I have this very simple program in PHP that does not want to work. It returns the same error as topic for unknown reasons to me.
$file = 'counter.txt';
$counter = file_get_contents($file);
if(flock($file, LOCK_EX)){
$counter += 1;
echo $counter;
$write = fopen($file, 'w') or die('Unable');
fwrite($write, $counter);
flock($file,LOCK_UN);
}
You have a few things out of order,
$file = 'counter.txt';
$counter = file_get_contents($file);
$write = fopen($file, 'w') or die('Unable'); //move this line
if(flock($write, LOCK_EX)){ //-- change this
$counter += 1;
echo $counter;
fwrite($write, $counter);
flock($write,LOCK_UN); //-- change this
}
The main problem is flock takes a (stream)resource as it's input, and the filename is just a string. So instead of $file you just need to use $write which is your file handle (resource), and then move fopen before the flock call.
If you are writing a single line do this instead
$file = 'counter.txt';
$counter += 1;
if(!file_put_contents($file, $counter, LOCK_EX)) or die('Unable');
http://php.net/manual/en/function.file-put-contents.php
It's pretty much equivalent to what you have there. Well except it's way shorter 3 vs 9 lines, easier, and Kooler.
I could even reduce this further down to 1 line:
if(!file_put_contents('counter.txt', ++$counter, LOCK_EX)) or die('Unable');
The LOCK_EX flag is Lock exclusive, basically the same thing as flock, just in this case PHP handles all the file stream stuff for you.
The real difference is if you do this in a loop, it's expensive getting file handles so to loop output into file_put_content is way less efficient then to open the file (outside the loop) and write to the same handle during inside a loop.
Hesse the reason I said this above.
If you are writing a single line do this instead
Hope that makes sense.
Based on laracasts
Solution was to give Apache group (www-data) read and write permissions to /storage/framework/cache applying recursively.
Related
I'm trying to make a download counter in a website for a video game in PHP, but for some reason, instead of incrementing the contents of the downloadcount.txt file by 1, it takes the number, increments it, and appends it to the end of the file. How could I just make it replace the file contents instead of appending it?
Here's the source:
<?php
ob_start();
$newURL = 'versions/v1.0.0aplha/Dungeon1UP.zip';
//header('Location: '.$newURL);
//increment download counter
$file = fopen("downloadcount.txt", "w+") or die("Unable to open file!");
$content = fread($file,filesize("downloadcount.txt"));
echo $content;
$output = (int) $content + 1;
//$output = 'test';
fwrite($file, $output);
fclose($file);
ob_end_flush();
?>
The number in the file is supposed to increase by one every time, but instead, it gives me numbers like this: 101110121011101310111012101110149.2233720368548E+189.2233720368548E+189.2233720368548E+18
As correctly pointed out in one of the comments, for your specific case you can use fseek ( $file, 0 ) right before writing, such as:
fseek ( $file, 0 );
fwrite($file, $output);
Or even simpler you can rewind($file) before writing, this will ensure that the next write happens at byte 0 - ie the start of the file.
The reason why the file gets appended it is because you're opening the file in append and truncate mode, that is "w+". You have to open it in readwrite mode in case you do not want to reset the contents, just "r+" on your fopen, such as:
fopen("downloadcount.txt", "r+")
Just make sure the file exists before writing!
Please see fopen modes here:
https://www.php.net/manual/en/function.fopen.php
And working code here:
https://bpaste.net/show/iasj
It will be much simpler to use file_get_contents/file_put_contents:
// update with more precise path to file:
$content = file_get_contents(__DIR__ . "/downloadcount.txt");
echo $content;
$output = (int) $content + 1;
// by default `file_put_contents` overwrites file content
file_put_contents(__DIR__ . "/downloadcount.txt", $output);
That appending should just be a typecasting problem, but I would not encourage you to handle counts the file way. In order to count the number of downloads for a file, it's better to make a database update of a row using transactions to handle concurrency properly, as doing it the file way could compromise accuracy.
You can get the content, check if the file has data. If not initialise to 0 and then just replace the content.
$fileContent = file_get_contents("downloadcount.txt");
$content = (!empty($fileContent) ? $fileContent : 0);
$content++;
file_put_contents('downloadcount.txt', $content);
Check $str or directly content inside the file
This question already has answers here:
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!!!.
function file_prepend ($string, $filename) {
$fileContent = file_get_contents ($filename);
file_put_contents ($filename, $string . "\n" . $fileContent);
}
usage :
file_prepend("couldn't connect to the database", 'database.logs');
My personal preference when writing to a file is to use file_put_contents
From the manual:
This function is identical to calling fopen(), fwrite() and fclose()
successively to write data to a file.
Because the function automatically handles those three functions for me I do not have to remember to close the resource after I'm done with it.
There is no really efficient way to write before the first line in a file. Both solutions mentioned in your questions create a new file from copying everything from the old one then write new data (and there is no much difference between the two methods).
