Re: ignore header_only()?
On Fri, 4 Aug 2000, Vivek Khera wrote:
> > "NT" == Nathan Torkington <[EMAIL PROTECTED]> writes:
>
> NT> I see some programmers don't check header_only(). Are there
> NT> bad things in store if you don't? Or will Apache or the browser
> NT> simply ignore the body that gets created?
>
> My experience is apache just tosses the body for you. The programmer
> check is mainly an optimization from where I sit.
No, apache will send a body if you generate it even if the client just
sends a HEAD request. Example:
Head.pm:
package Head;
use strict;
use Apache::Constants 'OK';
sub handler {
my $r = shift; $r->content_type('text/plain'); $r->send_http_header;
print 'header_only() is ', ($r->header_only) ? "true\n" : "false\n";
return OK;
}
1;
httpd.conf:
===
LoadModule mime_modulelibexec/mod_mime.so
ClearModuleList
AddModule mod_mime.c
AddModule mod_so.c
AddModule mod_perl.c
SetHandler perl-script
PerlHandler Head
$ telnet localhost 80
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
HEAD / HTTP/1.0
HTTP/1.1 200 OK
Date: Mon, 07 Aug 2000 17:17:47 GMT
Server: Apache/1.3.12 (Unix) mod_perl/1.24
Connection: close
Content-Type: text/plain
header_only() is true
Connection closed by foreign host.
$ telnet localhost 80
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
GET / HTTP/1.0
HTTP/1.1 200 OK
Date: Mon, 07 Aug 2000 17:17:52 GMT
Server: Apache/1.3.12 (Unix) mod_perl/1.24
Connection: close
Content-Type: text/plain
header_only() is false
Connection closed by foreign host.
A mod_proxy ProxyPass frontend will discard the body if given a "HEAD"
request though.
Re: ignore header_only()?
Ken Williams wrote: > I know it was ages ago when you sent this patch, but what's the > rationale for having $r->sent_header() return 1 when it hasn't sent the > header? I didn't want to break anything. I'm hoping that people using sent_header are just checking for true, not for 1. (That's the way the mod_perl core does it.) > Shouldn't it be fixed to return 1 or 0 according to whether the > header has actually been sent? I'll let Doug decide. IMHO sent_header is the wrong method name. The current function should be called need_headers. (When PerlSendHeader is on, you don't need to send headers.) A new function should be added to let you know if the headers have already been sent. > If need be, perhaps it could distinguish like this: > >undef - headers have not been sent (PerlSendHeader on) >0 - headers have not been sent (PerlSendHeader off) >1 - headers have already been sent (PerlSendHeader off) >2 - headers have already been sent (PerlSendHeader on) That might break code because you're changing the truth values. My code didn't need to differentiate between the two unsent cases which is why I'm only returning 3 different values. - Ken
Re: ignore header_only()?
Ken Fox wrote: > I was using $request->sent_header and found out that it's > not terribly useful if PerlSendHeader is off -- sent_header > always returns 1. I changed mod_perl_sent_header so that > it returns 0, 1 or 2: > > 0 - headers have not been sent (PerlSendHeader on) > 1 - headers have not been sent (PerlSendHeader off) > 2 - headers have already been sent I know it was ages ago when you sent this patch, but what's the rationale for having $r->sent_header() return 1 when it hasn't sent the header? Shouldn't it be fixed to return 1 or 0 according to whether the header has actually been sent? If need be, perhaps it could distinguish like this: undef - headers have not been sent (PerlSendHeader on) 0 - headers have not been sent (PerlSendHeader off) 1 - headers have already been sent (PerlSendHeader off) 2 - headers have already been sent (PerlSendHeader on) But I'd rather just have it return 1 or 0, and have a seperate method that tells you whether PerlSendHeader is on or off.
Re: ignore header_only()?
> Ken Fox wrote: > > I was using $request->sent_header and found out that it's > > not terribly useful if PerlSendHeader is off -- sent_header > > always returns 1. I changed mod_perl_sent_header so that > > it returns 0, 1 or 2: > > > > 0 - headers have not been sent (PerlSendHeader on) > > 1 - headers have not been sent (PerlSendHeader off) > > 2 - headers have already been sent > > Is this the right list for change proposals? Should I re-submit my > patch? Yes it's the right list, and no, no need to resubmit. Personally I only commit bug fixes, and Doug looks at new features. He'll get around to it, he's just a bit busy at the moment. Thanks, -- Eric
Re: ignore header_only()?
