Simple PHP GuestBook

This is a simple guestbook script done in php, this is useful if you are developing simple projects, and likes to add a guestbook, however this needs tweaking for your needs. This script uses a flat file for database, like i said u'll need tweaking if you are gonna use mySQL database…Enjoy

// getenv() is used to determince the tmp dir
$tmpDir = getenv('TEMP');
if (!$tmpDir)
$tmpDir = "/tmp";
$dataFile = $tmpDir."/guestbook.dat";

class GuestBook {
// class variable definitions
var $gb_dat;
var $data;

GuestBook constructor
initializes guestbook data
function GuestBook($dataFile) {
$this->gb_dat = $dataFile;
$this->data = "";

// if data was posted, lets add an entry to the guestbook
if (!$this->addGuestBookEntry()) {
echo("Error in posting to the guestbook, please use <a href=\"".$_SERVER["PHP_SELF"]."\">".$_SERVER["PHP_SELF"]."</a> to post your entry.<br><br><hr>\n");
if ($this->data) $this->outputData();

reads the data from the guestbook data file
function _getData() {
$lines = @file($this->gb_dat);
if ($lines) {
$this->data = join($lines, "\n");

writes the contents of the guestbook data file to stdout
function outputData() {
echo $this->data;

use data from the post to create an HTML sniplet
function _createEntryHTML() {
// get the posted data
$name = $_POST["name"];
$email = $_POST["email"];
$company = $_POST["company"];
$message = $_POST["message"];

// this is a simple validation
if (!$name || !$message) {
echo ("You did not enter your name or message, please resubmit your entry.<br><br><hr>\n");
return NULL;

// get the current time
$today = date("F j, Y, g:i a");

// build the html for the posted entry
$data = "Posted: <b>$today</b> by <b>$name</b> <$email><br>".
"Company: $company<br>\n".

return $data;

write the data back to the datafile
function _writeDataFile() {
// open and clear the file of it's contents
$f = @fopen($this->gb_dat, "w");
if (!$f) {
echo ("Error opening $this->gb_dat.<br>\n");
return false;
// write the new file
if (fwrite($f, $this->data) < 0) {
echo ("Error writing data to $this->gb_dat.<br>\n");
return true;

this function formats the post data into html, and adds it
to the data file
function addGuestBookEntry() {
$entry = $this->_createEntryHTML();
if (!$entry) return false;
$this->data = $entry.$this->data;
return $this->_writeDataFile();

function outputForm() {
// below is the entry form for adding a guestbook entry
<a name="post"><b>Please sign our Guest Book</b></a><br>
<form action="<?php echo($_SERVER["PHP_SELF"]);?>" method="POST">
Name: <input type="Text" name="name" size="40" maxlength="50"><br>
Email: <input type="Text" name="email" size="35" maxlength="40"><br>
Company: <input type="Text" name="company" size="35" maxlength="40"><br>
<textarea name="message" cols="40" rows="8" wrap="PHYSICAL"></textarea><br>
<input type="Submit" name="action" value="Submit">
<input type="reset">

// create an instance of the guestbook,
// the guestbook constructor handles everything else.
$gb = new GuestBook($dataFile);

Now save this as a php file and run it on machine which has PHP5 or PHP4 installed….



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