Site5 Q&A » Hello World for Python

Hello World for Python

In: Python Asked By: efreed [2

] Tags: cgi, python

I’ve made a hello.py file in the cgi-bin directory. The contents of the file are:

#!/usr/bin/env python

print(“Content-Type: text/plain”)
print(“”)
print(“Hello World!”)

Then in the browser I open /cgi-bin/hello.py and get a 500 server error.

I’ve tried with/without parenthesis on the print lines.

I’ve tried using the web file manager to set file permissions to 777.

Where do I get more information about this error?

Should this work, or what should I be doing?

4 Answers Answer this Question Now

Jan 28, 2014

Answer #1

Hello! Try setting the first line to the following:

#!/usr/bin/python

Then set the permissions to 755 rather than 777, and it should work normally for you.

Answered By: jdavey [359

]

Answer #2

All I needed was the permissions at 755, with that even the generic #!/usr/bin/env python worked. I had no idea I could break it by granting too many permissions.

Thank you much!!

Answered By: efreed [2

]

Answer #3

You’re very welcome! Glad it worked out for you 🙂

Answered By: jdavey [359

]

Answer #4

Here are a few notes on things that can cause Server Error 500:

—
Permissions:

If you use chmod 777, 757 or 775 it causes the error.
See these links:
http://kb.site5.com/errors/error-500-internal-server-error/
http://kb.site5.com/ftp/chmod-overview/

—
Line endings:

Lines in your python file must use Unix line endings \n (0x0a).
Windows saves text files with a \r\n (0x0d 0x0a).
If you save in MS-Dos format from a windows editor you will have the wrong line endings.
To see if a file has the wrong line endings you can pipe it through xxd:
xxd test.py

You can fix the line endings by one of the methods below:
From Windows:
Wordpad: Save in non-MS-Dos format. Save As… | Save as type: Text Document (instead of Text Document – MS-DOS Format)
or
Notepad++: open the file then Edit | EOL Conversion | Unix/OSX Format

From Linux:
dos2unix test.py
or
vi test.py then (esc) :set fileformat=unix

—
The Content Line:

You need a line feed after the content line:
print (“Content-type: text/html\n”)
or
print (“Content-type: text/html”)
print (“”)

—
Python Syntax:

If you change your python interpreter to /usr/local/bin/python3.0 then scripts written in 2.x may fail (for example 3.x requires that print statements be in parentheses, etc.)

—
Mics.:

Be sure to check your error log to see what is causing the 500
http://kb.site5.com/control/siteadmin/siteadmin-error-log/

Check your script for syntax errors by running it in the shell: python test.py

Experiment with:
import cgitb
cgitb.enable()

—
Notice we specified the shell like this:
#!/usr/local/bin/python2.6
You can look and see what you have available like this:
Login to Site5 backstage
Site Admin to your site
Programming Center | Python
(You can also ls /usr/bin and /usr/local/bin to see what pythons are installed)

Answered By: matmcnic [2

]

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