Redirecting site or pages to a new domain or url aka 301 redirections

I learnt about 301 redirection when I moved my wordpress site from earlier domain to this new domain.

Htaccess redirect is better than the meta refresh or redirect tag because there is no delay as the browser reads the .htaccess file first. Here is how it works.

Go to your site’s root folder, download the .htaccess file to your local computer and edit it with a plain-text editor (ie. Notepad). If you are using FTP Client software and you don’t see any .htaccess file on your server, double check your setting and make sure you have turn on invisible / system files. Continue reading “Redirecting site or pages to a new domain or url aka 301 redirections”

Logging errors to file in PHP

PHP offers simple but effective solution to log all errors to a log fiie. On all production web server its a must that you turn off displaying error to end users via a web browser. Remember PHP gives out lots of information about path, database schema and all other sort of sensitive information. You are strongly advised to use error logging in place of error displaying on production web sites. The idea is quite simple -only developer should see php error log.

The way I choose to do it is by having a common config.php file containing this code and included in the first line of every page.

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// Display no errors in runtime pages
ini_set("display_errors" , "0"); 
 
// Log errors to file
ini_set("log_errors" , "1");
 
// Error log file path and name
ini_set("error_log" , "logs/Errors.log.txt");

Good luck!!!

Concatenate PDF in PHP

As requirement for one of my projects, I needed to concatenate multipe PDF files provided by the user into just one file.

To achieve this, we need the TCPDF and FPDI libraries.

Class to concatenate pdf, Pdf_concat.class.php:

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require_once('./includes/tcpdf/config/lang/eng.php');
require_once('./includes/tcpdf/tcpdf.php');
require_once('./includes/fpdi/fpdi.php');
 
class Pdf_concat extends FPDI {
     var $files = array();
 
     function setFiles($files) {
          $this->files = $files;
     }
 
     function concat() {
          foreach($this->files AS $file) {
               $pagecount = $this->setSourceFile($file);
               for ($i = 1; $i < = $pagecount; $i++) {
                    $tplidx = $this->ImportPage($i);
                    $s = $this->getTemplatesize($tplidx);
                    $this->AddPage('P', array($s['w'], $s['h']));
                    $this->useTemplate($tplidx);
               }
          }
     }
}

Usage: Continue reading “Concatenate PDF in PHP”

Php file_exists, does it really exists?

“Php functions are sometimes so confusing”, I don’t know how true that is, but I just found it to be true in this very case. Php’s file_exists, a function that seems like it is made to check if a file exists or not, is the one I encountered recently.

So I created this little test for this very purpose. I created an images folder with 2 files and 1 folder. Next I used file_exists function in 3 conditions with respective relative paths, to see which of those existed.

$file1="images/two.jpeg";
$file2="images/icon/one.jpg";
$file3="images/small/icon/";

if (file_exists($file1))
    echo "File one exists";

if (file_exists($file2))
    echo "File two exists";

if (file_exists($file3))
    echo "File three exists";

To my surprise all the conditions returned true.

File one exists
File two exists
File three exists

file_exists — Checks whether a file or directory exists.

According to php.net manual:

Irrespective of existence of file, file_exists function return true even if the path provided exists, which is in accordance with php manual’s definition, it’s just the name that is confusing. So, its better to use is_file() together with file_exists() if the objective is to check if the file really exists or is_dir()to check for directory.

Cheers!

Creating a zip file using php

Creating a zip file in php is as easy as creating them on your desktop using some zipping software. Php comes with inbuilt class that helps in making a zip file and provides all the functionality that you would ever need. Here is a simple function that I coded for my project. Hope it helps some peoples out there as well.

Php code:

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// creates a compressed zip file
function create_zip($files = array(), $filename=array(), $destination = '',$overwrite = false) {
	//if the zip file already exists and overwrite is false, return false
	if(file_exists($destination) && !$overwrite) { return false; }
 
	//vars
	$valid_files = array();
	$valid_names = array();
	$i=0;
 
	//if files were passed in...
	if(is_array($files)) {
		//cycle through each file
		foreach($files as $file) {
			//make sure the file exists
			if(is_file($file)) {
				$valid_files[] = $file;
				if(isset($filename[$i]) && $filename[$i]!='') {
					$valid_names[]=$filename[$i];
				} else {
					$valid_names[]=$file;
				}
			}
			$i++;
		}
	}
 
	//if we have good files...
	if(count($valid_files)) {
		//create the archive
		$zip = new ZipArchive();
		if($zip->open($destination,$overwrite ? ZIPARCHIVE::OVERWRITE : ZIPARCHIVE::CREATE) !== true) {
			return false;
		}
 
		$i=0;
		//add the files
		foreach($valid_files as $file) {
			$zip->addFile($file,$valid_names[$i]);
			$i++;
		}
 
		//debug
		//echo 'The zip archive contains ',$zip->numFiles,' files with a status of ',$zip->status;
 
		//close the zip -- done!
		$zip->close();
 
		//check to make sure the file exists
		return file_exists($destination);
	} else {
		return false;
	}
}

Continue reading “Creating a zip file using php”