I'm fairly new on PHP. I'm trying to sanitize my input before UPDATE it on myqsql. If my string is something with apostrophe, like  &quot; I'm new on Php&quot; it not works with this code $description = $_POST['description'];  $description = htmlspecialchars($description);  $description = mysqli_real_escape_string($description);  $description = trim(preg_replace('/\s+/', ' ', $description));  It didn't work: my field in table result empty If i use $description = $_POST['description'];  $description = htmlspecialchars($description);  $description =  str_replace(&quot;'&quot;,&quot;\'&quot;, $description);  $description = trim(preg_replace('/\s+/', ' ', $description));  It works. Why  $description = mysqli_real_escape_string($description) won't work ?
Is there a catchall function somewhere that works well for sanitizing user input for SQL injection and XSS attacks, while still allowing certain types of HTML tags?
Where to find Birth and Death Records for Bucharest, Romania? My husband's family came from Bucharest. Specifically his mother was born in Sibiu.  I have been able to piece together names and relations of several grand and great grandparents from word of mouth and some fortunate pictures they had of the cemetery in Sibiu.  I cannot however find any records of birth's and death's for any of them.   Are there sites or organizations that hold records for Romania? What is the difference between weight and mass? How do I get a straight quote instead of curly quotes? I’m not inside verb or listing or any other special environments, and I’m not using XeLaTeX or anything—just normal LaTeX. I don’t want to change all quotes, just get the occasional straight quote. For example, I’d like a way to get something like this in the TeX:  ... some examples of these glyphs are curly quotes (``''), straight quotes ('"), and angled quotes ($'$$"$) ...   to look like this in the output:  ... some examples of these glyphs are curly quotes (“”), straight quotes ('"), and angled quotes (′″) ...   As I’m using an academic-publisher-provided template that does its own required font setup, I’m extremely wary of changing fonts or font encodings. I think the template uses the times package, and the formatting instructions say all fonts must be Type 1. If you copy the contents of   httpd.conf   and then paste it into a cat command.. such as this one..  #!/bin/bash cat &gt; /test &lt;&lt; EOF pasted here.. EOF   you run into this error:  -bash: command substitution: line 1: unexpected EOF while looking for matching `'' -bash: command substitution: line 4: syntax error: unexpected end of file   perhaps the solution is to escape the dollar signs and maybe even quotes and so on..  but given that this is such a large file.. can dollar signs be automatically be escaped ?  is my only option to escape them via another program and then give it to the cat command ? When is the finalize() method called in Java? On every boot up I get this:    For about 10 seconds (or more) before the "normal" Ubuntu Gnome loading screen and the login screen comes up.  I've read some questions and a bug report about this already, but this problem was dismissed as a minor inconvenience or there were no real solutions (that worked for me). For me, this problem leads to an unacceptable slow boot compared to Ubuntu (Unity) or Windows.  Does anybody know how to fix this or is this a "feature" of Ubuntu Gnome and not a bug? What is the rough estimate of salary value for a taxpayer to pay AMT? For US federal tax, whether a taxpayer is subject to AMT is determined by a complicated way in Instructions for Form 1040, Line 45, which involves an incomprehensible "worksheet to see if you should fill in form 6251".  By simplification and approximation, is there a rule of thumb for an estimate of a salary value of a taxpayer, so that a salary above the value might cause the taxpayer to pay AMT with a big possibility, and a salary below the value might not with a big possibility?  Why do the following two sources seem to differ greatly in estimates of the boundary salary value:    says that  the possible boundary salary value for a single taxpayer  to pay AMT is $53,900.  says that      Taxpayers with small incomes fall within the AMT exemption limits.   That leaves the upper middle class to face the tax, especially those   with incomes between $200,000 and $500,000    Thanks. According to the , you can harden a MySQL server by adding passwords, or removing the anonymous accounts.      If you want to prevent clients from connecting as anonymous users   without a password, you should either assign a password to each   anonymous account or else remove the accounts.   