PHP fopen() with "wb" not working - php

Here is a snippet of what I'm trying to do:
$file = fopen($path, "wb");
fwrite($file, $data);
fclose($file);
Simple enough.
But when I open the created file, I see 0x0D inserted before 0x0A everywhere. I understand that this will happen if I open the file without binary mode.
But I've clearly specified I want binary mode. Maybe my brain isn't functioning right or something, so.. Anyone got a solution?

It turns out, for some weird reason, the problem was with my $path. My $path value was "temp".
It would generate the file named "temp" but would refuse to open it in binary mode. Giving the file an extension like "temp.bin" or "temp.tmp" allowed it to work in binary mode.
Problem solved for now but I'm still wondering why it works like this.

Seems the problem is with the $path. Please make sure you have given the correct file path.
If you are defining the $path with a dynamic file name, use / before the file name. For example, $var = "/var/www/html/projectFolder/folderFile/". "Filename.fileformat"
If you're working with URLs in a redirection context, then the root directory ('/') refers to your domain's root. The same goes for paths for linking files or images and for include and require directives.

You're making the classic mistake of confusing data with the representation of that data.
Let's say you have a text file. If you open it in Notepad, you'll see the following:
$str = "Hello world!";
echo bin2hex($str); // output: 48656c6c6f20776f726c6421
$file = fopen($path, "wb");
$data = bin2hex($data);
fwrite($file, $data);
fclose($file);

Related

Writing to file with fwrite appears successful, but no file appears

All I am attempting to do is append to a file, and then read the file. In this case, I am appending 'hi', so my results look like 'hi', 'hihi', 'hihihi', etc. This works. What is so baffling is that if I then look at my temp dir, I see no file /tmp/bb.txt. How am I able to append to a file I cannot find in my file system? Am I under some sort of fake root or something?
$content is becoming a longer string each time, so it must be saving somewhere. When I step through, $x is true.
public function testFileAction()
{
$file = '/tmp/bb.txt';
$x = file_exists($file);
$mf = fopen($file, 'a');
fwrite($mf, 'hi');
fclose($mf);
$mfr = fopen($file, 'r');
$content = fread($mfr, filesize($file));
fclose($mfr);
echo $content;
}
Code is correct.
How are you running this? File can be owned by user used by server (apache for example).
You (user in the terminal) probably don't have permission to read the file.
Try sudo ls /tmp.
The problem is that '/tmp' might not mean the actual path of '/tmp' to php. Linux can be configured in a way that each process has its own tmp directory that it uses separately from any other process.
https://blog.oddbit.com/post/2012-11-05-fedora-private-tmp/

PHP fopen doesn't find existing file

I'm currently writting a login-system with PHP, for that I need to read the files with some user-information in it.
But after changing the folder system, PHP fopen doesn't read the files anymore.
Both the users.php and userinf.csv files are in the samle folder.
I allready tried to change the filepath, hard-coded the filepath , recreated the file. All of which file.
//Read file
$fp = fopen("userinf.csv", "r");
if(!$fp)
{
echo "File couldn't be read";
return false;
}
Before changing the file system, it worked. But now I am geting the error:
Warning: fopen(userinf.csv): failed to open stream: No such file or directory in FILEPATH on line 45
When you use the fread function without any reference it could fail. I always say that you need to check your path first with getcwd()
<?php
echo getcwd(); //Current Working Directory
?>
Use absolute paths, always. It removes any ambiguity. Using a relative path may change based on where your script is located, among other things, depending on your system.
$fp = fopen("/home/somewhere/blah/userinf.csv", "r");
You can always use a variable for the path as well:
// Somewhere in your code
define('ROOT_PATH', "/home/somewhere/blah");
// In the implementation
$fp = fopen(ROOT_PATH . "/userinf.csv", "r");

