I found a puzzling behavior using perl cgi for which -- I guess -- there is a perfectly valid explanation but I couldn't find one.
There is this question on stackoverflow, but what it describes seems to fail for me.
The situation:
I have two perl cgi scripts. One of them (let's say script.pl) can produce a website standalone, but also has a parameter let's call it BARE so that it will simply spit out non-formatted information.
#!/usr/bin/perl
use strict;
use CGI;
my $cgi = new CGI;
unless ( defined $cgi->param('BARE') ) {
print $cgi->header, $cgi->start_html,$cgi->h1('Hello World'), $cgi->end_html;
} else {
print "Bare";
}
Now I am trying to call this script with its 'BARE' parameter set as local script (as they are in the same directory) from another script (let's call it call_my_script.pl).
#!/usr/bin/perl
use strict;
use CGI;
my $cgi = new CGI;
my $result = qx(./script.pl "BARE=1");
print $cgi->header,$cgi->start_html,$result,$cgi->end_html;
When running this script from the command line, I get:
> ./call_my_script.pl
Content-Type: text/html; charset=ISO-8859-1
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">
<head>
<title>Untitled Document</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
</head>
<body>
Bare
</body>
</html>
When instead I call the same script via browser it returns
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US"><head><title>Untitled Document</title>
</head><body>Content-Type: text/html; charset=ISO-8859-1
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US"><head><title>Untitled Document</title>
</head><body><h1>Hello World</h1></body></html></body></html>
So despite the fact that I am calling the first script locally using qx and I am passing the parameter to get bare formatting, this does not get respected when calling things via browser.
I am probably overlooking something obvious, but I'd be grateful to understand what it is.
A CGI program normally expects to fetch the parameter values from the environment variable
QUERY_STRING. Passing parameter values on the command line is a debugging facility, and works only when the program is run from the command promptYou could try something like this