php
Post on 12-Sep-2014
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DESCRIPTION
Learn PHP basicsTRANSCRIPT
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PHP
Server Side Scripting Language
www.php.net
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What is the other side?
• JavaScript is the client side scripting language
• JavaScript is integrated within your browser
• It helps you do things on the user’s computer for e.g. form validation, simple calculation etc.
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Why is PHP so powerful?• Open Source and cross-platform• especially lightweight and speedy• can send HTTP headers
– set cookies– manage authentication– and redirect users
• excellent connectivity to many databases • integration with various external libraries
– to let you generate PDF documents– parse XML– create and modify images on the fly
• no need for a special development environment or IDE– You start a block of PHP code with <?php and end it with ?> – PHP goes right into your Web pages
• You don't have to declare variables before you use them• it's easy to create arrays and hashes (associative arrays) • A good rule of thumb for PHP: "When in doubt, try it; it will probably work."
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PHP history
• In 1995, when Rasmus Lerdorf started what was to become PHP, the only goal he had in mind was to find out who was reading his resume.
• Rasmus Lerdorf's original concept of creating tags within the HTML text for calling C code is revolutionizing the way dynamic Web applications are created.
• Though the code written by him has been revised and the scripting engine re-written from scratch. Still, the concepts and the inspiration for PHP came from Lerdorf's approach of finding practical and dynamic solutions that Web developers could use in their day-to-day work.
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PHPServer Side Scripting language
Dynamic Web Pages
Cookies
DataBase Support
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PHP Basics
• PHP meansPHP: Hypertext Preprocessor
• Escaping from HTML<?php . . . ?>
• StatementsYou use the semi-colon (;) at the end of the line
• CommentsPHP supports, C, C++ style comments./* C, C++ style multi-line comment */
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Basic Syntax• <?php
echo "Hello, World!";?>produces Hello, World!
• Variables are marked with a preceding $. You could write "Hello, World!" like this: <?php$message = "Hello, World!";echo $message;?>
• String concatenation is done with . (a period)• other arithmetic operators are what you would expect:
<?php$greeting = "Hello ";$num = 3 + 2;$num++;echo "$greeting $num people!";?> produces Hello 6 people!
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Single and double quote• Just as in Perl, a string surrounded with double quotes causes
variables inside it to be interpolated, but a string surrounded with single quotes does not. So,
• <?php$name = “Shantanu”;$greeting_1 = "Hello, $name!";$greeting_2 = 'Hello, $name!';echo "$greeting_1\n";echo "$greeting_2\n";?> produces Hello, Shantanu!
Hello, $name!• Note that the \n in the string turns into a new line, just as in Perl or in
C. This only works in double-quoted strings, however.
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Arrays
• You set off array indices (regular or associative) with square brackets ([ and ]): $fruit[0] = 'banana';$fruit[1] = 'papaya';
• A shortcut for creating arrays is the array()$fruit = array('banana','papaya');
• The built-in function count() tells you how many elements are in an array: $fruit = array('banana','papaya');print count($fruit); prints 2
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Arrays• Array index starts from 0• $a[0] = "first"; // a two element array
$a[1] = "second"; $a[] = "third"; // easy way to append to the array.// Now, $a[2] has "third"
• echo count($a); // prints 3• // create a hash in one shot• $myphonebook = array (• "sbabu" => "5348",• "keith" => "4829",• "carole" => "4533"• );• // oops, forgot dean! add dean• $myphonebook["dean"] = "5397";• // yeoh! carole's number is not that. correct it!• $myphonebook["carole" => "4522"• // didn't we tell that hashes and arrays are • //implemented alike? let's see• echo "$myphonebook[0]"; // sbabu• echo "$myphonebook[1]"; // 5348• Some functions useful in this context are sort(), next(), prev(), each().
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Environment Variables
• If the page "http://domain.com/company/test.php” contains the code <?phpecho "[$REQUEST_URI]";?> it prints out [/company/test.php]
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Custom Functions
• You can define your own functions as shown below. Return values can be any of the data types.
• function foo ($arg_1, $arg_2, ..., $arg_n) {• echo "Example function.\n";• return $retval;• }• Any valid PHP code may appear inside a
function, even other functions and class definitions. Functions must be defined before they are referenced.
