I'm trying to serve a file for download to a user, and I'm having trouble with fpassthru. The function I'm using to download a file is:
http://pastebin.com/eXDpgUqq
Note that the file is successfully created from a blob, and is in fact the file I want the user to download. The script exits successfully, and reports no errors, but the file is not downloaded. I can't for the life of me think what's wrong.
EDIT: I removed the error suppression from fopen(), but it still reports no error. Somehow the data in the output buffer is never being told to be downloaded by the browser.
I tried your code (without the blob part), and it worked fine. I can download a binary file. Based on my experience, here are something to check:
Has the file been completely saved before you initiate the reading? Check the return value of file_put_contents.
How large is the file? fpassthru reads the whole file into memory. If the file is too large, memory might be insufficient. Please refer to http://board.phpbuilder.com/showthread.php?10330609-RESOLVED-php-driven-file-download-using-fpassthru for more information.
Instead of downloading the file to local server (reading the whole file into server’s memory, and letting the client download the file from the server), you can create an SAS URL, and simply redirect the browser to the URL. Azure will take care of download automatically. You many want to refer to http://blogs.msdn.com/b/azureossds/archive/2015/05/12/generating-shared-access-signature-sas-using-php.aspx for a sample.
I was able to download the file by passing a stream obtained with the Azure API directly to fpassthru, without creating a file. Unfortunately, I can't show the code because it belongs to a project that I have finished working on and the code is no longer available to me.
Related
I'm trying to archive a big file using PHP and send it to the browser for download. The problem is the file is located on a remote machine and the only way to get it is via HTTP. So imagine this is my file: https://dropboxcontent.com/user333/3yjdsgf/video1.mp4
It's a direct link and I can download the file using wget, or curl anything. When a user wants to download it, I first fetch the file to the server, then zip it up and then send it to the user. Well, if the file is really large, the user has to sit there waiting for the server to download it before he sees the download dialog box in his browser. Is there a way for me to start the download of the file https://dropboxcontent.com/user333/3yjdsgf/video1.mp4 (let's say I'm downloading it into a local /tmp/video.mp4) and simultaneously start putting into an archive and streaming it into the user's browser?
I'm using this library to zip it up: https://github.com/barracudanetworks/ArchiveStream-php, which works great, but the bottleneck is still fetching the file to the server's local filesystem.
Here is my code:
$f = file_get_contents("https://dropboxcontent.com/user333/3yjdsgf/video1.mp4");
$zip->add_file('big/hello.mp4', $f);
The problem is line $f = file_get_contents("https://dropboxcontent.com/user333/3yjdsgf/video1.mp4"); takes too long if the file is really big.
As suggested in the comments of the original post by Touch Cat Digital Inc, I found the answer here: https://stackoverflow.com/a/6914986/1927991
A chunked stream of the remote file was the answer. Very clever.
My application is keeping watch on a set of folders where users can upload files. When a file upload is finished I have to apply a treatment, but I don't know how to detect that a file has not finish to upload.
Any way to detect if a file is not released yet by the FTP server?
There's no generic solution to this problem.
Some FTP servers lock the file being uploaded, preventing you from accessing it, while the file is still being uploaded. For example IIS FTP server does that. Most other FTP servers do not. See my answer at Prevent file from being accessed as it's being uploaded.
There are some common workarounds to the problem (originally posted in SFTP file lock mechanism, but relevant for the FTP too):
You can have the client upload a "done" file once the upload finishes. Make your automated system wait for the "done" file to appear.
You can have a dedicated "upload" folder and have the client (atomically) move the uploaded file to a "done" folder. Make your automated system look to the "done" folder only.
Have a file naming convention for files being uploaded (".filepart") and have the client (atomically) rename the file after upload to its final name. Make your automated system ignore the ".filepart" files.
See (my) article Locking files while uploading / Upload to temporary file name for an example of implementing this approach.
Also, some FTP servers have this functionality built-in. For example ProFTPD with its HiddenStores directive.
A gross hack is to periodically check for file attributes (size and time) and consider the upload finished, if the attributes have not changed for some time interval.
