读取文件中的所有行并删除包含某些字符串的行

Question

I'm rather new to PHP, and was trying to remove all lines where any instance of the string variable 'user' appears. My current code

if($action == "removeUser")
{
foreach(file('users.txt') as $line) 
{
    if (strpos($line, $parameters) !== false) 
    {
        $line = "";
    }
}
}

For some reason this doesn't seem to have any effect at all. What am I doing wrong?

Answer 1

You need to open the file and read the lines.

<?php

if($action == "removeUser")
{
    $filename = "users.txt";

    // Open your file
    $handle = fopen($filename, "r");

    $new_content='';

    echo "Valid input: <br><br>";
    // Loop through all the lines
    while( $line = fgets($handle) )
    {

      //try to find the string 'user' - Case-insensitive 
      if(stristr($line,"user")===FALSE)
      {
        // To remove white spaces
        $line=trim($line);

        if($line!='') echo $line."<br>";

       //if doesn't contain the string "user", 
       // add it to new input           
        $new_content.=$line."
"; 
      }
    }

    // closes the file
    fclose($handle);

    $new_content=trim($new_content); // Remove the 
 from the last line

    echo "<br>Updating file with new content...";
    file_put_contents($filename,$new_content);
    echo "Ok";
}

?>