Can php modify file content?

php can modify the file content. Method: 1. Use the fopen() function to open the file, and use the fwrite() function to write data in the opened file to modify the file. 2. Directly use the file_put_contents() function to modify the file by clearing the file and adding data again or by adding data at the end of the file.

The operating environment of this tutorial: windows7 system, PHP version 7.1, DELL G3 computer

php can modify the file content. Here are several methods to introduce to you.

1. Use the fwrite() function

fwrite($handle, $string, $length) The function can write a string into the file. The fwrite() function can write the contents of $string to the file pointer $handle. If $length is specified, writing will stop when $length bytes have been written or $string has been written. If the function is successfully executed, the number of bytes written will be returned. If the function fails, FALSE will be returned.

Example 1: Clear the file and re-add data

<?php
header("Content-Type: text/html;charset=utf-8");    //设置字符编码
$file = "test.txt";
$handle = fopen($file, &#39;w&#39;);                 //打开文件
fwrite($handle, &#39;HELLO PHP!&#39;);    //写入内容
fclose($handle);//关闭文件
readfile($file);   //读取并输出文件全部内容
?>

Example 2: Add data at the end of the file

<?php
header("Content-Type: text/html;charset=utf-8");    //设置字符编码
$file = "test.txt";
$handle = fopen($file, &#39;a&#39;);                 //以追加写入的模式打开文件
fwrite($handle, &#39;https://www.php.cn/&#39;);    //写入内容
fclose($handle);//关闭文件
readfile($file);   //读取并输出文件全部内容
?>

2. Use the file_put_contents() function

file_put_contents($filename,$data,$mode,$context)The function can write a string to a file and accepts two required parameters $filename (the file to be opened) and $data (the content to be inserted, which can be a string, one-dimensional array or resource type), two omissible parameters $mode and $context (the environment of the file handle).

Among them, the $mode parameter is used for how to open/write files (i.e. file mode). It has three values:

• ##FILE_USE_INCLUDE_PATH: Default value, used to overwrite the original There is data.

• FILE_APPEND: If file $filename already exists, append data instead of overwriting.

• LOCK_EX: Obtain an exclusive lock while writing.

Example 1: Clear the file and re-add data

<?php
header("Content-Type: text/html;charset=utf-8");    //设置字符编码
$file = "test.txt";
file_put_contents($file, &#39;欢迎来到PHP中文网！&#39;);    //写入内容
readfile($file);   //读取并输出文件全部内容
?>

Example 2: Add data at the end of the file

<?php
header("Content-Type: text/html;charset=utf-8");    //设置字符编码
$file = "test.txt";
file_put_contents($file, &#39;欢迎来到PHP中文网！&#39;,FILE_APPEND);    //在文件结尾写入内容
readfile($file);   //读取并输出文件全部内容
?>

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