How to delete a certain line of a file in php

How to delete a certain line of a file in php: first define the operation file; then read the file data into an array; and finally delete the specified line of the existing text file.

The operating environment of this article: windows7 system, PHP7.1 version, DELL G3 computer

How to delete a certain line of a file with php?

PHP Delete any line of the text file or add a line

Delete the specified line of the actual existing text file. This line can be arbitrary, that is, it is decided by the user. Deleting any line in a text file is very meaningful. For example, we use a text file to record relevant information about registered users (one piece of information per line), and now we need to delete one of them.

<?php
$filename="aaa.txt";//定义操作文件
$delline=3; //要删除的行数
$farray=file($filename);//读取文件数据到数组中
for($i=0;$i<count($farray);$i++)
{   
    if(strcmp($i+1,$delline)==0)  //判断删除的行,strcmp是比较两个数大小的函数
    {   
        continue;
    }   
    if(trim($farray[$i])<>"")  //删除文件中的所有空行
    {   
        $newfp.=$farray[$i];    //重新整理后的数据
    }   
}   
$fp=@fopen($filename,"w");//以写的方式打开文件
@fputs($fp,$newfp);
@fclose($fp);
?>

The text file aaa.txt is as follows:

10.8.0.1:255.255.255.0
10.8.0.2:255.255.255.0
10.8.0.3:255.255.255.0
10.8.0.4:255.255.255.0
10.8.0.5:255.255.255.0
10.8.0.6:255.255.255.0
10.8.0.8:255.255.255.0

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