Commenting PHP codes

[boneXXX]

Could some one comment this codes what they do please? I found it on the web and I want to understand it. Thanks in advance.

 

<?php 
$fname = "test.txt"; 
$exclude = "some string"; 
$lines = file($fname); 
$out = ""; 
foreach ($lines as $line) { 
  if (strstr($line, $exclude) == "") { 
   $out .= $line; 
  } 
} 
$f = fopen($fname, "w"); 
fwrite($f, $out); 
fclose($f); 
?>

[mpharo]

Could some one comment this codes what they do please? I found it on the web and I want to understand it. Thanks in advance.

 

<?php 

//sets the file you want to read
$fname = "test.txt"; 
//excludes a string from the modification
$exclude = "some string"; 
//puts the opened file into array $lines
$lines = file($fname); 
//sets up $out as empty variable
$out = ""; 
//sets up the loop
foreach ($lines as $line) { 
//if it is equal to nothing after the excluded string $out equals the first part of the string
  if (strstr($line, $exclude) == "") { 
   $out .= $line; 
  } 
} 
//reopens the file with write permissions
$f = fopen($fname, "w"); 
//writes the file with the changes that were made above
fwrite($f, $out); 
//closes the file
fclose($f); 
?>

[boneXXX]

Thanks a lot it is perfect.

[boneXXX]

It is close to what I am looking for but not exactly.

 

I am trying to find a specific line, which starts with a unique word, to delete in a .txt file then rewrite that line. Could you help me on this please ?

 

I am ok till finding the line but don't know how to delete and rewrite it?