On Fri, 4 Aug 2000, Ken Fox wrote: > > I was using $request->sent_header and found out that it's > > not terribly useful if PerlSendHeader is off -- sent_header > > always returns 1. I changed mod_perl_sent_header so that > > it returns 0, 1 or 2: > > > > 0 - headers have not been sent (PerlSendHeader on) > > 1 - headers have not been sent (PerlSendHeader off) > > 2 - headers have already been sent I do that sort of thing for AxKit, overriding the Apache class and re-blessing $r, and implementing a safer send_http_header() that remembers if the headers have already been sent. -- Fastnet Software Ltd. High Performance Web Specialists Providing mod_perl, XML, Sybase and Oracle solutions Email for training and consultancy availability. http://sergeant.org | AxKit: http://axkit.org
Re: ignore header_only()?
Ken Fox said: > Sorry to be a pain, but I still haven't heard anything back about my > proposal: > > Ken Fox wrote: > > I was using $request->sent_header and found out that it's > > not terribly useful if PerlSendHeader is off -- sent_header > > always returns 1. I changed mod_perl_sent_header so that > > it returns 0, 1 or 2: > > > > 0 - headers have not been sent (PerlSendHeader on) > > 1 - headers have not been sent (PerlSendHeader off) > > 2 - headers have already been sent > > Is this the right list for change proposals? Should I re-submit my > patch? > You could try: The dev list is for discussions about the development of the core mod_perl modules. Subscription information. a.. subscribe to the list: [EMAIL PROTECTED] b.. unsubscribe from the list: [EMAIL PROTECTED] c.. get help with the list: [EMAIL PROTECTED] Doug popped his head up a few weeks ago to say he's in read-only mode at the moment. I don't know why--maybe he's busy with v2 at the moment. If you don't have any luck on the dev list you could try mailing him directly, I guess. -- Jeremy Howard [EMAIL PROTECTED]
Re: ignore header_only()?
Ajit Deshpande wrote: > On Fri, Aug 04, 2000 at 04:22:29PM -0600, Nathan Torkington wrote: > > Thanks for the speedy response. You've now emboldened me to ask my > > second question: sometimes I see people not calling send_http_header() > > and yet their HTML still comes through. Does mod_perl sometimes > > automatically call this for you? > > Yep, its a configurable option. > > http://perl.apache.org/guide/config.html: > >PerlSendHeader On Sometimes I've seen people be really careful and use sent_header() to test if the headers have already been sent. But that only works with PerlSendHeader turned on... Sorry to be a pain, but I still haven't heard anything back about my proposal: Ken Fox wrote: > I was using $request->sent_header and found out that it's > not terribly useful if PerlSendHeader is off -- sent_header > always returns 1. I changed mod_perl_sent_header so that > it returns 0, 1 or 2: > > 0 - headers have not been sent (PerlSendHeader on) > 1 - headers have not been sent (PerlSendHeader off) > 2 - headers have already been sent Is this the right list for change proposals? Should I re-submit my patch? - Ken
Re: ignore header_only()?
On Fri, Aug 04, 2000 at 04:22:29PM -0600, Nathan Torkington wrote: > Thanks for the speedy response. You've now emboldened me to ask my > second question: sometimes I see people not calling send_http_header() > and yet their HTML still comes through. Does mod_perl sometimes > automatically call this for you? Yep, its a configurable option. http://perl.apache.org/guide/config.html: [..] PerlSendHeader On PerlSendHeader On tells the server to send an HTTP header to the browser on every script invocation. You will want to turn this off for nph (non-parsed-headers) scripts. The PerlSendHeader On setting invokes ap_send_http_header() after parsing your script headers. It is only meant for CGI emulation, and to send the HTTP header it's always better either to use $q->header from the CGI.pm module or to use $r->send_http_header using the Apache Perl API. [..] Ajit
Re: ignore header_only()?
Thanks for the speedy response. You've now emboldened me to ask my second question: sometimes I see people not calling send_http_header() and yet their HTML still comes through. Does mod_perl sometimes automatically call this for you? Nat
Re: ignore header_only()?
> "NT" == Nathan Torkington <[EMAIL PROTECTED]> writes: NT> I see some programmers don't check header_only(). Are there NT> bad things in store if you don't? Or will Apache or the browser NT> simply ignore the body that gets created? My experience is apache just tosses the body for you. The programmer check is mainly an optimization from where I sit. -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Vivek Khera, Ph.D.Khera Communications, Inc. Internet: [EMAIL PROTECTED] Rockville, MD +1-301-545-6996 GPG & MIME spoken herehttp://www.khera.org/~vivek/
