How can I secure my PHP queries against SQL injection without using PDO or prepared statements? i want to secure my sql queries without pdo or prepare statement can this function do ?  function sql_escape($string) {     $string =   iconv(mb_detect_encoding($string),'UTF-8//IGNORE',$string);     $string =   addslashes($string);     $string =   preg_replace('/[\x00-\x1F\x80-\xFF\0xB4\0x60\0x96\0x97\0x95\0x94\0x93\0x92\0x91\0x84\0x82\0x3B\0x8A]/', '', $string);     $string =   addslashes($string);     return $string; }
How can I prevent SQL injection in PHP? If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?
Could anyone tell me what is up with so many archives, and how are they differ?  There's at least five that I can think of, .tar.tz, .tar.gz, .tar.bz2, .tar.lz, .tar.z  Which is best for what applications? It just seems silly to make so many variations of the same file but I'm sure there's a reason. Galois group of irreducible cubic equation The polynomial $f(x) = x^3 -3x + 1$  is irreducible, and I'm trying to find the splitting field of the polynomial.  We've been given the hint by our lecturer to allow an arbitrary $\alpha$ to be a root and then to check that $\alpha$ is a root, then $2-\alpha^2$ is also root. I've done this with no problem.  My issue is since this is a polynomial of degree $3$, there must be another root that is somehow related to $\alpha$ so that I can create the splitting field and in turn the Galois group of my polynomial but I have no idea what this last root could be. How do I see all foreign keys to a table or column? In MySQL, how do I get a list of all foreign key constraints pointing to a particular table? a particular column? This is the same thing as , but for MySQL. Can multiple different HTML elements have the same ID if they're different elements? Round a double to x significant figures Python Script to Add Fields to Feature Classes I have to try to add a field called 'Name' to a bunch of different feature classes using python, and then access the name of the feature class to fill in the field. I have no idea how to even start this! I know I need a loop but that's all I know. How do I compute the principal value of a these complex numbers? I have 2 examples I'm not sure how to calculate One being $$\frac{1}{(1+i)^i}$$ the other is $$(-1+i\sqrt{3})^{1+i}$$ Can anyone help please? Anything appreciated I accidentally unset all the directories of $PATH while trying to add a new one in ~/.bashrc. I opened a new terminal window as I was editing and now $PATH is empty. I'm worried if I boot from another drive to find the $PATH I won't be able to boot into this drive again.  Basically, what is the default result of echo $PATH? Solving $x^3-y^3=xy+61$ in integers I'm trying to solve the following equation:  $$x^3-y^3=xy+61$$  I got:  $$(x-y)(x^2+xy+y^2)=xy+61$$  But I can't go any further. I am looking for a solution in integers.  I need some hints to proceed, please! Morphing only a part of a full path in tikz This might be a tikz newbie question but I have some trouble solving this.  I want to draw and fill a rectangular path where path morphing should be applied only to the upper side of the shape, more specifically I want to have an upper part with random steps. The rest of the path (left, lower and right sides) should just be straight lines. The shape should be closed and filled with one color.   My problem is that I cannot figure out how to apply the morphing only to the upper side and I suppose I cannot break up the path into different subpaths since I want to fill the final shape. Is there a way to use the morphing only on a part of the full path? Another problem is that the cycle command does not really close the shape at the upper left corner.  I tried to find a solution in the tikz manual but there was nothing that really helped me.  Here is some example code:  \documentclass[tikz, border=10pt]{standalone} \usepackage{tikz}  \begin{document}  \usetikzlibrary{decorations.pathmorphing} \begin{tikzpicture}  \draw[decorate, decoration={random steps,segment length=3.0mm, amplitude=2.0mm}, thick, rounded corners=1ex, fill=brown!70] (0,0) -- (4,0) -- ++(0, -1) -- ++(-4,0) -- cycle;   \end{tikzpicture} \end{document} I came to this conclusion: the primes that can't be written as the sum of two squares (lets use$p\prime$ to denote) can be written as ${p}\prime \equiv 3 \;(\bmod\; 4)$.  I need a simple proof to show this and am stuck. I would appreciate guidance! According to , $[0,1]$ cannot be written as union of countable disjoint closed sets, is the same true about (uncountable) family of disjoint closed intervals ? What do the symbols displayed by ls -F mean? I noticed that if I run ls -F on a directory, some of the entries have a * or a @ after them.   spuder@ubuntu:~$ ls -F /sbin acpi_available*   getpcaps*           lvmconf*                 ntfscp*        start-stop-daemon* agetty*           getty*              lvmdiskscan@             ntfslabel*     status@ alsa*             halt@               lvmdump*                 ntfsresize*    stop@ alsactl*          hdparm*             lvmsadc@      spuder@ubuntu:~$ ls -F ~ daq-0.6.1/  examples.desktop       noname-cache.lib  snort-2.9.1/   Templates/ Desktop/    jpgraph-1.27.1/        noname.sch        snortfiles/    Ubuntu One/ Documents/     According to the ls man pages   spuder@ubuntu:~$ man ls ... -F, --classify   append indicator (one of */=&gt;@|) to entries ...   I'm guessing that @ means symbolic link,     What do these other indicators mean ( */=&gt;@| )  ? What about lowering the edit character limit for characters in code snippets? , to correct a misspelled library enum in an answer. Since the edit was only one character, I also had to add a superfluous sentence to get over the character limit required to edit a post.  I've hit this problem before in other edits, always in code snippets. Since the edit limit exists to prevent trivial edits, and since there are many cases where one character code edits are not trivial (= to == etc), would it make sense to have a lower edit minimum inside code snippets? How to install the latest stable version of Chromium? Is there an easier way to install Chromium than what is described ?  Furthermore, is there an easier way to stay up to date with current Chromium releases rather than having to re-build Chromium each release? (a script which automatically grabs and installs the latest build possibly?).  Related: What is a tensor? I have a pretty good knowledge of physics, but couldn't deeply understand what a  is and why it is so fundamental. Is it possible to use the Lagrangian formalism involving physical terms to answer the question of why all planets are approximately spherical?  Let's assume that a planet is 'born' when lots of particles of uniform density are piled together, and constrained only by the Newtonian gravity of the $N$ particles with no external gravity.    My question is: Is it possible to use the variational calculus starting from this situation to prove that planets should be spherical? How to get my own IP address and save it to a variable in a shell script? C++ catching all exceptions Is Using Digital Signatures to prove identity a zero knowledge proof? Suppose Alice publishes a book with a public key in it, and later wants to prove that she wrote the book. She could sign challenge messages with her private key, and others could verify those signed messages. Alice is proving she knows a private key without revealing anything about it.  Is this an example of an interactive zero knowledge proof?   Or does this example somehow not apply to zero knowledge proofs?