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Custom Functions - Example
• <?• function AddFive ($TheNumber)• {• $TheNumberPlusFive = $TheNumber + 5;• print("$TheNumber plus 5 equals
$TheNumberPlusFive.<br>");• }• AddFive(15);• AddFive(23);• ?>
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Objects
• To create an object, use the new statement. • class foo {• function do_foo () { • echo "Doing foo."; • }• }• $bar = new foo;• $bar->do_foo();
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Classes• class Employee {• var $empno; // employee number• var $empnm; // name• function add_employee($in_num, $in_name){• $this->empno = $in_num;• $this->empnm = $in_name;• }• function show() {• echo "$this->empno, $this->empnm";• return;• }• function changenm($in_name){• $this->empnm = $in_name;• }• }• $sbabu = new Employee;• $sbabu->add_employee(10,"sbabu");• $sbabu->changenm("babu");• $sbabu->show();
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Guest Book Example• guest.htm
– A form where the site visitor will type his name and message.– Submit button will call the guestbook.php file.
• guestbook.php– open the guestbook.txt file– read old contents, add the new comment– display all comments to the browser– also add the new comment to the guestbook.txt file
• guestbook.txt– Starts with welcome message.– Keeps adding the comments added by users.– Don't forget to change the file permission from read to write once
uploaded to the server.
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guest.htm
• <body>• <form name="form1" method="post"
action="guestbook.php">• <input type="text" name="visitor"><p>• <textarea name="comment" rows="10"
cols="40"></textarea><p>• <input type="submit" name="Submit"
value="Submit">• </form>• </body>
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guestbook.php• <?• $file="guestbook.txt"; • $handle=fopen($file, "r+"); • $prevtext=fread($handle,filesize("$file")); • $new="<div align=\"center\"> Posted by:
<u><b>$visitor</b></u> <br> <p><font face=\"Fixedsys\"> $comment </font></p> <hr> </div>";
• $total = $prevtext . $new; • fclose($handle); • echo "$total"; • $handle=fopen($file, "w"); • fwrite($handle, $total); • fclose($handle); • ?>
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guestbook.txt
• <p>Welcome</p>
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Cookies
• To create and modify a cookie, use the PHP function setcookie(). setcookie() takes up to six arguments, depending upon how much control you want over the cookie and who can read its value.
• The simplest way of setting a cookie is like this:setcookie('name', 'bret');
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Add the following to the top of guestbook.php
• <?php• if (!$mevisit1){• @setcookie("mevisit1", "$visitor", time()+3600);• }• If ($mevisit1 != $visitor){• echo "hi $mevisit1!, we know you are not $visitor!!";• }• else {• echo "welcome back, $visitor";• …• }
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Variables through URL
• <html>
• <font color=<?php echo $mycolor; ?>>THis color is decided in the variable</font>
• </html>
• test.php?mycolor=blue
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Control Structure (If - Else)
• You can use the control structures if and elseif: if ($user_count > 200) {print "The site is busy right now!";} elseif ($user_count > 100) {print "The site is sort of active right now!"; } else {print "The site is lonely - only $user_count user logged on.";}
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Control Structure (while or for)
• To Print the following you can use looping structures such as for and while :I have eaten 4 bagels today.I have eaten 5 bagels today.I have eaten 6 bagels today.I have eaten 7 bagels today.
• $i = 4; while ($i < 8) {print "I have eaten $i bagels today.\n";$i++;}
• for ($i = 4; $i < 8; $i++) {print "I have eaten $i bagels today.\n"; }
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Control Structure (foreach)
• <?php• $month = array("January", "February", "March", "April", "May",
"June", "July", "August", "September", "October", "Novemeber", "December");
• echo "<FORM METHOD=POST ACTION = results.php>";• echo "<SELECT NAME=column_name >";• echo"<OPTION VALUE=\"/\">Pick a Month</OPTION>";• foreach($month as $MON)• {• echo "<OPTION VALUE=\"$MON\">$MON</OPTION>";• }• echo "</SELECT></FORM>";• ?>
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Switch• Switch is an elegant replacement for multiple if-elseif-else structure. • switch ($i) {• case 0:• print "i equals 0";• case 1:• print "i equals 1";• case 2:• print "i equals 2";• }• break, continue • break breaks out of current looping control-scructures. • continue is used within looping structures to skip the rest of the
current loop iteration and continue execution at the beginning of the next iteration.