file_put_contents stopped working

I have a PHP code that connects to a FTP server, reads a file's content, makes a minor change, and than overrides the original file.
it looks like:
$stream_context = stream_context_create(array('ftp' => array('overwrite' => true)));
$file_content = file_get_contents($ftp_file); // this line works
$file_content = str_replace('some content', 'another content', $file_content); // this also..
file_put_contents($ftp_file, $file_content, 0, $stream_context); // this one doesn't :/
the real issue is that the "file_put_contents" worked for a long time, but now it doesn't.
what it does now is weird: it deletes the original file from the server..
also, if i'm changing it to something like:
file_put_contents($new_ftp_file, $file_content);
from what I know, it should create the new file and put the content in it, but it doesn't create it at all.
the hosting service i'm using has a PHP version change a few days ago. I don't remember the what the previous version was, but the current is: 5.2.17
thanks! :)
some changes
I found this piece: http://www.php.net/manual/en/function.file-put-contents.php#86864
doting the same as "file_put_contents" but with foen, fwrite and fclose (I send his example because of the results..). his functions is returning "false" if it couldn't to "fopen" the file, or the "bytes" if it succeeded. I got "false" :/
which means it couldn't even do the:
#fopen($filename, 'w');
although the "file_get_contents" with the same file address is working.
reading is working (but if you take the $filename and use it yourself on a client FTP - it works):
#fopen($filename, 'r');
the "open base_dir" for my hosting (which makes the action) is set to false, but the target hosting (which has the target-file) is set to be true.
I had an idea to save the new content on a new file, so I tried something like:
$f = #fopen($new_ftp_file, 'w'); //this one seems to work and connect
fwrite($f, $file_content); // this one seems to work either and returning the number of byes..
fclose($f);
the problem is that none of them really works. I logged in to the FTP address, using the same credentials that my script is using, and I haven't found the new file. It wasn't created at all. (as I remind you, "$new_ftp_file" is a path to a file that doesn't exists, so "w" mode on "fopen" should create it).
file_put_contents do erase the file by default if it already exists. You have to ask him to don't.
Look at here:
http://www.php.net/manual/en/function.file-put-contents.php
See: If filename does not exist, the file is created. Otherwise, the existing file is overwritten, unless the FILE_APPEND flag is set.
this is not the best solution (definitely), but I managed to figure something..
I used 2 different hosts on them same hosting service, both of the having "open base_dir = On" & "safe mode = Off".
it looks something like:
$ftpstring = "ftp://user:password#anotherhosteddomain.com";
$file = file_get_contents($ftpstring . 'index.html'); // this line works as expected. (yeah, the other hosting has this file);
and then, if you're trying to write something like:
$handler = fopen($ftpstring.'index.html', "w");
it wouldn't work, and tell you it cannot access on writing mode to an existing file.
so if you're doing something like:
$newfile_handler = fopen($ftpstring.'index_new_version.html', "w");
fwrite($newfile, "1122");
so yeah - it works!
but now is a tricky issue.. when i'm adding this line:
fclose($newfile_handler);
the new file is deleted from the hosting!!
I couldn't find any reason why "fclose" is deleting the file after it was create at "fopen" and written in at "fwrite".
so if you're not adding the "fclose" line - it works, but it doesn't close the connection, and also I have to actually delete the existing file before I can override it with a new content, which makes it silly..
although it works, I would really like someone to give me a better solution than mine.

