Two things - One, always use binmode() when opening files for reading or writing. This dosen't hurt under Unix, and it's certainly necessary under Windows.

The second, and even more important thing, use CGI; ! CGI.pm will make uploading files to your server as easy as :

        # Copy a binary file to somewhere safe
        open (OUTFILE,">>/usr/local/web/users/feedback");
        binmode OUTFILE;
        while ($bytesread=read($filename,$buffer,1024)) { 
          print OUTFILE $buffer;
        }
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And while we're giving general advice, always check to see if your file gets opened in the first place!

open (OUTFILE,">$file") or die "Couldn't open '$file': $!\n";
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Lincoln Stein describes binmode() in his most meritorious work Network Programming With Perl. He writes:

In text mode, however, the standard I/O library automatically translates LF into CRLF pairs on the way out, and CRLF pairs into LF on the way in. The virtue of this is that it makes text operations on Windows and UNIX Perls look the same—from the programmer's point of view, the DOS text files end in a single \n character, just as they do in UNIX. The problem one runs into is when reading and writing binary files—such as images or indexed databases—and the files become mysteriously corrupted on input or output. This is due to the default line-end translation. Should this happen to you, you should turn off character translation by calling binmode() on the filehandle.

Generally one ought not to run binmode() when one is reading and writing text on Windows and VMS system. But reading between the lines of Stein's advice makes me think that perhaps one ought to turn on binmode only as needed even when running binary files.

When I used to open up DOS binary files in text editors I would often see what looked like meaningful text there. Perhaps "to every thing there is a season" as it says in Ecclesiastes and even binary files should sometimes be run without binmode() in order to handle these meaningful snippets of text in binary files.

Yes, I get the same "between the lines" impression, but that doesn't change the fact that such advice is just wrong.

Always use binmode() when dealing with binary data in files and never use bindmode() when dealing with only text data in files.

If you read a binary file without binmode() in DOS and expect to find the text bits in better shape, then you will be surprised when the binary data contains CTRL-Z and your program refuses to read past that, no matter how much text appears later in the file.

I find particularly unfortunate the "Should this happen to you" bit. "Well, I know it is possible that dealing with binary files w/o binmode() might cause problems but you should really wait to fix such problems until such time as you stumble upon them."

I'm disappointed at how frequently discussions of binmode() say stuff like "Use this if you aren't on Unix and...".

        - tye (but my friends call me "Tye")

Hi, thanks for your help.
I have just tried it that way and still isn't working. I tried printing out $bytesread but it seems to have no value.
I also checked if the filename that gets passed to my code is correct and that's the case. Am I missing something?

AgentM Systems nor Nasca Enterprises nor Bone::Easy nor Macperl is responsible for the comments made by AgentM. Remember, you can build any logical system with NOR.

the code looks alright. but you didn't include the code that gave you the $data filehandle. be sure that $data was retrieved something like so:

my $data = $query->param("uploadfileTagname");
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a common gotcha is opening the uploaded filehandle for read, then trying to write it back out. at least it "got" me....once :-)

I get my $data like this my $data        = $cgi -> param ( 'data' );
Give it to my subroutine like this &receive_upload ( $data );
And receive the value in my subroutine like this my $data = shift;

from perlfaq5...

For passing filehandles to functions, the easiest way is to preface them with a star, as in func(*STDIN). See the section on Passing Filehandles in the perlfaq7 manpage for details.

from perlfaq7...

How can I pass/return a {Function, FileHandle, Array, Hash, Method, Regexp}?
With the exception of regexps, you need to pass references to these objects. See the section on Pass by Reference in the perlsub manpage for this particular question, and the perlref manpage for information on references.

-mark

I'd put my money on this solution. If you didn't specify the correct mime-type when posting the file from the upload form, then there's nothing for the Perl script to accept.