Before hardening, my users table looked like this.   mysql&gt; select user,host,password from mysql.user; +------------------+-----------+-------------------------------------------+ | user             | host      | password                                  | +------------------+-----------+-------------------------------------------+ | root             | localhost | *F3A2A51A9B0F2BE246XXXXXXXXXXXXXXXXXXXXXX | | root             | gitlab    |                                           | | root             | 127.0.0.1 |                                           | | root             | ::1       |                                           | |                  | localhost |                                           | |                  | gitlab    |                                           | | debian-sys-maint | localhost | *95C1BF709B26A5BAXXXXXXXXXXXXXXXXXXXXXXXX | | myuser           | localhost | *6C8989366EAF75BB6XXXXXXXXXXXXXXXXXXXXXXX | +------------------+-----------+-------------------------------------------+   I've remove all anonymous accounts, so that the user table now looks like this.  (I'm using puppet to manage the users, but puppet effectively performs a DROP USER command).   mysql&gt; select user,host,password from mysql.user; +------------------+-----------+-------------------------------------------+ | user             | host      | password                                  | +------------------+-----------+-------------------------------------------+ | root             | localhost | *F3A2A51A9B0F2BE246XXXXXXXXXXXXXXXXXXXXXX | | debian-sys-maint | localhost | *95C1BF709B26A5BAXXXXXXXXXXXXXXXXXXXXXXXX | | myuser           | localhost | *6C8989366EAF75BB6XXXXXXXXXXXXXXXXXXXXXXX | +------------------+-----------+-------------------------------------------+   Why is it that I am still able to login to my test system without a username or a password? What do I need to do to prevent any unwanted users from logging in?   root@gitlab:~# mysql Welcome to the MySQL monitor.  Commands end with ; or \g. Your MySQL connection id is 98 Server version: 5.5.32-0ubuntu0.12.04.1 (Ubuntu) .... mysql&gt;    Update:  I've also just discovered that I can login as root, without entering a password.  Update2: I found  which has some good information, but does not solve the issue.   There are no anonymous users.  mysql&gt; select user,host,password from mysql.user where user=''; Empty set (0.00 sec)   I login as root@localhost.  mysql&gt; select USER(),CURRENT_USER(); +----------------+----------------+ | USER()         | CURRENT_USER() | +----------------+----------------+ | root@localhost | root@localhost | +----------------+----------------+    I do not have a default password, or skip-grant-tables defined in my.cnf  root@gitlab:~# cat /etc/mysql/my.cnf |grep -i 'skip-grant-tables'|wc -l 0 root@gitlab:~# cat /etc/mysql/my.cnf |grep -i 'pass'|wc -l 0   Update3:  I have tried performing these steps with puppet, (which should perform a flush privileges automatically). I have also manually flushed privileges and also tried restarting mysql.   Update4: I've also tried changing the mysql root password and flushed privileges. No luck, I can still log in as any user without a password. number of prime ideals in algebraic integers I encountered The Squirrel at "A tree."              |   |                                                                         |   |                     "   Hello, I'm The                        |             |                        Squirrel. I can                        |             |                      provide you candies,                     |             |                      and lots of things.                                    |                      I know how much you                                    |        _.-'''-,      love candies. But I                                    |      .'        `\     feel alone in this                                    |     /           /          forest.       "                         |        |    /      .--^_^                                                   |        |    |     /  C ,,\                                                           |    |    |   \  _.)                           ___                            |     \   |   /  \                   ____.----'.-'                            |      '-, \./ \)\)               .-' --  __.-'                   |            \        `-/   );/           ___/  - _.-'                        |             \_________''--'-'________.-' --    /                            |              -   --        -  -     -     __.-'                                              -    --    -     --   --  /                                                 _________________________.-'                                 He asks you some questions. What are the correct answers, and what is the reward for getting them correct? This error occurs whenever I try to work with sudo. I changed the permissions of /var/ folder to 777 and I think this causes the error. Please help me get back a functional sudo and /var. If $A$ is a square matrix and $A^2 = 0$ then $A=0$. Is this true? If not, provide a counter-example. This is a proof question and I am not sure how to prove it. It is obviously true if you start with $A = 0$ and square it.   