http://qs1969.pair.com?node_id=502351

JaredF has asked for the wisdom of the Perl Monks concerning the following question:

I'm having a frustrating time passing a single parameter between two perl .cgi programs (cgi1.cgi & cgi2.cgi). In particular, perl complains like this: Can't call method "param" on an undefined value at C:\Program Files\OptiPerl\Webroot\cgi-bin\cgi2.cgi line 5.
What am I ignorant of (this time)?
Jared 
##############CGI1.CGI###############
#!/usr/local/bin/perl
use CGI qw(:all);
print header;
print "now in cgi1.cgi<BR>";
print q(<A HREF="./cgi2.cgi?i=99">go to cgi2</A>);

##############CGI2.CGI###############
#!/usr/local/bin/perl
use CGI qw(:all);
print header;
print "in cgi2.cgi<BR>";
$i = $query->param('i');
print $i;

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Re: How to pass a parameter between cgi's?
by dragonchild (Archbishop) on Oct 24, 2005 at 00:25 UTC
    In CGI2.CGI, where are you defining $query? It looks to me as if you cut'n'pasted some code from someone else without a full understanding of what it's doing.

    Try either of the following approaches: 

    • #!/usr/local/bin/perl
use CGI qw(:all);
print header;
print "in cgi2.cgi<BR>";
$i = param('i');
print $i;

      [download]
    • #!/usr/local/bin/perl
use CGI;
$query = CGI->new;
print $query->header;
print "in cgi2.cgi<BR>";
$i = $query->param('i');
print $i;

      [download]

    Update: $CGI -> CGI in the second code example.

    My criteria for good software:
    1. Does it work?
    2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?
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[d/l]
[select]
      Dragonchild --
      Code sample #1 works like a charm. Thank you.
      In response to your question -- "In CGI2.CGI, where are you defining $query." -- the answer is: Nowhere in the example, but down below in the actual source code. My mistake. My grasp of OO perl and of CGI are, um, weak enough to cause trouble. Thanks for getting me out of it to complete a rather long piece of code.
      -- Jared
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