Introduction to PHP (Hypertxet PreProcessor, HyperText Processor)

Part 3

PHP Arrays and Superglobals

References

· Chapter 8 Introduction to Server-Side Development with PHP of the Text Book Entitled Fundamentals of Web Development, by Randy Connolly and Ricardo Hoar

· PHP 5.6.14 Released Oct. 1, 2015

· PHP 5.6.1 Released Oct. 2, 2014, http://php.net/

· PPH Documentation, http://php.net/urlhowto.php

· PHP Language Reference, http://php.net/manual/en/langref.php

Predefined Superglobals, http://php.net/manual/en/language.variables.superglobals.php

Superglobals // Built-in variables that are always available in all scopes

· $GLOBALS // All variables available in global scope (array containing info about the

request and the server)

· $_SERVER // Server and execution environment info

· $_GET // HTTP GET variables (array of query string data passed to the server via

the URL)

· $_POST // HTTP POST variables (array of query string data passed to the server

via the HTTP header)

· $_FILES // HTTP file upload variables (array of file items uploaded to the server)

· $_REQUEST // HTTP request variables (array containing the contents of $_GET,

$_POST, and $_COOKIE)

· $_SESSION // Session variables (array contains session data)

· $_ENV // Environment variables (array) of a server

· $_COOKIEs // Array of Cookie data passed to page via HTTP request

HTTP Cookies, http://php.net/manual/en/features.cookies.php

· PHP Supports for HTTP Cookies

· Set the session cookie parameters, http://php.net/manual/en/function.session-set-cookie-params.php

$_SERVER, http://php.net/manual/en/reserved.variables.server.php

· An array containing information such as Headers, Paths, Script Location

· There is no guarantee that every web server will provide any of these ino

· See CGI/1.1 Specification, http://www.faqs.org/rfcs/rfc3875.html

Example 1. A PHP Page that uses print Server retained info in the $_SERVER

Also use date(), http://php.net/manual/en/function.date.php

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

<head>

<title>This HTML page prints out your b</title>

</head>

<body>

This HTML page prints out your browser info and the IP addresses of the HTTP

Request.

Your Computer Name: <?php echo $_SERVER['HTTP_HOST'] ?>

Your Browser is : <?php echo $_SERVER['HTTP_USER_AGENT'] ?>

Your IP address : <?php echo $_SERVER['REMOTE_ADDR'] ?>

Your IP address : <?php echo $_SERVER['REMOTE_PORT'] ?>

Server Name: : <?php echo $_SERVER['SERVER_NAME'] ?>

Server Protocol : <?php echo $_SERVER['SERVER_PROTOCOL'] ?>

Server Software : <?php echo $_SERVER['SERVER_SOFTWARE'] ?>

Request Method : <?php echo $_SERVER['REQUEST_METHOD'] ?>

Request Time : <?php echo $_SERVER['REQUEST_TIME'] ?>

Request Date: <?php echo date("D:d:M:Y:H:i:s") ?>;</body>

</html>

Example 2: A PHP page that shows the contents kept in $_COOKIE from the server that process your form data.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<head>

<title>Displaying the Cookie Contents</title>

</head>

<body>

This PHP page prints out your Cookie Contents.

<?php

setcookie("color", "red");

echo $_COOKIE["color"];

</body>

</html>

Example 3. A PHP Page that shows Server and browser info in the $_SERVER.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<head>

<title>This HTML page prints out your b</title>

</head>

<body>

This HTML page prints out your browser info and the IP addresses of the HTTP

Request.

<?php

echo "Your Computer Name: " . $_SERVER['HTTP_HOST'];

echo " HTTP User Agent: " . $_SERVER['HTTP_USER_AGENT'];

echo " Your Browser is: " . $_SERVER['HTTP_USER_AGENT'];

echo " Your IP address: " . $_SERVER['REMOTE_ADDR'];

echo " Your Port address: " . $_SERVER['REMOTE_PORT'];

echo " Request Method: " . $_SERVER['REQUEST_METHOD'];

echo " Request Time: " . $_SERVER['REQUEST_TIME'];

echo " Server Name: " . $_SERVER['SERVER_NAME'];

echo " HTTP Host: " . $_SERVER['HTTP_HOST'];

echo " Server IP address " . $_SERVER['SERVER_ADDR'];

echo " Server Port " . $_SERVER['SERVER_PORT'];

echo " Server Protocol: " . $_SERVER['SERVER_PROTOCOL'];

echo " HTTP Connection: " . $_SERVER['HTTP_CONNECTION'];

echo " HTTP Accept Encoding" . $_SERVER['HTTP_ACCEPT_ENCODING'];

echo " Server Software: " . $_SERVER['SERVER_SOFTWARE'];

