Require fields over several cgi scripts

I have several web form scripts, each one calling the next one in sequence. I need to make some variables into required fields such as:

print_error("You must enter your email address") unless $email;

For example, I would need to make "Email" a required field in the first form.

I am using hidden fields in the "here-doc" code to carry the values over to subsequent forms but this code doesn't work here.  What can I do? Your help would be greatly appreciated.

I am a novice so a easy-to-understand answer is necessary :-)

######################### FIRST SCRIPT #######################

#!/usr/bin/perl
use strict;
use CGI;
use CGI::Carp qw(fatalsToBrowser);

my $q = new CGI;


print $q->header;
print <<HTMLCODE;
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Test</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<body bgcolor="#FFFFFF" background="" text="#000000" link="#000000" vlink="#000000" alink="#000000">
<FORM ACTION="http://demo.com/cgi-bin/test/form2.cgi" METHOD="POST">


<TABLE>
 
  <TR>
    <TD>Name: <INPUT name=name></TD></TR>
  <TR>
    <TD>Email: <INPUT name=email></TD></TR>
  <TR>
    <TD><INPUT type=submit value=Submit>
  <INPUT type=reset value=Reset></TD></TR></TABLE></P>
</BODY>
</HTML>


HTMLCODE

sub print_error {
        my $message = shift;

        print $q->header;

        print <<ERRORCODE;

<html>
<head><title>$message</title></head>
<body>

<p align="center"><font color="#000000" face="Arial"><big><strong>Processing Error</strong></big></font></p>

<p align="left"><font face="Arial" color="#000080"><strong>$message</strong></font></p>

<p align="left"><font face="Arial" color="#000080"><strong>Please click your browser's Back button and try again.</strong></font></p>


</body>
</html>

ERRORCODE

        exit;
}

############################## SECOND SCRIPT #####################

#!/usr/bin/perl
use strict;
use CGI;
use CGI::Carp qw(fatalsToBrowser);

my $q = new CGI;
my $name = $q->escapeHTML($q->param('name'));
my $email = $q->escapeHTML($q->param('email'));


print $q->header;
print <<HTMLCODE;
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Test</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<body bgcolor="#FFFFFF" background="" text="#000000" link="#000000" vlink="#000000" alink="#000000">
<FORM ACTION="http://demo.com/cgi-bin/test/form3.cgi" METHOD="POST">
<input type="hidden" name="name" value="$name" />
<input type="hidden" name="email" value="$email" />


<TABLE>
 
  <TR>
    <TD>Age: <INPUT name=age></TD></TR>
  <TR>
    <TD>Country: <INPUT name=country></TD></TR>
  <TR>
    <TD><INPUT type=submit value=Submit>
  <INPUT type=reset value=Reset></TD></TR></TABLE></P>
</BODY>
</HTML>


HTMLCODE

sub print_error {
        my $message = shift;

        print $q->header;

        print <<ERRORCODE;

<html>
<head><title>$message</title></head>
<body>

<p align="center"><font color="#000000" face="Arial"><big><strong>Processing Error</strong></big></font></p>

<p align="left"><font face="Arial" color="#000080"><strong>$message</strong></font></p>

<p align="left"><font face="Arial" color="#000080"><strong>Please click your browser's Back button and try again.</strong></font></p>


</body>
</html>

ERRORCODE

        exit;
}

rincewind666Asked:
Who is Participating?
 
ahoffmannCommented:
in your 2'nd script add something like (after getting $email):

if ("$emal" ~= /^\s*$/) {
  print $q->header;
  print $q->redirect('http://demo.com/form1-page.html');
  exit(0);
}
0
 
rincewind666Author Commented:
I am getting the following error:

Software error:
syntax error at form2.cgi line 39, near ""$email" ~"
syntax error at form2.cgi line 43, near "}"
Execution of form2.cgi aborted due to compilation errors.

This is the amended script:

#!/usr/bin/perl
use strict;
use CGI;
use CGI::Carp qw(fatalsToBrowser);

my $q = new CGI;
my $name = $q->escapeHTML($q->param('name'));
my $email = $q->escapeHTML($q->param('email'));


print $q->header;
print <<HTMLCODE;
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Test</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<body bgcolor="#FFFFFF" background="" text="#000000" link="#000000" vlink="#000000" alink="#000000">
<FORM ACTION="http://demo.com/cgi-bin/test/form3.cgi" METHOD="POST">
<input type="hidden" name="name" value="$name" />
<input type="hidden" name="email" value="$email" />


<TABLE>
 
  <TR>
    <TD>Age: <INPUT name=age></TD></TR>
  <TR>
    <TD>Country: <INPUT name=country></TD></TR>
  <TR>
    <TD><INPUT type=submit value=Submit>
  <INPUT type=reset value=Reset></TD></TR></TABLE></P>
</BODY>
</HTML>


HTMLCODE

################ AMENDED HERE

if ("$email" ~= /^\s*$/) {
  print $q->header;
  print $q->redirect('http://demo.com/form1-page.html');
  exit(0);
}

