I can see my latest executed commands.  But if I do tail -f $HISTFILE or tail -f ~/.bash_history, they do not get listed.  Does the file get locked, is there a temporary location or something similar? Consider a sequence of $n$ Bernoulli trials with $P(\text{success})=p$. Let $X_i$ and $X_j$ be indicator variables of the number of "success" in $i$th and $j$th runs. Given the total number of success was $m$, $m&lt;n$. I am asked to compute the correlation coefficient for $X_i$ and $X_j$.  Now I know the formula for correlation coefficient, but to compute the co-variance I will need to find $E(X_i)$ and $E(X_j)$ first. By definition does $E(X_i)=p_i$ and $E(X_j)=p_j$? I feel this seems a bit too easy but I can't see whats wrong with it.