3. Start with an example_PHP tutorial

3 PHP Practice


Many features of PHP are related to other software or tools. Using the PHP knowledge we have learned so far, we can try to build a simple interactive website. We can learn a lot through this process. Okay, let's now focus on the construction of a typical personal website.



3.1 Plan a site

Generally, a personal site includes a welcome page, a guestbook page, a bookmark link page, a counter, contact information, and even Photo collection and some music files and so on. Let’s start with a title page, a contact information page, and a resume page. We also need standard, universal page headers and footers.



Title page --front.html





Here we have a very simple html file:

My Personal Homepage

Contact Information

---

You can contact me at 1-800-PHP-INFO

---

Copyright ? Myself, 1999

3.2 HTML to PHP



As you can see from above, every page has the same header and footer. Writing the same information to each page like above is fine when the workload is light, but imagine how much effort you have to expend when there are more than 100 pages and you need to change their header or bottom for them all? What a tedious and boring task it is to manually change page after page! So we should write PHP header and bottom files for these pages, and then we just need to reference them in every HTML page. We will place these include files in a subdirectory called include. Below we will write the common content of these sites into the file.



Site-wide common variable settings: common.inc


// Site-wide common variables

$ MyEmail = "phptalk@tnc.org";

$MyEmailLink = "$MyEmail";

$MyName = "PHP Talk";

$MySiteName = $MyName."'s Home Page";

?>



General page header: header.inc


// Define the general page header

?>

---

Bottom of the general page: footer.inc


// Bottom of the general page

?>

---

Copyright ? by



, 1999

New page front.php3:


include("include/common.inc");

$title = "Welcome";

include("include/ header.inc");

?>

Welcome to my humble abode, although there is nothing here yet.

But I hope there will be more soon.

include("include/footer.inc");

?>



New cont.php3:


include("include/common.inc");

$title = " Contact Information";

include("include/header.inc");

?>

You can pass 1 -800-PHP-INFO Contact me

include("include/footer.inc");

?>



Now you can guess the benefits of this arrangement. If you want to change the header or bottom of the page, you only need to change the corresponding file. If you want to change your e-mail address or even your name, just modify the common.inc file. It's also worth noting that you can include files with any file name or file extension into your file, and you can even include files from other sites.



3.3 Counter



Let’s add a counter to the homepage. This example has been told many times, but it is still useful to demonstrate how to read and write files and create your own functions. counter.inc contains the following code:


/*


A simple counter

*/

function get_hitcount($counter_file)

{

/* Return the counter to zero

In this way, if the counter has not been used, the initial value will be 1

Of course you can also set the initial value to 20000 to deceive people

*/

$count=0;

// If the file storing the counter already exists, read Get the content

if ( file_exists($counter_file) )

{

$fp=fopen($counter_file,"r");

// We only took the top 20, I hope your site will not be too popular

$count=0+fgets($fp,20);

// Due to the function fgets( ) returns a string, which we can automatically convert to an integer by adding 0

fclose($fp);

// The file operation is completed

}

//Increase the count value once

$count++;

//Write the new count value to the file

$fp=fopen($counter_file, "w");

fputs($fp,$count);

fclose($fp);

# Return count value

return ( $count);

}

?>

Then we change the front.php3 file to display this counter:


include("include/counter.inc");

// I put the counter value in the file counter.txt, read it out and output it

printf ("%06d

n",

get_hitcount("counter.txt"));

include( "include/footer.inc");

?>

Check out our new front.php3



3.4 Feedback Form



Let’s add another feedback form for your viewers to fill out and e-mail to you. For example, we use a very simple method to implement it. We only need two pages: one to provide the viewer with an input form; the other to obtain the form data, process it, and mail it to you.



Getting form data in PHP is very simple.When a form is sent, each element contained in the form is assigned a corresponding value, and can be used like a reference to a general variable.

In process_form.php3, the variable $mytext is assigned the entered value - very simple! Similarly, you can get variable values ​​from form elements such as list boxes, multi-select boxes, radio boxes, buttons, etc. The only thing you have to do is give each element in the form a name so that you can reference it later.



According to this method, we can generate a simple form containing three elements: name, e-mail address and message. When the visitor sends the form, the PHP page (sendfdbk.php3) that processes the form reads the data, checks whether the name is empty, and finally emails the data to you.



Form: form.php3


include("include/common.inc");

$ title = "Feedback";

include("include/header.inc");

?>

< FORM ACTION="sendfdbk.php3" METHOD="POST">

SIZE="20" MAXLENGTH= "30">

value="Your Email" NAME="email">




<br><br>Your feedback on my home page.<br><br>

include("include/footer.inc");

?>



Process form: sendfdbk.php3


include("include/common.inc");

$title = "Feedback ";

include("include/header.inc");

if ( $name == "" )

{

// Now I hate anonymous comments!

echo "Duh ? How come you are anonymous?";

}

elseif ($name == "Your name")

{

// This viewer really doesn’t want to be named!

echo "Hello ? Your name is proposed to be replaced with

your actual name!";

}

else

{

// Output a polite thank you

echo "

Hello, $name.




Thank you for your feedback. BR>

$MyName


$MyEmailLink

";

// Finally mail out

mail($ MyEmail, "Feedback.","

Name : $name

E-mail : $email

Comment : $comment

");

}

include("include/footer.inc");

?>



3.5 Simple on-site search engine



PHP can call external programs. In a Unix environment we can use the program grep to implement a simple search engine. We can make it a little more complicated: use a page to output a form for users to enter search strings and output query results.


include("include/common.inc");

$title = "Search";

include("include/ header.inc");

?>

" METHOD="POST">

"

SIZE="20" MAXLENGTH="30">

if ( ! empty($searchstr) )

{

// empty() is used To check whether the query string is empty

// If it is not empty, call grep query

echo "

---

n";

// Call grep to check Query all files in case-insensitive mode

$cmdstr = "grep -i $searchstr *";

$fp = popen( $cmdstr, "r" ); // Execute Command and output pipeline

$myresult = array(); // Store query results

while( $buffer = fgetss ($fp, 4096))

{

// grep returns this format: File name: the number of lines in the matching string

// Therefore we use the function split() to separate and process the data

list($fname, $ fline) = split(":",$buffer, 2);

// We only output the result of the first match

if ( !defined($myresult[$fname]) )

$myresult[$fname] = $fline;

}

// Now we store the results in the array, we can process and output them below

if ( count($myresult) )

{

echo "

n";

while(list($fname,$fline) = each($myresult))

echo "
1. 
   
   $fname : $fline
n";

echo "

n";

}

else

{

// If not Query results

echo "Sorry. Search on $searchstr

returned no results.
n";

}

pclose($fp);

}

?>


include("include/footer.inc" ; . Contains the current file name.

fgets() reads the file line by line, with a maximum length of 4096 (specified) characters.

fgetss() is similar to fgets(), except that it parses the output HTML tags.

split() has a parameter of 2, because we only need to split the output into two parts. Also need to omit ":".

each() is an array operation function, used to traverse the entire array more conveniently.

The functions of popen() and pclose() are very similar to fopen() and fclose(), except that pipeline processing is added.

Please note that the above code is not a good way to implement a search engine. This is just an example to help us learn PHP better. Ideally you should build a database of keywords and then search them.




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3PHP Practice Many features of PHP are related to other software or tools. Using the PHP knowledge we have learned so far, we can try to build a simple interactive website. Take advantage of this...