Append at the beginning of the file in PHP [duplicate] - php

Question

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Need to write at beginning of file with PHP
(10 answers)
Closed 9 years ago.
Hi I want to append a row at the beginning of the file using php.
Lets say for example the file is containing the following contnet:
Hello Stack Overflow, you are really helping me a lot.
And now i Want to add a row on top of the repvious one like this:
www.stackoverflow.com
Hello Stack Overflow, you are really helping me a lot.
This is the code that I am having at the moment in a script.
$fp = fopen($file, 'a+') or die("can't open file");
$theOldData = fread($fp, filesize($file));
fclose($fp);
$fp = fopen($file, 'w+') or die("can't open file");
$toBeWriteToFile = $insertNewRow.$theOldData;
fwrite($fp, $toBeWriteToFile);
fclose($fp);
I want some optimal solution for it, as I am using it in a php script. Here are some solutions i found on here:
Need to write at beginning of file with PHP
which says the following to append at the beginning:
<?php
$file_data = "Stuff you want to add\n";
$file_data .= file_get_contents('database.txt');
file_put_contents('database.txt', $file_data);
?>
And other one here:
Using php, how to insert text without overwriting to the beginning of a text file
says the following:
$old_content = file_get_contents($file);
fwrite($file, $new_content."\n".$old_content);
So my final question is, which is the best method to use (I mean optimal) among all the above methods. Is there any better possibly than above?
Looking for your thoughts on this!!!.

Answer 1

function file_prepend ($string, $filename) {
$fileContent = file_get_contents ($filename);
file_put_contents ($filename, $string . "\n" . $fileContent);
}
usage :
file_prepend("couldn't connect to the database", 'database.logs');

Answer 2

My personal preference when writing to a file is to use file_put_contents
From the manual:
This function is identical to calling fopen(), fwrite() and fclose()
successively to write data to a file.
Because the function automatically handles those three functions for me I do not have to remember to close the resource after I'm done with it.

Answer 3

There is no really efficient way to write before the first line in a file. Both solutions mentioned in your questions create a new file from copying everything from the old one then write new data (and there is no much difference between the two methods).
If you are really after efficiency, ie avoiding the whole copy of the existing file, and you need to have the last inserted line being the first in the file, it all depends how you plan on using the file after it is created.
three files
Per you comment, you could create three files header, content and footer and output each of them in sequence ; that would avoid the copy even if header is created after content.
work reverse in one file
This method puts the file in memory (array).
Since you know you create the content before the header, always write lines in reverse order, footer, content, then header:
function write_reverse($lines, $file) { // $lines is an array
for($i=count($lines)-1 ; $i>=0 ; $i--) fwrite($file, $lines[$i]);
}
then you call write_reverse() first with footer, then content and finally header. Each time you want to add something at the beginning of the file, just write at the end...
Then to read the file for output
$lines = array();
while (($line = fgets($file)) !== false) $lines[] = $line;
// then print from last one
for ($i=count($lines)-1 ; $i>=0 ; $i--) echo $lines[$i];
Then there is another consideration: could you avoid using files at all - eg via PHP APC

Answer 4

You mean prepending. I suggest you read the line and replace it with next line without losing data.
<?php
$dataToBeAdded = "www.stackoverflow.com";
$file = "database.txt";
$handle = fopen($file, "r+");
$final_length = filesize($file) + strlen($dataToBeAdded );
$existingData = fread($handle, strlen($dataToBeAdded ));
rewind($handle);
$i = 1;
while (ftell($handle) < $final_length)
{
fwrite($handle, $dataToBeAdded );
$dataToBeAdded = $existingData ;
$existingData = fread($handle, strlen($dataToBeAdded ));
fseek($handle, $i * strlen($dataToBeAdded ));
$i++;
}
?>