Writing Your Own Form Handling Scripts (Perl CGI), Part III
Todays' article is the third of four installments. Here is a table of contents for the entire series:
- How to put information from the form into the script.
- How to store the form information in a database file on your server -- in any plain text format, including tab- and comma-delimited formats that can be imported into Excel and other spreadsheet and database programs.
- How to send the form information to yourself in an email -- formatted however you please, including HTML.
- The example form and the script.
- The email template.
- Sending the email.
- The script up to this point.
- How to personalize the "thank you"/confirmation page for your form user.
If you haven't read Parts I and II of this tutorial, do so now. They are linked from the Willmaster Library index.
III. How to send the form information to yourself in an email -- formatted however you please, including HTML.
a. The example form and the script.
Retrieve the example form and script from the "Writing Your Own Form Handling Scripts, Part II" linked at the Willmaster Library index.
The script, with today's modifications incorporated, is also printed at the end of this article.
b. The email template.
The first thing to do is create an email template file. The template will be the outgoing email's format with placeholders where the script will insert form information before sending the email.
Placeholders for email templates are the same as for database templates, form field names enclosed with double square brackets. Here is an example email template:
From: "[[username]]" <[[email]]> To: "Your Name" <email@domain.com> Cc: "Another Name" <another@domain.com> Bcc: a@domain.com, b@domain.com, c@domain.com Subject: [[Subject]] The form has been submitted with the following information: Name: [[username]] Email: [[email]] Gender: [[gender]] Favorite Color: [[favorite color]] Color List: [[c2]] Message: [[message]]
A few notes about the above email template:
- The first lines of the template are the header
lines of the outgoing email.
- A minimum header is the "To:" line. The rest in
the example are optional.
- The sequence of the header lines doesn't matter.
- If you want to send HTML email, add the following two lines to the header:
Mime-Version: 1.0 Content-Type: text/html; charset="iso-8859-1"
- There must be a one blank line between the header lines and the email body, and it must be the first blank line in the file.
The email body can have placeholders for any or all of the form information, or even none if you just want to send a "thank you" email (in which case the "To:" header line would have the form user's email address).
c. Sending the email.
Near the top of the script, insert these two lines:
my $EmailTemplateFile = 'template.txt'; my $Mailer = '/sbin/sendmail -t';
The $EmailTemplateFile variable holds the file name of the email template you created above. The file should be uploaded into the same directory as the script.
The $Mailer line holds the location of your sendmail or qmail. If sendmail, include the -t flag. Either sendmail and qmail are almost always found on UNIX/Linux servers. The emailing subroutine below will send email only if one of those two are present on the server.
Put this emailing subroutine at the bottom of your script:
sub SendEmail
{
open R,$EmailTemplateFile;
my $email = join '',<R>;
close R;
for(keys %In) { $email =~ s/\[\[$_\]\]/$In{$_}/sig; }
$email =~ s/\[\[.*?\]\]//sig;
open MAIL,"|$Mailer";
print MAIL $email;
close MAIL;
} # sub SendEmail
The first three lines retrieve your email template. The next two lines replace the placeholders with form information. And the last three lines send the email.
To use the SendEmail subroutine, your statement would be:
&SendEmail;
Put the statement immediately below the &UpdateDatabase; statement mentioned in the section II.
d. The script up to this point.