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Mobile Handset Dealer’s website Example
• index.phpThe file with a drop down option.
• myfiles/photos.htmA html file with photos section.
• myfiles/products.htmA html file with products section.
• myfiles/printer.phpThis .php file will display the contents of the current page with the help of printer.css stylesheet.
• myfiles/normal.cssNormal stylesheet file.
• myfiles/printer.cssPrinter friendly stylesheet file.
• myfiles/A6188.gif
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Index.php1. <HTML>2. <HEAD>3. <LINK rel="stylesheet" type="text/css" href="include/normal.css">4. </HEAD>5. <BODY>6. <FORM name="infosys">7. <SELECT size="1"8. onchange="window.location=document.infosys.navigation.options[document.infosys.navigation.selectedIndex].value"
name="navigation">9. <OPTION selected>-------------------</OPTION>10. <OPTION value="index.php?do=photos">photos </OPTION>11. <OPTION value="index.php?do=products">products</OPTION>12. </SELECT>13. <?php14. switch ($do) {15. case "photos":16. include “myfiles/photos.htm";17. $printer=“myfiles/printer.php?print_mode=1&&doc=photos.htm";18. break;19. case "products":20. include “myfiles/products.php";21. $printer=“myfiles/printer.php?print_mode=1&&doc=products.htm";22. break;23. } ?>24. </FORM>25. <P>Want to print? <a href="<?php echo "$printer" ?>">Printer Friendly Page</a> </P>26. </BODY>27. </HTML>
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myfiles/photos.htm
1. <html>2. <head>3. <title>Photo Gallery</title>4. </head>5. <body>6. <P> Please visit our photo gallery 7. <a href=“http://yahoo.com/photos">Here</a>8. </body>9. </html>
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Myfiles/products.htm1. <html>2. <head>3. <title>Product specification</title>4. </head>5. <body>6. <p>Motorola A6188 </P> Welcome to your new office. The new Motorola
Accompli A6188 is a Chinese/English WAP-enabled PDA and mobile phone. Which makes it the world's smartest way to..<P>
7. <img src=include/a6188.gif>8. <TABLE>9. <TR> <TD>Device Name </TD> <TD>Accompli A6188 </TD> </TR>10.<TR> <TD>GSM 900 </TD> <TD> Yes</TD> </TR>11.<TR> <TD>Input Method </TD> <TD>On-screen keyboard/Voice
Recognition </TD> </TR>12.</TABLE>13.</body>14.</html>
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myfiles/printer.php• <html>• <head>• <STYLE TYPE="text/css">• <?PHP• if ($print_mode != 1) { • include 'normal.css'; • } else { • include 'printer.css'; • } • ?>• </STYLE>• </head>• <body>• Print Friendly Page:• <?PHP• include "$doc";• ?>• </body>• </html>
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myfiles/normal.cssmyfiles/printer.css
normal.css
1. body { color: white; background-color: #003366; font-size: 12pt}
2. A{color:#6666FF; text-decoration:none}
3. A:visited{color:#6666FF; text-decoration:none}
4. A:active{color:#6666FF; text-decoration:none}
5. A:hover{color:#6666FF; text-decoration:underline}
printer.css
1. BODY {margin: 2em; color: black; font-size: 12pt; text-indent: 2em;
2. /* i.e. 36pt */}
3. IMG {display: none}
4. table {font-size: 12pt; background: none; width: 100%;}
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myfiles/a6188.gif
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Estate broker example
• broker.htmA simple form with 4 fields Name, Surname, FlatHave and FlatWant with a submit button that will call the process_form.php file.
• process_form.phpThe variables $Name, $Surname, $FlatHave and $FlatWant are added to the “list” table of “broker” database. A mail is sent to the manager about the new entry added.
• display.phpDisplay everything from “list” table.
