PHP Example Tutorial: File Operation Skills - Implementation of Reading and Writing Functions

In PHP programming, it is often necessary to read and write files. . This article will introduce how to use PHP to implement file reading and writing functions, and attach relevant code examples.

1. File reading

In PHP, you can use the file_get_contents() function to read the file contents. This function reads the entire file contents into a string and returns the string.

The following is a sample code that reads the contents of a file and outputs it:

<?php
$file = 'example.txt';
$content = file_get_contents($file);

echo $content;
?>

In the above code, we assign the file name to the variable $file, and then use file_get_contents()The function reads the file contents and assigns the result to the variable $content. Finally, use the echo statement to output the file contents.

In addition to using the file_get_contents() function, you can also use the fopen() function to open the file, and the fread() function to Read the file contents.

The following is a sample code that uses the fopen() and fread() functions to read the contents of a file:

<?php
$file = 'example.txt';
$handle = fopen($file, 'r');
$content = fread($handle, filesize($file));

echo $content;

fclose($handle);
?>

In the above code, We use the fopen() function to open the file and assign the returned file resource to the variable $handle. Then, use the fread() function to read the file content and assign the result to the variable $content. Finally, use the echo statement to output the file contents.

2. File writing

In PHP, you can use the file_put_contents() function to write file contents. This function writes a string to the specified file and returns the number of bytes written.

The following is a sample code that writes a string to a file and outputs the result:

<?php
$file = 'example.txt';
$content = 'Hello, world!';

$bytes_written = file_put_contents($file, $content);

echo 'Bytes written: ' . $bytes_written;
?>

In the above code, we assign the file name to the variable $file, The string is assigned to variable $content. Then, use the file_put_contents() function to write the string to the file, and assign the number of bytes written to the variable $bytes_written. Finally, use the echo statement to output the number of bytes written.

In addition to using the file_put_contents() function, you can also use the fopen() function to open the file, and the fwrite() function to Write file contents.

The following is a sample code that uses the fopen() and fwrite() functions to write the contents of a file:

<?php
$file = 'example.txt';
$content = 'Hello, world!';

$handle = fopen($file, 'w');
$bytes_written = fwrite($handle, $content);

echo 'Bytes written: ' . $bytes_written;

fclose($handle);
?>

In the above code, We use the fopen() function to open the file and assign the returned file resource to the variable $handle. Then, use the fwrite() function to write the file content, and assign the number of written bytes to the variable $bytes_written. Finally, use the echo statement to output the number of bytes written.

Summary:

Through the introduction and sample code of this article, we have learned how to use PHP to implement file reading and writing functions. Whether using the file_get_contents() and file_put_contents() functions, or using the fopen() and fread(), fwrite () function is very convenient for file operations. According to actual needs, choosing the appropriate method to read and write files can better complete related tasks.

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