Xdebug is a powerful debugging and profiling tool for php that allows you to find and fix errors faster by showing the entire stack trace and source code file and line number. If you want your php development to be error free you should use something like xdebug right from the beginning. A very useful… Read More »
Output Buffering Output buffering is processing mechanism where the output being generated by a program is held in a place till its size reaches a limit or the generation is complete. Only after, will the output be send to its destination. In php for example, doing and echo generates some output. Now this output might… Read More »
Php set_time_limit Php has a function called set_time_limit which can be used to dynamically adjust the maximum execution time permitted to a script. It allows specifying the time in seconds and limits the script execution time to that many seconds. The set_time_limit function whenever called, effectively extends the script execution time by that many seconds…. Read More »
SOAP and PHP SOAP is a protocol to exchange objects over http. It is used to implement apis and the data being exchanged is in xml format. Sometimes it might be required to modify the soap request to add custom http headers for example. Since SoapClient is a class, it can be extended and the… Read More »
When loading xml files in php through simplexml_load_string or domDocument class, sometimes an error like this might popup Warning: DOMDocument::loadXML(): Input is not proper UTF-8, indicate encoding ! OR Warning: simplexml_load_string(): Entity: line 93: parser error : Input is not proper UTF-8, indicate encoding ! The error occurs when the xml has some invalid characters… Read More »
The file_get_contents function is often used to quickly fetch a http url or resource. Usage is very simple and appears like this $content = file_get_contents('http://www.google.com/'); However the file_get_contents does not get the contents compressed. It requests the server to send everything in plain text format. Most websites are capable of serving compressed content, if they… Read More »
Socket Programming Socket programming involves connecting to remote machines on LAN or over the internet using ip addresses and port number. For example google.com has an ip “173.194.36.3” and runs http server on port 80. So a socket application can connect to that ip address on that particular port number and start data communication. Socket… Read More »
In your web application you might need to parse the user’s user-agent string to find out the browser/OS/device being used. This is necessary specially when your webapp tries to adapt to the user’s platform in a better way. For example a different layout for mobile device or restricted features/graceful degradation on a non supporting browser…. Read More »
The filter_var function of php is capable of validating many things like emails, urls, ip addresses etc. It does not have a direct option to validate a domain name however. So I coded up this little snippet that the filter_var function with a little tweak so that it can validate domain names as well. function… Read More »
Download a File using Curl Here is a quick curl snippet for php, that can download a remote file and save it. <?php set_time_limit(0); // File to save the contents to $fp = fopen ('files2.tar', 'w+'); $url = "http://localhost/files.tar"; // Here is the file we are downloading, replace spaces with %20 $ch = curl_init(str_replace(" ","%20",$url));… Read More »
Html to pdf If your php application needs to generate some kind of pdf report then the simplest approach would be to generate the report as an html and then convert it to pdf using some library. Plenty of libraries are available that can convert html to pdf in php. To name a few -… Read More »
Php applications might need to do some image processing if they are allowing users to upload pictures of somekind. This can include cropping, watermarking, compressing etc. To compress an image the quality needs to be adjusted. Here is a code example of how to do it: function compress_image($src, $dest , $quality) { $info = getimagesize($src);… Read More »
In a previous article we learned how to . Now lets do the reverse, that is extract tar.gz archives and get the files out. The code to extract a tar.gz archive is very simple and uses PharData class. Here is an example // decompress from gz $p = new PharData('files.tar.gz'); $p->decompress(); // creates files.tar //… Read More »
Tar is a common archive format used on linux. Alone it is just an archiving format, that is it can only pack multiple files together but not compress them. When combined with gzip or bzip2 files are compressed as well. Then it becomes a .tar.gz which is actually a gzip compressed tar file. Php has… Read More »
Proxy with Curl Curl is a very useful library for transferring data over various protocols like http, ftp, https etc. In other words curl can be used to programatically download a web page, or upload file to ftp etc. It also supports using a proxy. This means that curl requests can go through a proxy… Read More »
When working with data import and export for example, file formats like csv and excel are commonly used. Data can be exported to csv format and imported elsewhere. Also data might be entered manually in an excel file and then imported in the database. So there might be a need to convert excel files to… Read More »
Tcpdf is a pdf creation library for php that is written in pure php and works without the need of any external library. It also has the feature to generate 2d barcodes like qrcode and pdf417. The 2d barcodes can store much more information than the 2d ones like code39 and ISBN. It is recommended… Read More »
Consider a long running php script that does many tasks and after each task it outputs the status. echo 'Task 1 complete'; …. some delay … echo 'Task 2 complete'; …. more delay and more tasks … Now for such scripts it may be important to load the contents in browser as quickly as they… Read More »
Server sent events When running a long serverside task inside a web application it becomes very useful, if not necessary to report the progress of that task in realtime to the clientside, that is the browser. Earlier there was no easy way to do this and hacks had to be constructed to achieve such a… Read More »
If your php application is processing media files like mp3, then it might need to find details of the mp3 file like its playtime, bitrate, encoder etc. There is a very useful php library called Getid3 that can extract information from mp3 files. Its written in pure php and does not have any dependencies. Needs… Read More »