If you are really after efficiency, ie avoiding the whole copy of the existing file, and you need to have the last inserted line being the first in the file, it all depends how you plan on using the file after it is created.
three files
Per you comment, you could create three files header, content and footer and output each of them in sequence ; that would avoid the copy even if header is created after content.
work reverse in one file
This method puts the file in memory (array).
Since you know you create the content before the header, always write lines in reverse order, footer, content, then header:
function write_reverse($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
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++;
}
?>
I am trying to use a php call through AJAX to replace a single line of a .txt file, in which I store user-specific information. The problem is that if I use fwrite once getting to the correct line, it leaves any previous information which is longer than the replacement information untouched at the end. Is there an easy way to clear a single line in a .txt file with php that I can call first?
Example of what is happening - let's say I'm storing favorite composer, and a user has "Beethoven" in their .txt file, and want's to change it to "Mozart", when I used fwrite over "Beethoven" with "Mozart", I am getting "Mozartven" as the new line. I am using "r+" in the fopen call, as I only want to replace a single line at a time.
If this configuration data doesn't need to be made available to non-PHP apps, consider using var_export() instead. It's basically var_dump/print_r, but outputs the variable as parseable PHP code. This'd reduce your code to:
include('config.php');
$CONFIG['musician'] = 'Mozart';
file_put_contents('config.php', '<?php $CONFIG = ' . var_export($CONFIG, true));
This is a code I've wrote some time ago to delete line from the file, it have to be modified. Also, it will work correctly if the new line is shorter than the old one, for longer lines heavy modification will be required.
The key is the second while loop, in which all contents of the file after the change is being rewritten in the correct position in the file.
<?php
$size = filesize('test.txt');
$file = fopen('test.txt', 'r+');
$lineToDelete = 3;
$counter = 1;
while ($counter < $lineToDelete) {
fgets($file); // skip
$counter++;
}
$position = ftell($file);
$lineToRemove = fgets($file);
$bufferSize = strlen($lineToRemove);
while ($newLine = fread($file, $bufferSize)) {
fseek($file, $position, SEEK_SET);
fwrite($file, $newLine);
$position = ftell($file);
fseek($file, $bufferSize, SEEK_CUR);
}
ftruncate($file, $size - $bufferSize);
echo 'Done';
fclose($file);
?>
I want to split huge files (to be specific, tar.gz files) in multiple part from php code. Main reason to do this is, php's 2gb limit on 32bit system.
SO I want to split big files in multiple part and process each part seperately.
Is this possible? If yes, how?
My comment was voted up twice, so maybe my guess was onto something :P
If on a unix environment, try this...
exec('split -d -b 2048m file.tar.gz pieces');
split
Your pieces should be pieces1, pieces2, etc.
You could get the number of resulting pieces easily by using stat() in PHP to get the file size and then do the simple math (int) ($stat['size'] / 2048*1024*1024) (I think).
A simple method (if using Linux based server) is to use the exec command and to run the split command:
exec('split Large.tar.gz -b 4096k SmallParts'); // 4MB parts
/* | | | | |
| | |______| |
App | | |_____________
The source file | |
The split size Out Filename
*/
See here for more details: http://www.computerhope.com/unix/usplit.htm
Or you can use: http://www.computerhope.com/unix/ucsplit.htm
exec('csplit -k -s -f part_ -n 3 LargeFile.tar.gz');
PHP runs within a single thread and the only way to increase this thread count is to create child process using the fork commands.
This is not resource friendly. What I would suggest is to look into a language that can do this fast and effectively. I would suggest using node.js.
Just install node on the server and then create a small script, called node_split for instance, that can do the job on its own for you.
But I do strongly advise that you do not use PHP for this job but use exec to allow the host operating system to do this.
HJSPLIT
http://www.hjsplit.org/php/
PHP itself might not be able to...
If you can figure out how to do this from your computers' command line,
You should be able to then execute these commands using exec();
function split_file($source, $targetpath='/split/', $lines=1000){
$i=0;
$j=1;
$date = date("m-d-y");
$buffer='';
$handle = fopen ($_SERVER['DOCUMENT_ROOT'].$source, "r");
while (!feof ($handle)) {
$buffer .= fgets($handle, 4096);
$i++;
if ($i >= $lines) {
$fname = $_SERVER['DOCUMENT_ROOT'].$targetpath."part_".$date.$j.".txt";
$fhandle = fopen($fname, "w") or die($php_errormsg);
if (!$fhandle) {
echo "Cannot open file ($fname)";
//exit;
}
if (!fwrite($fhandle, $buffer)) {
echo "Cannot write to file ($fname)";
//exit;
}
fclose($fhandle);
$j++;
$buffer='';
$i=0;
$line+=10; // add 10 to $lines after each iteration. Modify this line as required
}
}
fclose ($handle);
}
$handle = fopen('source/file/path','r');
$f = 1; //new file number
while(!feof($handle))
{
$newfile = fopen('newfile/path/'.$f.'.txt','w'); //create new file to write to with file number
for($i = 1; $i <= 5000; $i++) //for 5000 lines
{
$import = fgets($handle);
//print_r($import);
fwrite($newfile,$import);
if(feof($handle))
{break;} //If file ends, break loop
}
fclose($newfile);
$f++; //Increment newfile number
}
fclose($handle);
If you want to split files which are
already on server, you can do it
(simply use the file functions fread,
fopen, fwrite, fseek to read/write
part of the file).
