#!/usr/bin/perl -Tw #++ # Based on # # Source code to accompany # _Official Guide to Programming with CGI.pm: The Standard for Building Web Scripts_ # by Lincoln Stein # (c) 1998 by Lincoln Stein # Published by John Wiley & Sons, Inc. (ISBN 0-471-24744-8) #-- use diagnostics; use CGI qw(:standard); use CGI::Carp 'fatalsToBrowser'; use strict; $| = 1; html_start(); if (param) { print_results(); } else { print_form(); } html_end(); # - - - - - subroutines - - - - - - sub print_results { my $length; my $file = param('upload'); if (!$file) { print "

No file uploaded.

"; return; } print '

Proof that we have the file

'; print '

File name: $file
File MIME type: $type; unknown
File length: $length

'; print '

In the CGI perl program

'; print '

File name: $file = param("upload")
File MIME type: uploadInfo($file)->{"Content-Type"}; uploadInfo() is part of CGI.pm
File length: using while (<$file>) for example; the key is to use the filename in a file context

'; print '

What else was passed in the header

'; print '

$_: $$fileinfo{$_}

'; $\="\n"; print '

In the CGI program

'; print '

';
    print '# uploadInfo returns a reference to a hash';
    print '# $fileinfo is the reference to that hash';
    print 'my $fileinfo = uploadInfo($file);';
    print '
';

    print 'print "  <dl>";';
    print 'foreach (keys %{$fileinfo}) {';
    print '   # $$fileinfo is that hash, not a reference to it';
    print '   print "    <dt>$_</dt> <dd>$$fileinfo{$_}</dd>";';
    print '}';
    print 'print "  </dl>";';
    print '

'; print '

On the Server...

'; print '

';
    print 'print "<p>"';
    print 'print " On the server, the file is stored in "';
    print 'print " `<kbd>tmpFileName($file);</kbd>\'?"';
    print 'print "<p>"';
    print '

'; print '

On the server, the file is stored in `', tmpFileName($file), '\'?

'; # open(FILE, tmpFileName($file)); # print '

+++';
   # while() {print};
   # print '---

'; # printf "

file permissions are %04o

\n", ((stat tmpFileName($file))[2]) & 07777; }# print_results() sub html_start { print header; print << 'EOHTML'; File Upload Form Example for Dal CS 4173 : Web-centric Computing

Web-centric Computing

Example Code

Forms: File Upload

EOHTML ; }# html_start() sub print_form { print << 'EOHTML'

 <form method="post"  
       enctype="multipart/form-data"
       accept="text/plain"
       action="http://users.cs.dal.ca/~jamie/cgi-bin/4173/form/upload.cgi">
  <p>
   <input type="file"   name="upload" size="60" />
   <br />
   <input type="submit" name="submit" value="upload file" />
  </p>
 </form>

Note that

The enctype attribute must be multipart/form-data to tell the server that there are multiple sections in the input.
- Normally there is just one part.
- With file upload, the file is sent in a second section.
The form must be submitted with method="post" since there are two sections to the input, and method="get" can only do one.
The accept attribute may be used to limit which types of files can be sent.
- Not all browsers bother to check this.

EOHTML ; }# print_form() sub html_end { print << 'EOHTML'

`http://www.cs.dal.ca/~jamie/cgi-bin/4173/form/upload.cgi`

Version:: 30 October 2001
Author:: J. Blustein <jamie@cs.dal.ca>

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EOHTML ; }# html_end()