Re: [Phpprintipp] Why not use cURL ?

[Thomas Harding]

Le 03/09/2010 22:45, Gabriel David a écrit :
> I was looking at your code for PHP::PRINT::IPP and wondered why you do 
> not use cURL <http://www.php.net/manual/en/book.curl.php>.
>
> IPP under Windows Server 2008 requires NTLM Authentication and cURL 
> supports it.

cURL cannot handle IPP requests, even if they are mainly HTTP1/1 POST 
request
 because of several reasons :

first, IPP HTTP POST request needs a CONTENT-LENGHT header, which is 
computed
from the specific IPP string ended by the 0x03 "character", immediately 
followed by
the file or string.

Second, a PDF or PostScript file can have an HUGE size, which could not 
be handled
because of PHP max memory settings (now far up to the initial 8Mbytes 
standard,
but not infinite), so PHP:PRINT:IPP http backend takes care of file 
size, add it to
the ipp command string size to complete content-lenght header, post the 
HTTP headers
and IPP command string, then streams the file by strips of N kilobytes 
from the beginning
to the EOF to the HTTP/IPP server, which saves for memory.

In case of computed strings to spool (eg "fpdf" output, the string 
length is added directly
to the IPP string length to build http header, and they are streamed 
together)

Third, cURL is written to handle "classic" GET/POST requests, also with 
multiple content
(given by your browser while you have enctype="multipart/form-data" in 
your web forms
to be able to upload files) for named files, but is "fixed" on classic 
HTTP client behavior
with multipart-form data handling as such as "boundary: 
R4anD0mstR1ng----" and so on
you can find in any mime multipart RFC documents.
This handling have nothing to do with IPP:
[http headers with content-lenght][blank line][ipp commands ending by  
0x03][content to print]
                                                                              
[.................content-length..............................]

Fourth, my first http backend was a modified one from (BSD licensed) 
Manuel Lemos
http which didn't use cURL yet. I think Manuel use cURL now, but don't 
know if he
still have our "string+file spooling" hack.

I deleted my files from Manuel Lemos site because of a different point 
of view on
distribution (while you can force users to register to get your files, 
and upload files
to the site was very painfull (no tarballs!), and because I switched on to
GNU Savannah which offers SVN/CVS/... versioning systems, with anonymous 
login
for anyone (and authenticated login for developers), and http and ftp 
download areas.
I wonder when GNU Savannah will offer for Debian add-ons repository we 
could fill
in ;p

So, (I think) Manuel Lemos's still develop his own http class I based on 
PHP:PRINT:IPP
first for backend, and he was adding cURL handling while I began to 
develop my own.
I  cannot guarantee cURL parts nor Manuel's http backend itself are 
still compatible with
my IPP class, and I'm not sure NTLM auth is part of RFCs for IPP allows 
NTLM auth
on http backend, which would make if not a peculiarity of M$ IPP 
implementation.

More, I would pass PHP:PRINT:IPP devel to a good programmer, because of
illness (too many work => nervous breakdown), and in lack of time (I'm in
the forces, so can be busied 24h a day 7 days on the week), but didn't find
any volunteer.

Last, I doubt that the M$Windows IPP server will handle your prints except
ASCII text files, because of print requests are handled directly by 
client programs
through the "printer driver".
Note I can be wrong on that point.

So, you can ever either adapt Manuel's http class (I think it handles 
both cURL and
NTLM auth) and/or BasicIPP yourself, with no warranty of printing 
success because
of "the printer driver problem".


[to gabriel] I set ml handler to approves your mails, but didn't expect 
anyone will
  add you in their responses to this thread
> /Gabriel David/
> /address@hidden <mailto:address@hidden>/
> /
> /

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HTH,
--
TH.