CGI newbie!
Nearly there but not quite as you discovered 
The problem is that the web server doesn't have a handler for Python programs so it just passes the file to the browser with the results you've seen. The quick fix is to alter your code as follows to run the Python interpreter in a shell:
Change the "action" in your index.html file to read
<form method=POST action="cgi-bin/cgi101.cgi">
Rename your existing cgi101.py file to cgi101.cgi
Set the permissions of your index.html file to 640 (probably the default set by your FTP program).
Set the permissions of cgi101.cgi to 700.
Browse to index.html, fill in the text box and click "submit" and … I get "Hello David!"
David
The problem is that the web server doesn't have a handler for Python programs so it just passes the file to the browser with the results you've seen. The quick fix is to alter your code as follows to run the Python interpreter in a shell:
Change the "action" in your index.html file to read
<form method=POST action="cgi-bin/cgi101.cgi">
Rename your existing cgi101.py file to cgi101.cgi
Set the permissions of your index.html file to 640 (probably the default set by your FTP program).
Set the permissions of cgi101.cgi to 700.
Browse to index.html, fill in the text box and click "submit" and … I get "Hello David!"
David
Thanks for that - it worked.
But I don't quite understand what is happening. Is the cgi script being downloaded to my computer, run there and the result sent back to the web server? But then that would mean it would fail for a browser running on a machine without Python installed.
Or is it that the server does have a python interpreter, but doesn't know that it is supposed to execute the script unless its name has a .cgi extension? Then the server machine itself reads the #!/usr/bin/python line. That sounds as if it must be the correct explanation, but I'd be glad if you could confirm that.
David
But I don't quite understand what is happening. Is the cgi script being downloaded to my computer, run there and the result sent back to the web server? But then that would mean it would fail for a browser running on a machine without Python installed.
Or is it that the server does have a python interpreter, but doesn't know that it is supposed to execute the script unless its name has a .cgi extension? Then the server machine itself reads the #!/usr/bin/python line. That sounds as if it must be the correct explanation, but I'd be glad if you could confirm that.
David
The explanation in your last paragraph applies.
The web server knows how to handle .php (PHP), .pl (Perl) and .cgi (shell script) files. What we do here is tell the shell to use the file given on the shebang line (#!/usr/bin/python) to interpret the script. This is the Python interpreter which runs on the server and interprets remaining lines in the file. Output is served to your browser starting with headers (Content-type: text/html followed by an empty line created by \n (and a second \n the print command creates)) to tell your browser what to expect. Since it is text/html your browser displays it on your screen.
I assume you put the Python script file in the /cgi-bin directory because the book tells you to. On ccgi that isn't necessary, though clearly it must be where the form action option points. Also the .htaccess files you mentioned don't serve any purpose and can be removed.
David
The web server knows how to handle .php (PHP), .pl (Perl) and .cgi (shell script) files. What we do here is tell the shell to use the file given on the shebang line (#!/usr/bin/python) to interpret the script. This is the Python interpreter which runs on the server and interprets remaining lines in the file. Output is served to your browser starting with headers (Content-type: text/html followed by an empty line created by \n (and a second \n the print command creates)) to tell your browser what to expect. Since it is text/html your browser displays it on your screen.
I assume you put the Python script file in the /cgi-bin directory because the book tells you to. On ccgi that isn't necessary, though clearly it must be where the form action option points. Also the .htaccess files you mentioned don't serve any purpose and can be removed.
David
Thanks for all your help.
I may be back when I get to the next stage...
David
I may be back when I get to the next stage...
David