Sending data from Activity to Fragment: NPE
What is a NullPointerException, and how do I fix it?
Replace Tag of and xml file after pattern matching using shell I have an input xml file like below INPUT FILE &lt;ReconSummary&gt; &lt;entryName&gt;Total Deep&lt;/entryName&gt; &lt;Code&gt;777&lt;/Code&gt; &lt;License&gt;L&lt;/License&gt; &lt;Tran&gt;H20&lt;/Tran&gt; &lt;job&gt;1234&lt;/job&gt; &lt;/ReconSummary&gt;   &lt;ReconSummary&gt; &lt;entryName&gt;Total Saurav&lt;/entryName&gt; &lt;Code&gt;666&lt;/Code&gt; &lt;License&gt;L&lt;/License&gt; &lt;Tran&gt;H20&lt;/Tran&gt; &lt;job&gt;1234&lt;/job&gt; &lt;/ReconSummary&gt;   &lt;ReconSummary&gt; &lt;entryName&gt;Total Ankur&lt;/entryName&gt; &lt;Code&gt;555&lt;/Code&gt; &lt;License&gt;L&lt;/License&gt; &lt;Tran&gt;H20&lt;/Tran&gt; &lt;job&gt;1234&lt;/job&gt; &lt;/ReconSummary&gt;  I want to comment the tag if i find the pattern &quot;Total Deep&quot; so that the output file looks like below OUTPUT &lt;!--&lt;ReconSummary&gt; &lt;entryName&gt;Total Deep&lt;/entryName&gt; &lt;Code&gt;777&lt;/Code&gt; &lt;License&gt;L&lt;/License&gt; &lt;Tran&gt;H20&lt;/Tran&gt; &lt;job&gt;1234&lt;/job&gt; &lt;/ReconSummary&gt;--&gt;   &lt;ReconSummary&gt; &lt;entryName&gt;Total Saurav&lt;/entryName&gt; &lt;Code&gt;666&lt;/Code&gt; &lt;License&gt;L&lt;/License&gt; &lt;Tran&gt;H20&lt;/Tran&gt; &lt;job&gt;1234&lt;/job&gt; &lt;/ReconSummary&gt;   &lt;ReconSummary&gt; &lt;entryName&gt;Total Ankur&lt;/entryName&gt; &lt;Code&gt;555&lt;/Code&gt; &lt;License&gt;L&lt;/License&gt; &lt;Tran&gt;H20&lt;/Tran&gt; &lt;job&gt;1234&lt;/job&gt; &lt;/ReconSummary&gt;  Since i am new to shell scripting, can anyone help me out as to how i can apply this with the help of shell scripting? Is there a term for this word play where a song intentionally avoids completing a rhyme? Take this for example:  In this , at 1:04 to 1:10, the person goes on rapping with a rhyming word at the end of each line, but he pauses before the end of the last word and, being humans, we predict the next word (due to the hint from the rhyme) that he is going to say but he avoids it intentionally. Is there a word or phrase for this word play?     ...and the beat still knocks when I sort my socks   I'm five foot eleven of sex   from the tip of my head to my gorgeous...   knees    Not the best example I could find but I think it sums up my point quite well. Ckeditor toolbar not entirely showing up Why are effect size estimates (such as $R^2$) difficult in mixed-effects models? How to create posters using LaTeX I want to create posters for my poster presentation on a conference. What tools or LaTeX classes are available for preparing posters ? Bash File Unable to locate package when new line is added When building a bash file to execute I keep getting an error after adding a new line. I have tried moving some lines around or removing some of the packages but it will results in the same error. In the file if I was to remove 3 and 4 it there will no longer be an error.   E: Unable to locate package &lt;package&gt;   The bash file looks like this   #!/usr/bin/env bash sudo apt update &amp;&amp; sudo apt install -y python3-pip build-essential python3-dev python3-setuptools gcc sshpass sudo apt-get install apt-transport-https lsb-release software-properties-common dirmngr sudo apt-get update   The output with the error  Hit:1 http://us.archive.ubuntu.com/ubuntu bionic InRelease Get:2 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]                                                   Hit:3 http://archive.ubuntu.com/ubuntu bionic InRelease                                             Get:4 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]         Get:5 http://us.archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]                                       Fetched 252 kB in 1s (189 kB/s)     Reading package lists... Done Building dependency tree        Reading state information... Done All packages are up to date. Reading package lists... Done Building dependency tree        Reading state information... Done E: Unable to locate package sshpass Reading package lists... Done Building dependency tree        Reading state information... Done E: Unable to locate package dirmngr Hit:1 http://us.archive.ubuntu.com/ubuntu bionic InRelease Get:2 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]                                                   Hit:3 http://archive.ubuntu.com/ubuntu bionic InRelease                                             Get:4 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]         Get:5 http://us.archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]                                       Fetched 252 kB in 1s (209 kB/s)     Reading package lists... Done What does the double slash mean in `${f// /_}`? I'm learning Bash, and I want to replace space characters with other "non blank" characters. I'm using a for loop:  for f in *\ *; do mv "$f" "${f// /_}"; done   My question is, why are the double slash and the space in ${f// /_}? What does ${f// /_} do? Surfing the web