<?php echo " Request Date: " . date("D:d:M:Y:H:i:s"); ?>

</body>

</html>

Example 4. Handling the File Upload

· Using a HTML form for upload:

o POST method

· PHP File Upload

o Configure php.ini

§ file_uploads = on

§ upload_file_maxsize

§ post_max_size

§ memory_limit

§ max_execution_time

§ max_input_time

o POST method, http://php.net/manual/en/features.file-upload.post-method.php

o _$FILE array, keys

§ name – full file name

§ type – MIME (Multipurpose Internet Mail Extension) type of the file

· application, audio, image, message, multipart, text, video

§ tmp_name – full path to the location on your server

§ error

§ size

o Figure 9.12 Example (page 387), keys - http://php.net/manual/en/reserved.variables.files.php

§ echo $_FILE[“file1”][“name”]; // “sample1.png”

§ echo $_FILE[“file1”][“type”]; // “image/png”

§ echo $_FILE[“file1”][“tmp_name”]; // tmp/phpJ08pVh

§ echo $_FILE[“file1”][“error”]; // 0

§ echo $_FILE[“file1”][“size”]; //1219038

· References

o Handling File Uploads, http://php.net/manual/en/features.file-upload.php

o http://www.w3schools.com/php/php_file_upload.asp

o The Content-Type Header Field, http://www.w3.org/Protocols/rfc1341/4_Content-Type.html

o Media Types, 2015-10-12, http://www.iana.org/assignments/media-types/media-types.xhtml

<html>

<title> File Upload </title>

<body>

</form>

</body>

</html>

PHP Reading/Writing Files Support

o Stream Access

o Read just a small portion of the file at a time

o Most memory-efficient approach, but I/O intensive

o In-Memory File Access

o Read entire file into memory (PHP variable)

o Easier for file processing

Listing 9.19

<?php

$f = fopen("sample.txt", "r");

$ln = 0;

while ($line = fgets($f)) {

$ln++;

printf("%2d: ", $ln);

echo $line . " ";

}

fclose($f);

sample.txt

1: 01070,Picasso,The Actor,1904
2: 01080,Picasso,Family of Saltimbanques,1905
3: 02070,Matisse,The Red Madras Headdress,1907
4: 05010,David,The Oath of the Horatii,1784

Listing 9.20

PHP functions used

o array file(string $filename), read entire file into an array, http://php.net/manual/en/function.file.php

o array explode(string $delimiter, string $string), split a string by string, http://php.net/manual/en/function.explode.php

<?php

$filename="sample.txt";

// read the file into memory; if there is an error then stop processing

$paintings = file($filename) or die('ERROR: Cannot find file');

// our data is comma-delimited

$delimiter = ',';

// loop through each line of the file

foreach ($paintings as $painting) {

// returns an array of strings where each element in the array

// corresponds to each substring between the delimiters

$paintingFields = explode($delimiter, $painting);

$id= $paintingFields[0];

$artist = $paintingFields[1];

$title = $paintingFields[2];

$year = $paintingFields[3];

// do something with this data

//Not in book listing - but here for demo.

echo "Painting (#$id) $title by $artist in $year ";

}

PHP Functions Reference

· echo()

· unset() // Destroy variables

· func_get_args() // get function arguments

· func_num_args() // get function argument count

String Manipulation Functions

· strcmp() // string comparison, case sensitive

· strcasecmp() // string comparison, non case sensitive

· substr() // the sub string

· strlen() // The number of chars in the string

· strops() // The character position

· chop() // Remove all white spaces from its ends

· trim() // remove all white spaces from both ends

· strtolower() // covert to lower case characters

· strtoupper() // convert to upper case characters

Arithmetic Functions

· floor(), ceil(), round(), srand(), rand(), abs(), min(), max()

Ouput Functions

· print()

· printf() // formatted output

PHP Functions

· func_get_args() // http://us3.php.net/manual/en/function.func-get-args.php

· func_num_args()

<!DOCTYPE html>

<!—funct_arguments.php - A trivial example to illustrate a php document -->

<head>

<title> funct_arguments.php </title>

</head>

<body>

<?php

function func_dynamic() {

echo “ITC 250/CPET 499 Web Systems: “.func_num_args(). “Number of arguments. ”;

$args = func_get_args();

for($i = 0; $i < count($args); $i++{

echo “Passed arguments: {args[$i]} ;

}

func_dynamic(5, 4, 3, 2, 1 );

</body>

</html>