As web developers, we know the importance of the JavaScript console provided by the browser in testing out code snippets. We don't need to write an entire HTML page and JavaScript code just to verify the functioning or logic of a small routine we wrote. Instead, we simply run the expressions in the console and immediately see the results. Similarly, a REPL (Read-Eval-Print Loop) is the console of a programming language in which we can write code line-by-line and see what it does. [...] PHP's REPL is very good in what it does, although it does have some limitations. [...] And so, Boris tries to solve these problems and other concerns as well.

He walks you through the installation (via a git clone and, later, through Composer) and shows how to run it as well as some sample output. He also shows how to make a custom command-line Boris runner and how to embed it into your application. His example of a tool that would benefit from this is a command-line web service client using Boris and Guzzle.

Whenever you're working on a project, are you consistent? Are you consistent in your coding style, consistent in your documenting, consistent in your database naming conventions? Better yet, do you and your team have a coding standard which you consistently adhere to? If you don't, you're buying yourself and others a world of pain - which is painlessly simple to avoid. Today I'm banging the drum, shouting from the street corner, calling from the cathedral spire, imploring you to do one thing, above all else - pick a coding standard and then BE CONSISTENT!

His five reasons for implementing (and effectively using) a coding standard are:

• Poor, Inconsistent Code - Causes You Pain
• Your Code is Easier to Read
• Your Code is Easier to Understand
• Your Code is Easier to Maintain
• Your Code is Easier to Collaborate on

Check out the post for summaries of each point.

Read Preferences are a new Replica Set and Sharding feature implemented by most MongoDB drivers that are supported by 10gen. This functionality requires MongoDB 2.2. In short, Read Preferences allow you to configure from which nodes you prefer the driver reads data from. In a Replica Set environment it is the driver that does the selection of the preferred node, and in a Sharded environment it is the mongos process that routes queries according to the defined Read Preferences.

He starts with a look at the read preference types (like "primary", "secondary" and "nearest") how the connection manager works to handle each type. He includes some code samples showing how to configure your MongoClient connections to use these various types of preferences. He also introduces the concept of "tags" for the replica set - aliases to make them a bit easier to identify when making a connection and how to define them in the connection string.

The goal is to figure out some way of measuring what features in programming systems help programmers understand wht they are doing, and how this can be used to make systems that lead to higher quality software. Mike is currently running an experiment where he shows people several short Python programs and asks them to tell the output of the program. The test subject is sitting in front of an eye tracker, so afterwards Mike can see where you were looking at various times during the experiment.

The results are pretty interesting and Eric likens it to a sort of "just-in-time compilation" that the mind is doing as it reads through the code, not a straight forward read through. The timing of the read is interesting too, noting that once something is figured out, it's run through faster the following times.

One aspect he's interested in is how the approach of inexperienced programmers differs from that of experienced programmers. For example, there seems to be some evidence that following variable naming conventions helps experienced programmers understand the code much quicker, while breaking these conventions leads to a severe penalty. On the other hand, inexperienced programmers seem to take about as long regardless of how the variables are named.

This study is still going on and, if you're in the Bloomington, Indiana area and would like to lend your eyes to the cause, send an email over to Mike Hansen (more on the subject on his blog here).

This is a PHP tutorial for the PostgreSQL database. It covers the basics of PostgreSQL programming with PHP. The examples were created and tested on Linux. [...] PostgreSQL is a powerful, open source object-relational database system. It is a multi-user, multi-threaded database management system. It runs on multiple platforms including Linux, FreeBSD, Solaris, Microsoft Windows and Mac OS X. PostgreSQL is developed by the PostgreSQL Global Development Group.

The chapters guide you through every step you'll need:

• An introduction to PostgreSQL and getting it and PHP support installed (with the php5-pgsql package)
• Example code showing how to extract data from your tables
• Working with images and storing their data in a table
• Pulling out the metadata from the database, things like number of rows returned and table information
• Transactions and database-side processing

Recently on a project I had to make changes to a underlying portion of the sites architecture to move sessions in Zend Framework from file storage to database storage. However this affected a piece of the architecture. Node.js, which manages all our real time interaction, looked at sessions at the file level. This was quite a easy transition for the function as it was abstracted away in a function call so the theory was to just replace the function "guts" with a new component.

The post shows the code he came from (which pulled in the PHP session file and extracted the session data manually) over to a new database-based version that selects from the SESSIONS table and pulls out the data. It's based on the table having an "id" column and the Zend_Auth namespace it uses.

In this fifth part of an eight-part series on working with file and operating systems with PHP, you'll learn how to read data from a file and move the file pointer.

Example code is included showing how to use the file, file_get_contents, fgetc, fgetcsv, readfile and fscanf (among several others). Also included is code showing how to use the fseek method to move around in a file.

Normally our code is coded once and executed thousands of times, and we must keep in mind that CPU time many times means money. We need to balance it (as always). But, WTH. I like micro-optimizations, and here comes another one: Checking the access to arrays with PHP.

He sets up three different options and tests the memory consumption and run time for each:

• Referencing a value from a large array outside a for loop
• Referencing a value from a large array inside a for loop
• Echoing out the value from a large array inside a for loop

Not surprisingly, all three approaches yield just about the same results. It probably has more to do with the size of the large array than how it's accessed. The fetch outside the for loop did come in slightly under the others, but not enough to worry about it.

The following [example] is a very short code to read the version number of a PDF document using PHP. I needed this recently during a PDF processing app developed in PHP. As Adobe uses different compression methods in various versions, it becomes necessary to be able to identify the version of the PDF under work.

The code opens the file with a fopen and parses a certain line for the major and minor version. The PDF extension for PHP can do something similar with the pdf_get_value function passing in either "major" or "minor" as the second parameter.

GSM modems are similar than normal modems. They've got a SIM card and we can do the same things we can do with a mobile phone, but using AT and AT+ commands programmatically. That's means we can send (and read) SMSs and create scripts to perform those operations. [...] The idea is the following one: We are going to create a main class called Sms. It takes in the constructor (via dependency injection) the HTTP wrapper or the serial one (both with the same interface).

His base SMS class provides open, close and read methods that talk with the device set in a child class (in this case "/dev/ttySO"). The sendSMS method is defined to take in the number to send to and the message. The AT command examples show how to send the SMS message, read all of the messages waiting and delete an SMS from the device. You can get the full code from github.