Chapter 9. File Access
Reading and writing files is common in PHP applications. Configuration and template files provide a way to customize a web application, and in order for these files to have their intended effect, a PHP application needs to read and write these files.
Reading and Writing Files
API function is one of the easiest and most common ways to read a file. It
was added in PHP 4.3.0 and was immediately popular so only
very old PHP 4 code does not use it. The following PHP code reads the file
named data.txt from the same folder that the PHP file
is in. The file is read as a long string that is assigned to the
If a file named data.txt does not exist, a
false boolean value is assigned to the
$contents variable. So, if the
data.txt file exists and is readable, a string is
returned, but if the data.txt file does not exist or
is not readable, a boolean is returned.
As discussed previously, PHP API functions, including
file_get_contents(), block until they return.
The PHP code after the PHP
file_get_contents() API function call does not
get executed until the PHP
file_get_contents() API function call either
completely succeeds or completely fails. There is no callback mechanism
for this PHP API.
The previous PHP statement is converted in the following
Node.js code. The
function in the
fs module is the
closest Node.js equivalent to the PHP