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broker.htm1. <html>2. <head>3. <title> Add Record</title>4. </head>5. <body>6. Please add the record here...7. <FORM name="myform" ACTION="process_form.php" METHOD="POST">8. Your Name: <INPUT TYPE="TEXT" NAME="Name"><br>9. Your Surname: <INPUT TYPE="TEXT" NAME="Surname"><br>10.Flat Have at: <INPUT TYPE="TEXT" NAME="FlatHave"><br>11.Flat Want at: <INPUT TYPE="TEXT" NAME="FlatWant"><br>12.<INPUT TYPE="SUBMIT" VALUE="Add Record" NAME="sendit">13.<INPUT TYPE="SUBMIT" VALUE="Cancel" NAME="cancelit"><br>14.</FORM>15.</body>16.</html>
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process_form.php
• <html>• <body>• <?php• mysql_connect("","","");• mysql_select_db("broker");• mysql_query ("INSERT INTO list values (´´, ´$Name´,
´$Surname´, ´$FlatHave´, ´$FlatWant´);");• ?>• Thank you for your entry.• </body>• </html>
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• Now can you send an e-mail to the manager whenever someone adds an entry?
• Add the following code in the process_form.php file• <?php• mail("[email protected]", "Entry Added","• Name : $Name• Surname : $Surname• Flat Have : $FlatHave• Flat Want : $FlatWant• ");• ?>
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display.php1. <html>2. <body>3. The data stored into the “broker” Database -“List” Table.4. <?php5. mysql_connect("","","");6. mysql_select_db("broker");7. $query = "select * from list";8. $result = mysql_query ($query);9. while($row = mysql_fetch_array($result)) 10.{11.echo $row[Name] ."<br>". $row[Surname]."</p>";12.}13.?>14.</body>15.</html>
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contents of database student Part I
• <?php• • $dbname = "student";• $loginname = "shaileshr21";• $loginpass = "";• $dbhost = "mysql";• • echo('<html><body bgcolor="#FFFFFF">');• echo('<font face="arial" size="+4"><center>');• echo(" $dbname");• • $id_link = @mysql_connect($dbhost, $loginname, $loginpass);• • $tables = mysql_list_tables($dbname, $id_link);• • $num_tables = mysql_num_rows($tables);
• // store table names in an array• $arr_tablenames[] = '';•
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contents of database student Part II
• // store number of fields per table(index 0,1,2..) in an array• $arr_num_fields[] = '';• for ($i=0; $i < $num_tables; $i++) {• $arr_tablenames[$i] = mysql_tablename($tables, $i);• $arr_num_fields[$i] = mysql_num_fields(mysql_db_query($dbname, "select *
from $arr_tablenames[$i]", $id_link));• }• • // store field names in a multidimensional array:• // [i] == table number, [ii] == field number for that table• for ($i=0; $i < $num_tables; $i++) {• for ($ii=0; $ii < $arr_num_fields[$i]; $ii++) {• $result = mysql_db_query($dbname, "select * from $arr_tablenames[$i]",
$id_link);• $hash_field_names[$i][$ii] = mysql_field_name($result, $ii);• } • }
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contents of database student Part III• for ($i=0; $i < $num_tables; $i++) {• echo("<center><h2> $arr_tablenames[$i] </h2></center>");• echo('<table align="center" border="1"><tr>');• $result = mysql_db_query($dbname, "select * from $arr_tablenames[$i]", $id_link);• for ($ii=0; $ii < $arr_num_fields[$i]; $ii++) {• echo("<th>");• echo $hash_field_names[$i][$ii];• echo("</th>");• }• echo("</tr><tr>");• $number_of_rows = @mysql_num_rows($result);• for ($iii = 0; $iii < $number_of_rows; $iii++) {• $record = @mysql_fetch_row($result);• for ($ii=0; $ii < $arr_num_fields[$i]; $ii++) {• echo("<td>");• // echo $record[$ii];• $mytext = nl2br($record[$ii]);• echo $mytext;• echo("</td>");• }• echo("</tr>");• }• echo("</table>");• }• echo('</body></html>');• ?>
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Display Bookmarks Part I• <html>• <head>• <basefont face="Arial">• </head>• <body>
• <?php• // set database server access variables:• $host = "mysql";• $user = "shaileshr21";• $pass = "";• $db = "student";
