New file reading symbols in PHP8.1

PHP8.1 new file reading symbols

The release of PHP8.1 version brings many exciting features and improvements, one of which is the improvement of the file reading function. In this version, new file reading symbols are introduced, making file reading more convenient and flexible. This article will introduce the new file reading symbols in PHP8.1 and provide some code examples to demonstrate its usage.

Traditionally, PHP uses the fopen function to open a file, and then uses the fread function to read the file contents line by line. Although this method is feasible, it is cumbersome to operate, especially when the file is large or multiple files need to be read.

In PHP8.1, the file reading symbol << was introduced, which allows us to read the file content in a more concise and smooth way. Here is a basic example of using a file to read symbols:

$file = fopen('example.txt', 'r');
$content = <<file
$file
file;

echo $content;
fclose($file);

In the above example, we first opened a file called example.txt using the fopen function file, and the read mode 'r' is specified. Next, we use the file reading symbol << to read the contents of the file. It should be noted that the use of the file reading symbol requires an identifier after the symbol to represent the file handle to be read. In this example, we use the file handle $file as the identifier.

File reading symbol<< uses an output buffer internally, so we can directly assign it to a variable $content without calling freadFunction. Finally, we display the contents of the file by printing $content. Finally, we use the fclose function to close the file handle and release the resources.

In addition to the mode 'r' used in the above example, the file reading notation << also supports other reading modes, including 'w', 'a' and 'x' etc. Here is an example using 'w' mode:

$file = fopen('example.txt', 'w');
$content = <<file
This is a sample text.
This text will be written to the file.
file;

fwrite($file, $content);
fclose($file);

In the above example, we open a file in write mode 'w' and use File reading symbol <<Reads the contents of variable $content. We then write the contents to the file using the fwrite function and finally close the file handle.

In addition to basic file reading functions, file reading symbols<< also support some advanced features, such as the use of line number symbols when reading file contents __LINE__ and file name symbols __FILE__. Here is an example that demonstrates how to use these symbols:

$file = fopen('example.txt', 'r');
$content = <<file
This is line 1, current line number is: __LINE__
This is line 2, current line number is: __LINE__
This is line 3, current line number is: __LINE__

This file name is: __FILE__
file;

echo $content;
fclose($file);

In the above example, we use the file reading symbols << to read the file content and in the text The line number symbol __LINE__ and the file name symbol __FILE__ are inserted. When reading the file contents, these symbols will be replaced with the current line number and file name. Finally, we display the contents of the file by printing $content.

To summarize, the new file reading symbols in PHP8.1<< make file reading more convenient and flexible. By using file reading symbols, we can read file contents in a more concise and smooth way, and can conveniently manipulate file handles and other symbols during the reading process. Hopefully the examples and explanations provided in this article will help you take full advantage of the file reading notation in PHP 8.1.

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