###############

sub print_error {
        my $message = shift;

        print $q->header;

        print <<ERRORCODE;

<html>
<head><title>$message</title></head>
<body>

<p align="center"><font color="#000000" face="Arial"><big><strong>Processing Error</strong></big></font></p>

<p align="left"><font face="Arial" color="#000080"><strong>$message</strong></font></p>

<p align="left"><font face="Arial" color="#000080"><strong>Please click your browser's Back button and try again.</strong></font></p>


</body>
</html>

ERRORCODE

        exit;
}

0
 
ozoCommented:
~= should be =~
0
Cloud Class® Course: Amazon Web Services - Basic

Are you thinking about creating an Amazon Web Services account for your business? Not sure where to start? In this course you’ll get an overview of the history of AWS and take a tour of their user interface.

 
ahoffmannCommented:
thanks for correting my typos, ozo
0
 
rincewind666Author Commented:
It is not being redirected. The next form is displayed with this message on the bottom:

Content-Type: text/html; charset=ISO-8859-1 Status: 302 Moved Location: http://demo.com/form1-page.html 
0
 
ahoffmannCommented:
damn, had a lazy day ... sorry.
Please remove in the if
  print $q->header;
0
 
rincewind666Author Commented:
I've changed this to:

if ("$email" =~ /^\s*$/) {
  print $q->redirect('http://demo.com/form1-page.html');
  exit(0);
}

Now the next form is still being displayed with this message on the bottom:
Status: 302 Moved Location: http://demo.com/form1-page.html 
0
 
ahoffmannCommented:
do you have another
  print $q->header;
right before the if?
If so, move it behind the if
0
 
rincewind666Author Commented:
No.  Still getting the same error. Here is the current code:

#!/usr/bin/perl
use strict;
use CGI;
use CGI::Carp qw(fatalsToBrowser);

my $q = new CGI;
my $name = $q->escapeHTML($q->param('name'));
my $email = $q->escapeHTML($q->param('email'));

#print $q->header;
print <<HTMLCODE;
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Test</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<body bgcolor="#FFFFFF" background="" text="#000000" link="#000000" vlink="#000000" alink="#000000">
<FORM ACTION="http://demo.com/cgi-bin/test/form3.cgi" METHOD="POST">
<input type="hidden" name="name" value="$name" />
<input type="hidden" name="email" value="$email" />

<TABLE>
 
  <TR>
    <TD>Age: <INPUT name=age></TD></TR>
  <TR>
    <TD>Country: <INPUT name=country></TD></TR>
  <TR>
    <TD><INPUT type=submit value=Submit>
  <INPUT type=reset value=Reset></TD></TR></TABLE></P>
</BODY>
</HTML>

HTMLCODE

if ("$email" =~ /^\s*$/) {
  print $q->redirect('http://demo.com/form1-page.html');
  exit(0);
}
print $q->header;

sub print_error {
        my $message = shift;

        print $q->header;

        print <<ERRORCODE;

<html>
<head><title>$message</title></head>
<body>

<p align="center"><font color="#0000000" face="Arial"><big><strong>Processing Error</strong></big></font></p>

<p align="left"><font face="Arial" color="#000080"><strong>$message</strong></font></p>

<p align="left"><font face="Arial" color="#000080"><strong>Please click your browser's Back button and try again.</strong></font></p>


</body>
</html>

ERRORCODE

        exit;
}
0
 
ahoffmannCommented:
no, no, please read my comments!

...
   my $email = $q->escapeHTML($q->param('email'));
   if ("$email" =~ /^\s*$/) {
     print $q->redirect('http://demo.com/form1-page.html');
     exit(0);
   }
   print $q->header;
   print <<HTMLCODE;
...

and always exit your cgi with
  exit( 0 );
otherwise you get a server 500 error ..
0
 
TintinCommented:
ahoffman.

Please explain your rationale behind:

and always exit your cgi with
 exit( 0 );

0
 
ahoffmannCommented:
Tintin, the CGI defines that each called cgi must return 0 on success, otherwise the web-server should/must return a server 500 error.
A perl script returns 0 by default, of the last command right before the final return/exit was successful, so it can be omitted.
Writing exit(0) is clean programing, beside you never know what happens on the system ..
0
 
TintinCommented:
A lot of people (myself included) would argue that adding a exit(0) in a Perl (or shell script) for that matter at the end of the script is totally redundant and unless your last command has any error checking, it could mean a misleading result.
0
 
rincewind666Author Commented:
Thanks for your help.  Much appreciated.
0
 
ahoffmannCommented:
it might be redundant, but it's bad, very bad, programming style to leave it all to the interpreter's (perl) implementation
and in case of errors, you don't know what happend.
Think secure ;-)
0
 
TintinCommented:
ahoffman.

I'll agree to disagree on this one.

Here's an example of it giving misleading results:

#!/bin/sh
sdf
exit 0
0
 
ahoffmannCommented:
.. or this one:
#!/bin/sh
/bin/false
exit 0

;-)

rincewind666, hope you got a valuable solution beside some off-topic chat ..
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.