Here is the form handling script up to this point:
#!/usr/bin/perl
# By [your name here]
use strict;
my $AuthorizedDomain = 'mydomain.com';
my $DBtemplate = "[[username]]\t[[email]]\t[[message]]\n";
my $DatabaseFile = 'data.txt';
my $EmailTemplateFile = 'template.txt';
my $Mailer = '/sbin/sendmail -t';
my %In = ();
my $FormDomain = lc $ENV{HTTP_REFERER};
$FormDomain =~ s!^https?://(?:www\.)?(.*?)(?:/.*)$!$1!;
unless($FormDomain eq lc $AuthorizedDomain)
{ ErrorHTML('Unauthorized access.'); }
unless(ParsePost())
{ ErrorHTML('Unauthorized access.'); }
unless($In{email})
{ ErrorHTML('An email address is required.'); }
unless(ValidEmail($In{email}))
{ ErrorHTML('Sorry, invalid email address format.'); }
if(length($In{message}) > 250)
{ $In{message} = substr($In{message},0,250); }
&UpdateDatabase;
&SendEmail;
ErrorHTML('Script paused here.'); # temporary line
Exit();
sub ParsePost
{
return 0 unless $ENV{REQUEST_METHOD} =~ /POST/i;
my $buffer;
read(STDIN,$buffer,$ENV{CONTENT_LENGTH});
my @p = split(/&/,$buffer);
foreach(@p)
{
$_ =~ tr/+/ /;
my ($n,$v) = split(/=/,$_,2);
$n =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
$v =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
$v =~ s/(\<.*?)(embed|object|script|applet)(.*?\>)/$1$3/gis;
if($In{$n}) { $In{$n} .= "\t$v"; }
else { $In{$n} = $v; }
}
return 1;
} # sub ParsePost
sub ValidEmail
{
if($_[0]=~/([\.\-\_]{2,})|(@[\.\-\_])|([\.\-\_]@)|(\A\.)/)
{ return 0; }
if($_[0]=~/^[\w\.\-\_]+\@\[?[\w\.\-\_]+\.([\w\.\-\_]{2,3}|[0-9])\]?$/)
{ return 1; }
return 0;
} # sub ValidEmail
sub ErrorHTML
{
my $s = join("\n<li>",@_);
print "Content-type: text/html\n\n";
print <<HTML;
<html><body bgcolor="white">
<blockquote><blockquote>
<h4>Message:</h4>
<ul>
<li>$s
</ul>
</blockquote></blockquote>
</body></html>
HTML
Exit();
} # sub ErrorHTML
sub Exit { exit; }
sub MakeOneLine
{
my $s = shift;
my $replacement = '<br>';
if($s =~ /\n/) { $s =~ s/\r//gs; }
else { $s =~ s/\r/\n/gs; }
$s =~ s/\n/$replacement/gs;
return $s;
} # sub MakeOneLine
sub ConvertTabValueSeparaters
{
my $s = shift;
my $replacement = ' -- ';
$s =~ s/\t/$replacement/gs;
return $s;
} # sub ConvertTabValueSeparaters
sub GetFormattedDate
{
my @Weekday = qw(
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday);
my @Month = qw(
January
February
March
April
May
June
July
August
September
October
November
December);
my ($sc,$mn,$hr,$mday,$mon,$yr,$wday,$yday,$dst) = localtime;
$yr += 1900;
return "$Weekday[$wday], $Month[$mon] $mday, $yr";
} # sub GetFormattedDate
sub GetFormattedTime
{
my ($sc,$mn,$hr,$mday,$mon,$yr,$wday,$yday,$dst) = localtime;
my $s = '';
$s .= $hr < 10 ? "0${hr}:" : "${hr}:";
$s .= $mn < 10 ? "0${mn}:" : "${mn}:";
$s .= $sc < 10 ? "0${sc}" : $sc;
return $s;
} # sub GetFormattedTime
sub UpdateDatabase
{
my $t_message = $In{message};
my $t_c2 = $In{c2};
$In{message} = MakeOneLine($In{message});
$In{c2} = ConvertTabValueSeparaters($In{c2});
$In{Date} = &GetFormattedDate;
$In{Time} = &GetFormattedTime;
for(keys %In) { $DBtemplate =~ s/\[\[$_\]\]/$In{$_}/i; }
$DBtemplate =~ s/\[\[.*?\]\]//i;
if(-e $DatabaseFile) { open W,">>$DatabaseFile"; }
else { open W,">$DatabaseFile"; }
print W $DBtemplate;
close W;
$In{c2} = $t_c2;
$In{message} = $t_message;
} # sub UpdateDatabase
sub SendEmail
{
open R,$EmailTemplateFile;
my $email = join '',<R>;
close R;
for(keys %In) { $email =~ s/\[\[$_\]\]/$In{$_}/sig; }
$email =~ s/\[\[.*?\]\]//sig;
open MAIL,"|$Mailer";
print MAIL $email;
close MAIL;
} # sub SendEmail
The "Script paused here." message in the above code will be removed when the script is completed.
Part IV of this series shows you how to take the information in the %In variable and create custom "thank you" pages.
See you then :)
Will Bontrager
