Actually, the full error is:
Unable to launch the requested CGI program:
/www/cgi-bin/user_settings.py: Exec format error
The cgi script is:
#-*- coding: utf-8 -*-
import cgi
print "Content-type: text/html; charset=UTF-8"
print
form = cgi.FieldStorage()
print "Hello"
The form element:
<form method="POST" action="/cgi-bin/user_settings.py">
An ls -al shows:
root@ericyun:/www/cgi-bin# ls -al
-rwxr-xr-x 1 root root 216 May 9 21:49 user_settings.py
And in the web server config, I added:
list interpreter ".py=/usr/bin/python"
I've read through some of the other posts that ask about python CGI scripts and I think I got it all covered.
Thanks for any and all help. 
comment out
nano /etc/config/uhttpd
#list interpreter ".py=/usr/bin/python"
/etc/init.d/uhttpd restart
nano /www/cgi-bin/myfirst.py
#!/usr/bin/python
import cgi
import os
print "Content-type: text/html"
print
print """
<html>
<head><title>Sample CGI Script</title></head>
<body>
<h3> Sample CGI Script </h3>
"""
client = cgi.escape(os.environ["REMOTE_ADDR"])
print ('your IP Address is: ' + client + '
')
arguments = cgi.FieldStorage()
for key in arguments.keys():
print key + '='
print arguments[key].value + '
'
print """
</body>
</html>
"""
chmod 755 /www/cgi-bin/myfirst.py
browser http://192.168.0.102/cgi-bin/myfirst.py?x=1&y=2
your IP Address is: 192.168.0.100
y= 2
x= 1
EricBrian:
::::SNIP::::
I've read through some of the other posts that ask about python CGI scripts and I think I got it all covered.
Thanks for any and all help. 
@EricBrian,
the first line should be code, blank, a blank comment, or have a shebang.
Google: unix shebang
So that means your first line should be:
#!/path/to/python
The line you have is to inform the interpreter that you will be using utf-8 source-code encoding.
PEP 0263 -- Defining Python Source Code Encodings
Lastly, the code by SonnyYu has a slight error. He forgot to include the first hash (#).
Jesse
I think sonny also has a typo in the nano command, I don't think the colon should be there.
Thank you @SonnyYu and @Jesse for this info. My script and the script by Sonny now produce this error:
The CGI process did not produce any response
I can get to the Arduino Web Panel without problems.
Thank you too @ShapeShifter. I use 'vi' anyhow and not nano so I knew what to do. 
EricBrian:
Thank you @SonnyYu and @Jesse for this info. My script and the script by Sonny now produce this error:
The CGI process did not produce any response
I can get to the Arduino Web Panel with no problems.
Thank you too @ShapeShifter. I use 'vi' anyhow and not nano so I knew what to do. 
This should help:
Web Server Configuration (uHTTPd)
http://wiki.openwrt.org/doc/uci/uhttpd
Happy Mom's Day
Jesse
jessemonroy650:
This should help:
Web Server Configuration (uHTTPd)
Web Server Configuration (uHTTPd) [Old OpenWrt Wiki]
Thank you for this Jesse. But I fail to see how that would help me. It appears that the web server works with the exception of my custom cgi scripts.
nano /www/cgi-bin/test.cgi
#!/usr/bin/python
print "Content-type: text/html"
print
print """
<html>
<head><title>Sample CGI Script</title></head>
<body>
<h3> Sample CGI Script </h3>
"""
print """
</body>
</html>
"""
chmod 755 /www/cgi-bin/test.cgi
Run it:
/www/cgi-bin/test.cgi
Content-type: text/html
<html>
<head><title>Sample CGI Script</title></head>
<body>
<h3> Sample CGI Script </h3>
</body>
</html>
/etc/init.d/uhttpd restart
View it at http://192.168.0.102/cgi-bin/test.cgi
Thank you Sunny for the response.
The cgi script in this latest post from you worked great. However, your 1st script and my script still don't work. 
Add back missing code block one by one:
import cgi
import os
...
client = cgi.escape(os.environ["REMOTE_ADDR"])
print ('your IP Address is: ' + client + '
')
Test http://192.168.0.102/cgi-bin/test.cgi, next:
...
arguments = cgi.FieldStorage()
for key in arguments.keys():
print key + '='
print arguments[key].value + '
'
...
browser http://192.168.0.102/cgi-bin/test.cgi?x=1&y=2
Sonny,
I reflashed the Yun and now things seem to work.
Thank you for your help! 
EricBrian:
Thank you for this Jesse. But I fail to see how that would help me. It appears that the web server works with the exception of my custom cgi scripts.
@EricBrian,
reading the instructions is proven method of solving issues and bugs.
Jesse