如何使用Mason来实现文件上传

The basic HTML for an upload form looks like:

<form action="..." method="post" enctype="multipart/form-data"> 
Upload new file: <input name="userfile" type="file" class="button"> 
<input type="submit" value="Upload">

The way you handle the submission depends on which args method you chose for the ApacheHandler class.
Under the 'CGI' method (default for 1.0x), you can use the $m->cgi_object method to retrieve a CGI.pm object which can be used to retrieve the uploaded file. Here is an example using the 'CGI' method:

<%init> 
my $query = $m->cgi_object; # get a filehandle for the uploaded file 
my $fh = $query->upload('userfile'); # print out the contents of the uploaded file 
while (<$fh>) { print; } 
close($fh); 
</%init>

Please see the CGI.pm documentation for more details.
Under the 'mod_perl' method (default for 1.1x), the request object available as $r in your components will be an object in the Apache::Request class (as opposed to the Apache class). This object is capable of returning Apache::Upload objects for parameters which were file uploads. Please see the Apache::Request documentation for more details. Here is an example using the 'mod_perl' method:

<%init> 
# NOTE: If you are using libapreq2 + mod_perl2 + Apache 2, 
# you will need to uncomment the following line: # use Apache::Upload; 

# you can store the file's contents in a scalar my $file_contents; # create an Apache::Upload object 
my $upload = $r->upload; # get a filehandle for the uploaded file 
my $upload_fh = $upload->fh; 
while(<$upload_fh>) { # loop through the file and copy each line to $file_contents $file_contents .= $_; } 
close($upload_fh); 
</%init>

For more information on how to manually set the args method, see the ApacheHandler documentation.
If you are using CGI.pm, there are some configuration issues to be aware of. CGI.pm needs a tmp directory, and you probably want to be able to specify what that directory is.
Try doing this in your httpd.conf or handler.pl:

<Perl> 
use CGI qw(-private_tempfiles); 
</Perl>

You must do this before you load either the HTML::Mason or HTML::Mason::ApacheHandler modules.
That may change which directories CGI tries to use.
You could also try

$CGI::TempFile::TMPDIRECTORY = '/tmp';

during startup, either in your httpd.conf or handler.pl
The root of the problem is probably that the temp directory is being chosen when the module loads uring server startup while its still root. It sees it can write to /usr/tmp and is happy. Then when actually running as nobody it dies.
I bet Lincoln would welcome a patch (hint, hint). One solution would be to check if you're running under mod_perl and you're root. If so, then check Apache->server->uid and see if that id can write to the temp directory too.

两种方法中，当然使用mod_perl为佳，cgi的实现方式还需要写缓存文件，如果磁盘空间不足，则会出现无法上传的情况。

一个使用的实例：http://passport.maxthon.cn/new/myprofile/avatar.html

引自：http://www.masonhq.com/?FAQ:HTTPAndHTML#h-how_can_i_handle_file_uploads_under_mason