string join() method

[Derek Basch]

Can anyone tell me why this CGI code outputs a blank page?
--------------------------------
self.output = []
self.setContentType("text/plain")
ascii_temp.seek(0)
self.output.extend(ascii_temp.read())
print ''.join(self.output)

def setContentType(self, type="text/xml"):
self.output.extend(["Content-type: ", type, "\n\r"])
---------------------------------

but this code works?:
---------------------------------
self.output = []
self.setContentType("text/plain")
print ''.join(self.output)
ascii_temp.seek(0)
print ascii_temp.read()

def setContentType(self, type="text/xml"):
self.output.extend(["Content-type: ", type, "\n\r"])

 

[Benjamin Niemann]

Can anyone tell me why this CGI code outputs a blank page?
--------------------------------
self.output = []
self.setContentType("text/plain")
ascii_temp.seek(0)
self.output.extend(ascii_temp.read())
print ''.join(self.output)

def setContentType(self, type="text/xml"):
self.output.extend(["Content-type: ", type, "\n\r"])
---------------------------------

but this code works?:
---------------------------------
self.output = []
self.setContentType("text/plain")
print ''.join(self.output)
ascii_temp.seek(0)
print ascii_temp.read()

def setContentType(self, type="text/xml"):
self.output.extend(["Content-type: ", type, "\n\r"])

First thing: HTTP header lines must be terminated by "\r\n" not "\n\r".
The headers are terminated by another "\r\n". I'm not sure (but I would bet
an Euro or two that it does), but perhaps the webserver sanitizes the
output of CGI script and converts plain "\n" into "\r\n" - if not then you
shouldn't use print to output the headers, because it only outputs
non-HTTPish "\n".

The output of your first script is

---------------------------------------
Content-type: text/plain\r\n
Allele...

 

[Damjan]

but perhaps the webserver sanitizes the output of CGI script and converts

plain "\n" into "\r\n"

Yes apache does this, since it adds its own headers anyway it will replace
all '\n' in the headers with '\r\n' and '\n\n' with '\r\n\r\n'.

 

[Kent Johnson]

Can anyone tell me why this CGI code outputs a blank page?

Maybe because it needs a blank line between the header and the body?

--------------------------------
self.output = []
self.setContentType("text/plain")
ascii_temp.seek(0)
self.output.extend(ascii_temp.read())

self.output.append() is probably what you mean. Try this:

self.output.append('\r\n')
self.output.append(ascii_temp.read())

print ''.join(self.output)

def setContentType(self, type="text/xml"):
self.output.extend(["Content-type: ", type, "\n\r"])

The above line will create a blank line because of the extra newline from print.

Kent

ascii_temp.seek(0)
print ascii_temp.read()

def setContentType(self, type="text/xml"):
self.output.extend(["Content-type: ", type, "\n\r"])