anonymously What is the best, fastest, safest way to surf the web anonymously, and how much anonymity can you really achieve? How to send variable to an inline shell-script? How $\frac{1}{n}\sum_{i=1}^n X_i^2 - \bar X^2 = \frac{\sum_{i=1}^n (X_i - \bar X)^2}{n}$ How   $\frac{1}{n}\sum_{i=1}^n X_i^2 - \bar X^2 = \frac{\sum_{i=1}^n (X_i - \bar X)^2}{n}$   i have tried to do that by the following procedure:  $\frac{1}{n}\sum_{i=1}^n X_i^2 - \bar X^2$  =$\frac{1}{n}(\sum_{i=1}^n X_i^2 - n\bar X^2)$  =$\frac{1}{n}(\sum_{i=1}^n X_i^2 - \sum_{i=1}^n\bar X^2)$  =$\frac{1}{n} \sum_{i=1}^n (X_i^2 - \bar X^2)$  Then i have stumbled. I have been facing hard time understanding meaning of "random sample" as well as "iid random variable". I tried to find out the meaning from several sources, but just got more and more confused. I am posting here what I tried and got to know:  Degroot's Probability &amp; Statistics says:     Random Samples / i.i.d. / Sample Size : Consider a given probability distribution on the real line that can be represented by either a p.f. or a p.d.f. $f$. It is said that $n$ random variables $X_1 , . . . , X_n$ form a random sample from this distribution if these random variables are independent and the marginal p.f. or p.d.f. of each of them is $f$. Such random variables are also said to be independent and identically distributed, abbreviated i.i.d. We refer to the number n of random variables as the sample size.   But one of the other statistics book I have says:       In a Random Sampling, we guarantee that every individual unit in the population gets an equal chance(probability) of being selected.   So, I have a feeling that i.i.d.s are elements that construct random sample, and the procedure to have random sample is random sampling. Am I right?   P.S.: I am very confused about this topic, so I will appreciate elaborate reply. Thanks. How to show TCP listenings and filter them by local IP on Windows? Server has numerous IP addresses, set up on it's network interface.  How to find, who is listening to specific IP port 80?  netstat shows very long list. Are there any builtin means?  UPDATE  Also can't use findstr with also wishing to know process name because brocess name is displayed on separate line. How can I return NULL from a generic method in C#? Is the total energy of the universe zero? This is an exercise from Chapter 3 of Golan's linear algebra book.  Problem: Show $\mathbb{Z}$ is not a vector space over a field.  Solution attempt:  Suppose there is a such a field and proceed by contradiction. I will write multiplication $FV$, where $F$ is in the field and $V$ is an element of $\mathbb{Z}$.   First we rule out the case where the field has characteristic 2. We would have   $$0=(1_F+1_F)1=1_F1+1_F1=2$$  a contradiction.  Now, consider the case where the field does not have characteristic 2. Then there is an element $2^{-1}_F$ in the field, and   $1=2_F(2^{-1}_F1)=2^{-1}_F1+2^{-1}_F1$  Now $2^{-1}_F1\in\mathbb{Z}$ as it is an element of the vector space, but there is no element $a\in\mathbb{Z}$ with $2a=1$, so we have a contradiction.  Is this correct? How do I enter a file or directory with special characters in its name? I want to enter the following folder in the terminal:  Milano, Torino (Jan)-Compressed   How should I write the command cd to enter this directory?  Spaces and several other special characters like \, *, ), ( and ? cause problems when I try to use them in the command line or scripts, e.g.:    $ cd space dir bash: cd: space: No such file or directory  $ cat space file cat: space: No such file or directory cat: file: No such file or directory  $ cat ( bash: syntax error near unexpected token `newline'  $ echo content &gt;\ &gt; ^C  $ ls ? (  )  *  ?  \   How do I enter file or directory names that contain special characters in the terminal in general? When installing an application, the application lists permissions that it needs to perform its  functions.    I am creating this list of the the system defined permissions and a description of what they mean. It is a community wiki so if new permissions are added in the future they can be added to this list. image of polynomial map is not an algebraic set I am doing an exercise about algebraic geometry, where the exercise  tell us to provide example of the image of polynomial map $f:\mathbb{C}^{m}\rightarrow \mathbb{C}^{n}$ that is not an algebraic set. But I am thinking that the image of every polynomial is $\mathbb{C}$ thus every polynomial map is surjective. What have I misunderstand? Choosing C++ debugger on linux What determines who gets or becomes an MVP? This hasn't been asked yet, but what determines how or who gets an MVP award in CS:GO? After a match, there's always a little blurb that first states who got MVP first, and then a random fact (Player X got Y knife kills, Player X lasted Y rounds without dying, etc.).  Do these two factors both "factor" into getting an MVP award? Is it a set percentage of enemies you kill? Is there a priority list (ie, planting bomb, defusing, etc.)?