ZEND PHP 5 Certification STUDY GUIDE

Streams and Network Programming ” 243
Simple File Functions
In addition to the “traditional” C-like file-access functions, PHP provides a set of
simplified functions that, effectively, allow you to perform multiple file-related operations
with a single function call.
As an example, readfile() will read a file and write it immediately to the script’s
standard output; this is useful when you need to include static files, as it offers much
better performance and resource utilization than C-style functions:
i
header("content-type: video/mpeg");
readfile("my_home_movie.mpeg");
Similarly, file() will let you read a file into an array of lines (that is one array element
for each line of text in the file). Prior to PHP 4.3.0, it was common to use this function
together with implode() as a quick-and-dirty way to load an entire file into memory.
More recent versions of PHP provide the file_get_contents() function specifically
for this purpose:
// Old Way
$file = implode("\r\n", file("myfile.txt"));
// New Way
$file = file_get_contents("myfile.txt");
Loading an entire file in memory is not always a good idea—large files require a significant
amount of system resources and will very rapidly starve your server under load.
You can, however, limit the amount of data read by file_get_contents() by specifying
an appropriate set of parameters to the function.
Licensed to 482634 - Amber Barrow (itsadmin@deakin.edu.au)
As of PHP 5.0.0, file_put_contents() was added to the language core to simplify
the writing of data to files. Like file_get_contents(), file_put_contents() allows
you to write the contents of a PHP string to a file in one pass:
$data = "My Data";
file_put_contents("myfile.txt", $data, FILE_APPEND);