I was thinking:  If $ A^2 = 0 $  then $ A A = 0 $  $ A A A^{-1} = 0 A^{-1}$  $I\,A = 0 $   but the zero matrix is not invertible and that it was not among the given conditions.  Where's a good place to start? Can I travel to Canada with valid visa on old/expired passport? I recently renewed my passport. I also have an expired passport which has my Canada visa (visitor's) valid for another three years. I have already used my Canadian visa which is multiple entry. I am planning to visit Canada this summer.  Since my valid Canadian visa is in my old/expired passport, do I need to renew/transfer my Canada visa or can I simply travel with valid visa in old passport? Why does my Nikon D3100 give the error "Lens not attached" with a Vivitar 200 telephoto lens? I have a Nikon D3100 camera, and am trying to use an "Automatic Fixed Mount Vivitar 200mm lens" with it. When I attach the lens, I get the message "Lens not attached". and nothing works. HELP!  I can't easily take it to a camera shop, as I live in the Mojave Desert, about 200 miles away from any camera shop. This is a new lens, and a new camera. This was a question my friend found in a book.  A block attached to a spring pulled by a constant horizontal force is kept on a smooth horizontal surface. Initially the spring is in its natural state. Then the maximum work that the applied force F can do is:  (a) $F^2/k$ (b) $2F^2/k$ (c) $4F^2/k$ (d) $F^2/2k$  My friend thought that the answer is (a) since the maximum displacement is $x=F/k$ and $W=Fx=F^2/k$. But he saw that the book's answer is different and he asked this question to me. I at first thought that the answer will be (a), but then I realised that this situation is somewhat similar to a charging capacitor. The final energy of the spring is actually $\frac12kx^2=F^2/2k$. So probably the answer is (d)? But the work done is still (a)? But the book says neither. It's (b). This is the logic in the book:  Method 1: in the book:  $$Fx=\frac12kx^2$$  $$x=2F/k$$  $$W=\frac12kx^2=2F^2/k$$  (since the book is an objective questions book it did not have detailed explanations)  What is wrong in the following methods?  Method 2: by calculating the maximum displacement  $$x=F/k$$  $$W=Fx=F^2/k.$$ Method 3: by calculating the final energy  $$x=F/k$$  $$\frac12kx^2=F^2/2k$$  PS: We both know calculus so don't hesitate to use it in the answers. The site description in the hero header is wrong for Meta sites The hero header contains the same description for the Main and Meta sites. Here's the one for MSO:           Meta Stack Overflow is a question and answer site for professional and enthusiast programmers. Join them; it only takes a minute:    This can easily confuse people who are new to the network, so I feel this should be changed to something Meta specific. Perhaps re-use the text from the sidebar, that has a good description:     This site is intended for bugs, features, and discussion of Stack Overflow and the software that powers it. You must have an account on Stack Overflow to participate. Finding limit of a sequence in product form \begin{equation} \prod_{n=2}^{\infty} \left (1-\frac{2}{n(n+1)}  \right )^2 \end{equation}  I need to find limit for the following product..answer is $\frac{1}{9}$.  I have tried cancelling out but can't figure out.  Its a monotonically decreasing sequence so will converge to its infimum.. how to find the infimum? Existence of irreducible polynomials over finite field Let $F$ be a finite field. How do we prove that for each $n \in \mathbb{N}$ there is an irreducible polynomial of degree $n$?  One can assume that $F = \mathbb{F}_{p^m}$ where $p$ is prime. If $n \ge |F|$ then I can construct an irreducible polynomial, namely  $ p(x) = 1 + \prod_{j=1}^{|F|} ( x - a_j )$  where $a_j$ are all the field elements. It is clear that $p(x)$ has no roots in $F$.  This trick doesn't work for $n &lt; |F|$. A counter-example: Let $F = \mathbb{F}_3$ and $p(x) = 1 + (x-1)(x-2)$, then $p(1) = 1$, $p(2) = 1$, $p(0) = 1 + (-1)(-2) = 1 + 2 = 3 = 0 \pmod 3$.  I know there is a way to count them using the Möbius function $\mu(n)$ but I want a proof without it that just shows existence. Here is the documents needed.     Here are the documents needed.       Which is grammatically correct and why? My guess would be the second one because of the plural form. Can someone explain how combinatorial proofs work?  I've included an example questions that's been giving me a hard time.  Any insight on the topic would be great.  $$\sum_{k=1}^{n}k{n \choose k} = n2^{n-1}$$  Another one:  $${2n \choose 2} = 2{n \choose 2} + n^2$$  The solution says:  LHS: Pick two people from a pool of n men and n women. RHS: Pick two women, pick two men, and pick one of each.  But I don't see how this applies.  How does $n^2$ show that we're picking "one of each?"  Thanks for the help :)