Standard Hello World from a Python CGI Script
well, mostly standard anyways...
This version is a self printing python program that demonstrates how to use python as a CGI script
This documents my experiences using DreamHost as my hosting provider. Your milage may vary
It is very important that Python CGI scripts...
- have '
!#usr/bin/python'
as the first line of the file
this tells the system what interpreter to use / what language it is.
This code, using that command, right now, on this host, is using Python 2.7.18 (default, Jul 1 2022, 12:27:04)
[GCC 9.4.0]
For specific versions of Python here at Dreamhost, you could use one of ...
v2.1.3 -> #!/usr/bin/python2.1
v2.2.1 -> #!/usr/bin/python2.2
v2.3.5 -> #!/usr/bin/python2.3
v2.4.6 -> #!/usr/bin/python2.4
v2.5.2 -> #!/usr/bin/python2.5
v2.7.3 -> #!/usr/bin/python2.7
(noticing a pattern here?)
- end in '
.py'
- print the '
Content-type: text/html\n' header
in the first line if you want to view the output
- mark the file as executable:
'
chmod 755 [filename.py]'
This is a self printing file, full source code follows
Or you could view the source directly
helloworld.txt
#!/usr/bin/python
# for linux
import sys
def main():
print "Content-type: text/html\n"
print "<HTML><TITLE>Hello World from Python</TITLE><body>"
print "Standard <b>Hello World</b> from a Python CGI Script<p />"
print "well, <i>mostly standard</i> anyways...<p/>"
print "This version is a self printing python program that demonstrates how to use python as a CGI script<p/> "
print 'This documents my experiences using <a href="http://dreamhost.com">DreamHost</a> as my hosting provider. <b>Your milage may vary</b><p/>'
print "It is very important that Python CGI scripts..."
print "<ol>"
print "<li>have '<code>!#usr/bin/python</code>' "
print "as the first line of the file<br/>"
print "this tells the system what interpreter to use / what language it is.<br/>"
print "This code, using that command, right now, on this host, is using Python <code>%s</code><br/>" % sys.version
print "For specific versions of Python here at Dreamhost, you could use one of ...<br/>"
print "<strike>v2.1.3 -> <code>#!/usr/bin/python2.1</code></strike><br/>"
print "<strike>v2.2.1 -> <code>#!/usr/bin/python2.2</code></strike><br/>"
print "<strike>v2.3.5 -> <code>#!/usr/bin/python2.3</code></strike><br/>"
print "<strike>v2.4.6 -> <code>#!/usr/bin/python2.4</code></strike><br/>"
print "<strike>v2.5.2 -> <code>#!/usr/bin/python2.5</code></strike><br/>"
print "v2.7.3 -> <code>#!/usr/bin/python2.7</code><br/>"
print "(noticing a pattern here?)"
print "</li>"
print "<li>end in '<code>.py</code>'</li>"
print "<li>print the '<code>Content-type: text/html\\n</code>' header"
print " in the first line if you want to view the output</li>"
print "<li>mark the file as executable: "
print "'<code>chmod 755 [filename.py]</code>'</li>"
print "</ol>"
print "<hr />"
print "This is a self printing file, full source code follows<br/>"
print 'Or you could view the source directly '
print '<a href="helloworld.txt">helloworld.txt</a>'
print "<hr />"
f = open('helloworld.py')
buff = f.readlines()
print "<pre>"
for line in buff:
# remove trailing newline
line = line.rstrip()
# escape less than/greater thans from < > to < > so they are viewable in html
# side effect: in a web browser it will look like it's doing nothing ;-)
line = line.replace("<","<")
line = line.replace(">",">")
print line
print "</pre>"
print "</body></HTML>"
if( __name__ == "__main__"):
try:
main()
except:
print "Content-type: text/html\n"
print "<HTML>"
print "<title>error?</title>"
print "<body>"
print "There was an error on the page<p/>"
print "Notes:<br/>"
print " exception handling is your friend</br>"
print " cgitb only works with current versions (>=2.3 ?) of Python<br/>"
print " not even an except block can recover from a print "
print "without a closing quote - you'll get an error 500 from the server"
print "<body>"
print "</HTML>"