Typically, monks will warn new programmers that they must use strict. This pragma is useful, but if you just don't understand programming, it's a false sense of security. Today, I'm working on some code another (ex) employee wrote. The code allows a user to fill out a form, use an attachment, and email the data to one of our users. How many problems can you find? Here's a blindingly obvious hint on one of them: the programmer never told the admin about the directory he was saving files to.

my $outputFile;
if( $_file_name !~ /^(\s*)$/ ) {
    use constant BUFFER_SIZE   => 16_384;    # Amount of upload file t
+o read at one time
    use constant MAX_FILE_SIZE => 3_145_728; # This is the filesize up
+load limit

    $CGI::DISABLE_UPLOADS      = 0;          # Temporarily reenable up
+loads
    $CGI::POST_MAX             = MAX_FILE_SIZE;
    
    # Path and Filename
    my $file_name = $_file_name;    
    my $file_type = $query->uploadInfo($file_name)->{'Content-Type'};
    
    my $basename = basename($file_name);
    
    if( $file_type =~ /octet-stream/ ) { 
        $errors{ 'file_type' } = ["","","Unrecognize your submitted re
+sume file format."];
        goto Print;
    }    
    $outputFile = $UPLOAD_RESUME_DIRECTORY . $basename ;
    my $buffer = "";    
    open(OUTPUT,">>$outputFile");
    my @stats;
    
    # Need binmode or Win32 systems will convert end-of-line chars
    binmode OUTPUT;
    {
        no strict 'refs';                     
        READ_FILE: while ( read( $file_name, $buffer, BUFFER_SIZE ) ) 
+{
            print OUTPUT $buffer;
            @stats = stat $outputFile;    
            last READ_FILE if ( $stats[7] > MAX_FILE_SIZE )
        }
    }
    close(OUTPUT);
    
    #check the file size
    if ( $stats[7] > MAX_FILE_SIZE || %errors ) {
        $errors{'file_size'} = ["","","Your submitted file's size is o
+ver 3MB."];
        unlink $outputFile;

[download]

I'll post my observations later. Be careful, there are some subtle bugs here.

Cheers,
Ovid

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In reply to strict isn't everything by Ovid

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