If you want to
split files which are uploaded from
the client, I am afraid you cannot.
This would probably be possible in php, but php was built for web development and trying to this whole operation in one request will result in the request timing out.
You could however use another language like java or c# and build a background process that you can notify from php to perform the operation. Or even run from php, depending on your Security settings on the host.
Splits are named as filename.part0 filename.part1 ...
<?php
function fsplit($file,$buffer=1024){
//open file to read
$file_handle = fopen($file,'r');
//get file size
$file_size = filesize($file);
//no of parts to split
$parts = $file_size / $buffer;
//store all the file names
$file_parts = array();
//path to write the final files
$store_path = "splits/";
//name of input file
$file_name = basename($file);
for($i=0;$i<$parts;$i++){
//read buffer sized amount from file
$file_part = fread($file_handle, $buffer);
//the filename of the part
$file_part_path = $store_path.$file_name.".part$i";
//open the new file [create it] to write
$file_new = fopen($file_part_path,'w+');
//write the part of file
fwrite($file_new, $file_part);
//add the name of the file to part list [optional]
array_push($file_parts, $file_part_path);
//close the part file handle
fclose($file_new);
}
//close the main file handle
fclose($file_handle);
return $file_parts;
}
?>
So i've been trying to write this little piece of code to read a file (status.txt), search it for 1 of 4 keywords and loop until either time runs out (5 minutes) or it finds one of the words. I've already written a few simple php scripts to write the words to a txt file, but I can't seem to get this part to work. It either doesn't clear the file in the beginning or seems to hang and never picks up the changes. Any advice would be hugely helpful.
<?php
//Variables
$stringG = "green";
$stringR = "red";
$stringB = "blue";
$stringO = "orange";
$clear = "";
$statusFile = "status.txt";
//erase file
$fh = fopen($statusFile, 'w'); //clear the file with "clear"
fwrite($fh, $clear);
fclose($fh);
//Insert LOOP
$counter = 0;
while ( $counter <= 10 ) {
//echo "loop begun";
// Read THE FILE
$fh = fopen($statusFile, 'r');
$data = fread($fh, filesize($statusFile));
fclose($fh);
//process the file
if(stristr($data,$stringG)) {
echo "Green!";
$counter = $counter + 30; //stop if triggered
}
elseif (stristr($data,$stringR)) {
echo "Red";
$counter = $counter + 30; //stop if triggered
}
elseif (stristr($data,$stringB)) {
echo "Blue";
$counter = $counter + 30; //stop if triggered
}
elseif (stristr($data,$stringO)) {
echo "Orange";
$counter = $counter + 30; //stop if triggered
}
else {
//increment loop counter
$counter = $counter + 1;
//Insert pause
sleep(10);
}
}
?>
You should open the file before your read loop, and close it after the loop. As in :
open the file
loop through the lines in the file
close the file
Also, if you clear the file before you read it, isn't it going to be empty every time?
Well, first of all, you don't need to "clear" the file this way... The "w" option in fopen will already do that for you.
Also, I wouldn't try to read the whole file at once, because, if it's very large, that won't work without intense memory usage.
What you should do is read the file sequentially, which means you always read a fixed amount of bytes and look for the keywords. To avoid losing keywords which are cut in half by your reading mechanism, you could make your reads overlay a bit (the length of your longest keyword-1), to solve that problem.
Then you should modify your while loop so that it also checks if you are at the end of the file ( while(!feof($fh)) ).
PS: It has been mentioned that you clear your file before reading it. What I understood is that your file gets a lot of input really fast, so you expect it to already have content again when you reopen it. If that's not the case, you really need to rethink your logic ;)
PPS: You don't need to abort your while loop by incrementing your counter variable past the boundaries you define. You can also use the break-keyword.
You haven't included the code which deletes the file in the while loop, so it only clears the file once. Also, I'd use unlink($statusFile); to delete the file.
You should rather use for cycle. And to your problem - you clear the file, then get the data from it. Try dumping this $data, you'll end up with string(0) "" for sure. First, save the data, then clear the file.
Edit: If you are changing the file in the loop itself in another thread, there's another problem. You should look after anatomic file stream. For example, you can use Nette SafeStream class.