You can also make use of the fact that some file formats have clear end-of-the-file marker (like XML or ZIP). So you know, that the file is incomplete.
Some FTP servers allow you to configure a hook to be called, when an upload is finished. You can make use of that. For example ProFTPD has a mod_exec module (see the ExecOnCommand directive).
I use ftputil to implement this work-around:
connect to ftp server
list all files of the directory
call stat() on each file
wait N seconds
For each file: call stat() again. If result is different, then skip this file, since it was modified during the last seconds.
If stat() result is not different, then download the file.
This whole ftp-fetching is old and obsolete technology. I hope that the customer will use a modern http API the next time :-)
If you are reading files of particular extensions, then use WINSCP for File Transfer. It will create a temporary file with extension .filepart and it will turn to the actual file extension once it fully transfer the file.
I hope, it will help someone.
This is a classic problem with FTP transfers. The only mostly reliable method I've found is to send a file, then send a second short "marker" file just to tell the recipient the transfer of the first is complete. You can use a file naming convention and just check for existence of the second file.
You might get fancy and make the content of the second file a checksum of the first file. Then you could verify the first file. (You don't have the problem with the second file because you just wait until file size = checksum size).
And of course this only works if you can get the sender to send a second file.
I am currently trying to retrieve a file from an FTP-Server in order to make it accessible for the user to download. ftp_get() writes it to a path on the local machine, yes, but what I want is that it also shows up in the download history and counts as "normal" download from the internet but I didn't figure out how to do this yet. I also tried to link directly to the file in PHP with header("Location: ftp://username:password#ftp.server.com/myfile.file") but this was resulting in the browser showing the files contents (which I didn't want). Did I miss any header-Parameters ? Or is there a completely different way to do this ?
You won't be able to "redirect" a user to a file so he can download it using FTP. This is a HTTP-thing. Browsers provides FTP features and make it look like HTTP but, in fact, those are different stuff.
If this file is only accessible through FTP and it is on a remote server, the only way I can imagine so you cand 'redirect' this download to the user is:
Download the file from the FTP to your application server through FTP in PHP;
Send it to the user using PHP and appropriate file headers, something like this: https://stackoverflow.com/a/7263943/2802720
Hope it helps.
I've looked through the site and can't find an answer to my question. I'm trying to make a winrar file (which is 1GB) downloadable from my server and whenever I try, it gives me a winrar file with the same name that is only like 9kb. Here's what I have for the headers. I'm really new to downloadable content so, don't make fun of me. :D
header('Content-Disposition:attachment; filename="java.rar" ');
I'm assuming that I need more. hahaha!
I keep seeing people use header('Content-type: application/pdf'); above their disposition. Does this support rar format, or do I need to use it as zip?
Probably your script is timing out and only a small part from 1GB file is being sent. You may try increasing time limit but IMO for such a big file you'll have to link directly to make it downloadable.
If you want to count file downloads you may link to a php script which will increase the counter and redirect browser directly to the file afterwards.
How to use PHP or any other language to read an uploading-file to allow download of the uploading-file while it is uploading?
Example sites that does this are:
http://www.filesovermiles.com/
http://host03.pipebytes.com/
Use this: http://www.php.net/manual/en/apc.configuration.php#ini.apc.rfc1867
In the array the file name is included as temp_filename - so you can pass that to your other program, which can read from the file and stream it live. The array also includes a file size so that program can make sure not to try to read beyond the end of the file.
I don't think this is possible in PHP because PHP takes care of receiving the download and only hands over control when it has the complete file. When writing CGI programs or Java servlets you read the upload from the socket so you are in control while receiving the file and you can administer if it is still uploading and how much has been received so another process could read this data and start sending what is already there.
One of the site's you've given as an example is just downloading a file from an URL or from the client computer, stores it temporarily and assigns a code to that file to make it identifiable.
After uploading, any other user who has the code can then download that file again.
This is more a question how you operate a server system then writing the code.
You can download files to the local system by making use of file_get_contents and file_put_contents.
If you want to stream file-data from the server to the browser, you can make use of readfile PHP Manual.