Home arrow PHP arrow PHP 101 (part 5) - The Wonderland Factor

PHP 101 (part 5) - The Wonderland Factor

This concluding article in the series illustrates PHP's filefunctions, with examples of how to read and write files on the system. Italso includes an explanation of user-defined functions, return values andfunction arguments, together with some not-so-real-life examples.

TABLE OF CONTENTS:
  1. PHP 101 (part 5) - The Wonderland Factor
  2. So Who Are You, Anyway?
  3. Graffiti For The Masses
  4. Calling Godzilla
  5. Q
  6. Arguments And Responses
  7. The Wonderland Factor
By: Vikram Vaswani and Harish Kamath, (c) Melonfire
Rating: starstarstarstarstar / 7
September 06, 2000

print this article
SEARCH DEV SHED

TOOLS YOU CAN USE

advertisement
If you've been following along, you already know how PHP can be used to extract data from a database...it's as easy as apple pie. But in the real world, data isn't always stored in neat rows and columns, and you're quite likely to come across situations where the data you need is actually stored in a bunch of ASCII text files.

You have three options here. You could con someone into the mind-numbing task of inserting the textual data into a database. You could throw up your hands in despair and look for another job. Or you could use PHP's built-in file functions to extract and format the data.

The first option requires guile and cunning. The second is unacceptable. And the third requires this issue of PHP 101.

Over the next few pages, we'll be discussing the basics of PHP's file functions, together with some interesting examples. And then we'll explore the murky tunnels of user-defined functions, and delve deep into the mysteries of local and global variables, return values and function parameters. Pack some warm clothes, bring enough food and get someone to feed the dogs - this is one journey you don't want to miss!{mospagebreak title=Windy Nights} From the days of C, programmers have had the ability to create files on the system, read them and perhaps even execute them via the shell. And, like all good programming languages, PHP comes with a bunch of functions which allow you to read and write files with minimum effort.

Let's get straight into the nitty-gritty of reading a file. Create a text file and populate it with some text - here's what our file, which we've named "random.txt", looks like:

It was a dark and stormy evening. Outside the pub, the wind wailed and moaned, singing dirges to long-lost sailors and making the timbers creak. Inside, all was silent except for a brave nightlight that kept the ghosts awake.

Oh, what I wouldn't give for a slug of ale just about now!
Before you can use PHP to read the contents of this file, you need to ensure that you have permission to read it. On *NIX, this is accomplished via the "chmod" command.- try

$ chmod 744 random.txt
to make it world-readable.

And here's some simple PHP code that reads the file and returns the contents and file size:

<?php // read file $bytes = readfile("random.txt"); // display size echo "<br>File is $bytes bytes in size."; ?>
And here's the output:

It was a dark and stormy night. Outside the pub, the wind wailed and moaned, singing dirges to long-lost sailors and making the timbers creak. Inside, all was silent except for a brave nightlight that kept the ghosts awake. Oh, what I wouldn't give for a slug of ale just about now! File is 286 bytes in size.
As you can see, readfile() doesn't do much - it simply reads the file and displays the contents. It also returns the size of the file in bytes - we've displayed this using an echo() above.

A far more useful function, and one which lets you format the extracted data, is the file() function, which allows you to read the file into a regular PHP array. Each element of the array represents one line of the file, and therefore, the size of the array is representative of the number of lines in the file. Take a look:

<?php // set filename $filename = "random.txt"; // read file into array $contents = file($filename); // get array length $length = sizeof($contents); echo "<b>File $filename contains $length line(s)</b><p>"; // display each line with "for" loop for($counter=0; $counter<$length; $counter++) { echo "$contents[$counter]<br>"; } ?>
In this case, we've used the file() function to read the contents of the entire file into an array called $contents. Using the sizeof() function, we can obtain the length of the array, which is the same as the number of lines present in the text file. The "for" loop is used to read and display each element of the array.

And here's the output:

File random.txt contains 3 line(s) It was a dark and stormy night. Outside the pub, the wind wailed and moaned, singing dirges to long-lost sailors and making the timbers creak. Inside, all was silent except for a brave nightlight that kept the ghosts awake. Oh, what I wouldn't give for a slug of ale just about now!


 
 
>>> More PHP Articles          >>> More By Vikram Vaswani and Harish Kamath, (c) Melonfire
 

blog comments powered by Disqus
escort Bursa Bursa escort Antalya eskort
   

PHP ARTICLES

- Hackers Compromise PHP Sites to Launch Attac...
- Red Hat, Zend Form OpenShift PaaS Alliance
- PHP IDE News
- BCD, Zend Extend PHP Partnership
- PHP FAQ Highlight
- PHP Creator Didn't Set Out to Create a Langu...
- PHP Trends Revealed in Zend Study
- PHP: Best Methods for Running Scheduled Jobs
- PHP Array Functions: array_change_key_case
- PHP array_combine Function
- PHP array_chunk Function
- PHP Closures as View Helpers: Lazy-Loading F...
- Using PHP Closures as View Helpers
- PHP File and Operating System Program Execut...
- PHP: Effects of Wrapping Code in Class Const...

Developer Shed Affiliates

 


Dev Shed Tutorial Topics: