Working with binary files in PHP is rarely a requirement. However when needed the PHP ‘pack’ and ‘unpack’ functions can help you tremendously. To set the stage we will start with a programming problem, this will keep the discussion anchored to a relevant context. The problem is this : We want to write a function that takes a image file as an argument and tells us whether the file is a GIF image; irrelevant with whatever the extension the file may have. We are not to use any GD library functions.
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functions
Easy way to build GET query strings in php
Passing variables with a url is such a frequent thing programmers do that most of you may think this post is unwarranted. We call this method of passing variables as GET, the other being POST. It is one of those things which can be easily done in php. Lets take an example. You are to query a database and for that you need to send three variables via GET – city, id, paid.
The common way to pass them via GET is to construct a query string as below:
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Simple Pagination in PHP tutorial
Pagination is a frequent requirement in web development projects. Most PHP developers must have already implementated paging in one form or other in their projects. In this post we will see how to add pagination the easy way using PEAR’s Pager class. Note that in all the posts I use PHP 5.x.x, so if you are still stuck at version 4.x.x, its already time to upgrade.
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WHOIS directory lookup in PHP
Net_Whois lets you query a internet name directory service in a easy to use manner. WHOIS is a protocol which is widely used to determine the owner of a domain name, an IP address by querying an official name database. One possible application I can think of is to see if DNS servers are set correctly for various domains I handle regularly.
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Ping a server using PHP
PEAR’s Net_Ping is a niffty wrapper class for executing ping calls from PHP. You can use it to check if a remote server is responding correctly. The library can be download from here.
Installation
Net_Ping being a Pear package we will use the Pear installer to download and install it. I recommend to always use the Pear installer to download packages rather than downloading it manually as the Pear installer automatically downloads any dependent packages.
pear install Net_Ping-2.4.4 |
Usage
A example of using Net_Ping is given below.
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Reading raw POST data in PHP
A quick tip for reading raw http POST data in PHP. For example if we have a xml posted to a page, we can read the raw data with the following code.
$xml = file_get_contents('php://input'); |
We could use $HTTP_RAW_POST_DATA instead, but many times it does not work due to some php.ini settings. Note that ‘php://input’ does not work with enctype=”multipart/form-data”.