• // open connection• $connection = mysql_connect($host, $user, $pass) or die ("Unable to connect!");
• // select database• mysql_select_db($db) or die ("Unable to select database!");
• // create query• $query = "select concat('<a href=\"',Website,'\">', Website, '</a>'), Explanation from Bookmarks where
Catgegory='$mycat'";
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Display Bookmarks Part II• echo "<h2>$mycat</h2>";• // execute query• $result = mysql_query($query) or die ("Error in query: $query. ".mysql_error());• // see if any rows were returned• if (mysql_num_rows($result) > 0) {• // yes• // print them one after another• echo "<table cellpadding=10 border=1>";• while($row = mysql_fetch_row($result)) {• echo "<tr>";• echo "<td>".$row[0]."</td>";• echo "<td>" . $row[1]."</td>";• echo "</tr>";• }• echo "</table>";• }• else {• // print status message• echo "No rows found!";• }
• // free result set memory• mysql_free_result($result);
• mysql_close($connection);• ?>• </body>• </html>
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Mysql front-ends
• phpMyAdminSearch across tables, Most Popular, (free software)
• phpFlashMyAdminUser friendly flash interface, graphical representation of innodb tables, (Paid)
• MySql Data ManagerBetter Administrative interface in perl (Paid)
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Mysql interface
• CSV to MySQLhttp://www.sqldbu.com/eng/sections/tips/normalize.htmlUpload the .csv and get the create table and insert statements
• MySQL to CSVhttp://saraswaticlasses.com/sites/dump.phpType the table name and password to download the records in the excel form.
• MySQL to RSShttp://saraswaticlasses.com/sites/createrss.htmPublish the records from your mysql database using the RSS feed without any web interface.
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Simple RSS Reader• <?php
• $cookies = array();• getcookies();
• if ($_GET["deleteall"]=="yes") {• foreach($cookies as $id=>$url) {• deletecookie($id);• }• header("Location: $PHP_SELF");• } elseif(is_numeric($_GET["delete"])) {• deletecookie($id);• header("Location: $PHP_SELF");• } elseif(!empty($_GET["formfeedurl"])) {• addcookie($formfeedurl);• header("Location: $PHP_SELF");• } elseif ($cookiecount > 0) {• foreach($cookies as $id=>$url) {• echo "<!-- FeedCookie[$id] == $url -->"; // For debugging, or something.• ?>• <script language="javascript" src="http://p3k.org/rss/index.r?url=<?php echo $url; ?>%3Ff
%3D7&align=left&width=300&frameColor=black&titleBarColor=%23add8e6&titleBarTextColor=black&boxFillColor=white&textColor=black&fontFace=&maxItems=7&compact=&showXmlButton=&javascript=true""></script>
• <?php• }• } else {• // There are no feeds defined.• }• ?>
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Simple RSS Reader II
• <p style="clear: both">• <form action="<?php echo $PHP_SELF; ?>">• <input type="text" name="formfeedurl" size="26">• <input type="submit" name="Add" value="Add Feed">• </form>• <a href="<?php echo $PHP_SELF; ?>?
deleteall=yes">Delete All Cookies</a><p>• <a href="<?php echo $PHP_SELF; ?>?
source=yes">Source Code</a><p>
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Simple RSS Reader Part III• <?php
• function getcookies() {• global $cookiecount, $cookies;• foreach ($_COOKIE as $name=>$value) {• if (ereg("^FeedCookie-([0-9]{1,2})$",$name,$regs)) {• $id = (int)$regs[1];• $cookies[$id] = $value;• }• }• $cookiecount = count($cookies);• }
• function addcookie($value) {• global $cookies;• for ($i=0; $i<100; $i++) {• if (!isset($cookies[$i])) {• $id = $i;• break;• }• }• if (!isset($id)) {• echo "No ID.";• return 0;• }• • setcookie("FeedCookie-$id",$value,time()+31536000);• return 1;• }
• function deletecookie($id) {• global $cookies;• if (isset($cookies[$id])) {• setcookie("FeedCookie-$id","",time()-3600);• return 1;• } else {• return 0;• }• }
• if ($source==yes) { • $source = 'simplefeed.php';• highlight_file( $source ); • }
• ?>