I have a little php script that removes the last character of a file.
$contents = file_get_contents($path);
rtrim($contents);
$contents = substr($contents, 0, -1);
$fh = fopen($path, 'w') or die("can't open file");
fwrite($fh, $contents);
fclose($fh);
So it reads in the file contents, strips off the last character and then truncates the file and writes the string back to it.
This all works fine.
My worry is that this file could contain a lot of data and the file_get_contents() call would then hold all this data in memory which could potentially max out my servers memory.
Is there a more efficient way to strip the last character from a file?
Thanks
Try this
$fh = fopen($path, 'r+') or die("can't open file");
$stat = fstat($fh);
ftruncate($fh, $stat['size']-1);
fclose($fh);
For more help see this
Related
I am trying to write to a file and then read the data from the same file. But sometimes I am facing this issue that the file reading process is getting started even before the file writing gets finished. How can I solve this issue ? How can i make file writing process finish before moving ahead?
// writing to file
$string= <12 kb of specific data which i need>;
$filename.="/ttc/";
$filename.="datasave.html";
if($fp = fopen($filename, 'w'))
{
fwrite($fp, $string);
fclose($fp);
}
// writing to the file
$handle = fopen($filename, "r") ;
$datatnc = fread($handle, filesize($filename));
$datatnc = addslashes($datatnc);
fclose($handle);
The reason it does not work is because when you are done writing a string to the file the file pointer points to the end of the file so later when you try to read the same file with the same file pointer there is nothing more to read. All you have to do is rewind the pointer to the beginning of the file. Here is an example:
<?php
$fileName = 'test_file';
$savePath = "tmp/tests/" . $fileName;
//create file pointer handle
$fp = fopen($savePath, 'r+');
fwrite($fp, "Writing and Reading with same fopen handle!");
//Now rewind file pointer to start reading
rewind($fp);
//this will output "Writing and Reading with same fopen handle!"
echo fread($fp, filesize($savePath));
fclose($fp);
?>
Here is more info on the rewind() method http://php.net/manual/en/function.rewind.php
I have mentioned the URL through which i got the solution. I implemented the same. If you want me to copy the text from that link then here it is :
$file = fopen("test.txt","w+");
// exclusive lock
if (flock($file,LOCK_EX))
{
fwrite($file,"Write something");
// release lock
flock($file,LOCK_UN);
}
else
{
echo "Error locking file!";
}
fclose($file);
Use fclose after writing to close the file pointer and then fopen again to open it.
I want to filter one text file by writing the results to a second text file.
I have a little bit of code and it doesn't work like it should work, it is only writing the LAST line of the first text file into a separate backup text file.
Code:
//filter the ingame bans
$search = "permanently";
$logfile = "ban_list.txt";
$timestamp = time();
// Read from file
$file = fopen($logfile, "r");
while( ($line = fgets($file) )!= false)
{
if(stristr($line,$search))
{
$cache_ig = "ingamebanlist.txt";
$fh = fopen($cache_ig, 'w') or die("can't open file");
$content = "\n";
fwrite($fh, $content);
$content = $line;
fwrite($fh, $content);
fclose($fh);
}
}
I personally do not see any errors in my code, please help.
REMEMBER: It does kind of work, but it only writes the LAST line of the ban_list.txt file into the ingamebanlist.txt file...
What happens with your code is that you open(using write mode), write and close inside your loop so it will only ever write 1 entry then overwrite it until the last entry, thus only saving the last item.
What you want is to have it outside the loop like this:
<?php
$search = "permanently";
$logfile = "ban_list.txt";
$cache_ig = "ingamebanlist.txt";
$timestamp = time();
$read = fopen($logfile, "r") or die("can't read file");
$write = fopen($cache_ig, 'w') or die("can't write to file");
while(($line = fgets($read)) !== false)
{
if(stristr($line,$search))
{
fwrite($write, $line . "\n");
}
}
fclose($write);
fclose($read);
An alternative solution would be to use a instead of w at your fopen since w will:
Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.
While a will:
Open for writing only; place the file pointer at the end of the file. If the file does not exist, attempt to create it.
Which would allow your code to work as is without any changes but the line:
$fh = fopen($cache_ig, 'w') or die("can't open file");
To:
$fh = fopen($cache_ig, 'a') or die("can't open file");
In PHP im creating a tool to open txt file with an integer in it, increment the number, save the number to a variable and then save and close the file. this is the code i have for it and it doesnt seem to work when i have it on my test server. Can anyone clue me in as to why this isnt working properly?
//opens pclnumber.txt to $handle, saves number to $number, Increments number in text file, saves and closes file
$handle = fopen("pclnumber.txt", "w+");
$number = fread($handle);
fwrite($handle, $number+1);
fclose($handle);
over all you must set reading permission on your file, and than you can use the follow code:
$filename = "pclnumber.txt";
//read file content
$handle = fopen($filename, "r");
$number = fread($handle, sizeof($filename));
fclose($handle);
//update file content
$handleWrite = fopen($filename, "w+");
fwrite($handleWrite, $number+1);
fclose($handleWrite);
Bye,
Marco
So basically, I have a form that opens a php file when submitted, i have the php writing to a file, but it will not continue adding values, the text file only has one "1" inside of it when it is supposed to have a "1" inside for every time the form has been submitted. Here is my code.
<?php
$myFile = "Data.txt";
$fh = fopen($myFile, 'w') or die("can't open file");
$stringData = "1";
fwrite($fh, $stringData);
fclose($fh);
?>
Any ideas?
Either open in append only format as Robert Rozas stated: fopen($myFile, 'a+');
Or get the contents and do the append manually some pseudo[esk]-code:
$contents = file_get_contents("somefile.txt");
//generate what to write
$contents .= $whatIGenerated;
$success = file_put_contents("somefile.txt", $contents);
Change this one line to this:
$fh = fopen($myFile, 'a') or die("can't open file");
Using w means write, using a means append.
I want to write a line to the end of the file.
My code is:
$myFile = "serialkey.txt";
$fh = fopen($myFile, 'w');
$space = "\r\n";
$stringData = "my new data";
fwrite($fh, $stringData.$space);
fclose($fh);
But when I used this code it deleted all the file and replace "my new data", I want it will not delete my file and append my data to it.
You have it set to write instead of append in
$fh = fopen($myFile, 'w');
It should be
$fh = fopen($myFile, 'a');
Hope this helps.
To insert text without over-writing the end of the file, you'll have to open it for appending (a+ rather than w)
$fh = fopen($myFile, 'a+');