PHP fwrite() not working

I'm writing a function in php, client side I have a canvas image which I use toDataUrl() along with a file name to save the image on the server. The here's the code:
<?php
$imageData=$GLOBALS['HTTP_RAW_POST_DATA'];
$data = json_decode($imageData, true);
$file = $data["file"];
$image = $data["data"];
$filteredData=substr($image, strpos($image, ",")+1);
$unencodedData=base64_decode($filteredData);
$fp = fopen( 'image/' . $file , 'wb' );
fwrite( $fp, $unencodedData);
fclose( $fp );
?>
The thing is that this code works. And for two out of three of the pages I used it on it works fine. The problem is when I copy and pasted it a third time to implement it again, for some reason the file is made on the server except that no data get's written into the file. I don't think it's a problem client side because I write in a debug alert message in the javascript and a debug echo into the PHP and both are able to print out the data fine. I made this short debug file:
<?php
$fp = fopen('data.txt', 'wb');
if(is_writable('data.txt')){
echo "file is writable<br>";
}
if(fwrite($fp, 'test') == FALSE){
echo "failed to write data<br>";
}
fclose($fp);
?>
And the output is
file is writable
failed to write data
I've tried using chmod and setting everything, the folder, the text file before I write to it to 0777 and I still get the same result; the file is made but no data is written into it. Is there anything I'm missing or any other approaches that might help. I haven't found anything on google and am still baffled as to why the same code worked exactly as expected twice before suddenly stopping for no apparent reason.
Thanks in advance.
I know this is an old post, but I had a very similar problem and found a solution (for me at least)! I ran out of disk space on my server, so it could create a 0 byte file, but wouldn't write to it. After I cleared out some space (deleted a 13gb error.log file) everything started working again as expected.
If fopen works but fwrite mysteriously doesn't, check your disk space. 'df -h' is the command to check disk space on a linux server.
instead of $fp = fopen('data.txt', 'wb'); give $fp = fopen('data.txt', 'w'); and try
Changed "wb" to "w"
When you write $fp = fopen('data.txt', 'w'); for your domain website.com having root at /var/www/website/ and if the php file is located at /var/www/website/php/server/file/admin.php or something similar, it will actually create a file at /var/www/website/data.txt
Try giving absolute path or path relative to your domain root to create files like,
$fp = fopen('php/server/file/data.txt', 'w');
Try the find command to see if the file is created anywhere else in the folder directory by using the following in Ubuntu,
find /var/www/website/ -name 'data.txt'
I had this issue, probably can help you solve if you have similar issue.

How to get a temporary file path?

I know you can create a temporary file with tmpfile and than write to it, and close it when it is not needed anymore. But the problem I have is that I need the absolute path to the file like this:
"/var/www/html/lolo/myfile.xml"
Can I somehow get the path, even with some other function or trick?
EDIT:
I want to be able to download the file from the database, but without
$fh = fopen("/var/www/html/myfile.xml", 'w') or die("no no");
fwrite($fh, $fileData);
fclose($fh);
because if I do it like this, there is a chance of overlapping, if more people try to download the same file at exactly the same time. Or am I wrong?
EDIT2:
Maybe I can just generate unique(uniqID) filenames like that, and than delete them. Or can this be too consuming for the server if many people are downloading?
There are many ways you can achieve this, here is one
<?php
// Create a temp file in the temporary
// files directory using sys_get_temp_dir()
$temp_file = tempnam(sys_get_temp_dir(), 'MyFileName');
echo $temp_file;
?>
The above example will output something similar to:
/var/tmp/MyFileNameX322.tmp
I know you can create a temporary file with tmpfile
That is a good start, something like this will do:
$fileHandleResource = tmpfile();
Can I somehow get the path, even with some other function or trick?
Yes:
$metaData = stream_get_meta_data($fileHandleResource);
$filepath = $metaData['uri'];
This approach has the benefit of leaving it up to PHP to pick a good place and name for this temporary file, which could end up being a good thing or a bad thing depending on your needs. But it is the simplest way to do this if you don't yet have a specific reason to pick your own directory and filename.
References:
http://us.php.net/manual/en/function.stream-get-meta-data.php
Getting filename (or deleting file) using file handle
This will give you the directory. I guess after that you are on your own.
For newer (not very new lol) versions of PHP (requires php 5.2.1 or higher) #whik's answer is better suited:
<?php
// Create a temp file in the temporary
// files directory using sys_get_temp_dir()
$temp_file = tempnam(sys_get_temp_dir(), 'MyFileName');
echo $temp_file;
?>
The above example will output something similar to: /var/tmp/MyFileNameX322.tmp
old answer
Just in case someone encounters exactly the same problem. I ended up doing
$fh = fopen($filepath, 'w') or die("Can't open file $name for writing temporary stuff.");
fwrite($fh, $fileData);
fclose($fh);
and
unlink($filepath);
at the end when file is not needed anymore.
Before that, I generated filename like that:
$r = rand();
$filepath = "/var/www/html/someDirectory/$name.$r.xml";
I just generated a temporary file, deleted it, and created a folder with the same name
$tempFolder = tempnam(sys_get_temp_dir(), 'MyFileName');
unlink($tempFolder);
mkdir($tempFolder);

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