persistentperl-users

Re: [Persistentperl-users] Followup to my STDOUT issue

[Sam H. <sa...@da...>]

 > When I look at Step 3 on how speedy works, I see that it does not pipe STDOUT to the backend?
 
That's true.  STDOUT is sent from the backend to the frontend as output
from the script.  STDOUT, is not sent from the frontend to the backend
for input.  STDOUT is an output channel.

> How am I supposed to read STDOUT from a previous pipe into my script??

With STDIN.
 
> Like the one I posted before.  I'm trying to write a filter that mail pipes through, but I dont want to invoke a perl interpreter for each email!   In order to get the envelope addresses, I have to read STDOUT from the qmail-smtpd pipe to my script.

That should work.  In pipes, the STDOUT of the previous command
(qmail in this case) becomes STDIN for the next command (your script).
Should work fine.  STDIN is passed by the frontend from the pipe to the
backend's STDIN, the backend reads it, produces output on STDOUT, then
STDOUT is copied from the backend to the frontend, where the frontend
emits it on its STDOUT.

RE: [Persistentperl-users] Followup to my STDOUT issue

[Dallas E. <da...@nm...>]

> -----Original Message-----
> From: Sam Horrocks [mailto:sa...@da...]
> Sent: Thursday, March 13, 2003 1:11 PM
> To: Dallas Engelken
> Cc: per...@li...;
> spe...@li...
> Subject: Re: [Persistentperl-users] Followup to my STDOUT issue=20
>=20
>=20
>  > When I look at Step 3 on how speedy works, I see that it=20
> does not pipe STDOUT to the backend?
> =20
> That's true.  STDOUT is sent from the backend to the frontend=20
> as output
> from the script.  STDOUT, is not sent from the frontend to the backend
> for input.  STDOUT is an output channel.
>=20
> > How am I supposed to read STDOUT from a previous pipe into=20
> my script??
>=20
> With STDIN.
> =20
> > Like the one I posted before.  I'm trying to write a filter=20
> that mail pipes through, but I dont want to invoke a perl=20
> interpreter for each email!   In order to get the envelope=20
> addresses, I have to read STDOUT from the qmail-smtpd pipe to=20
> my script.
>=20
> That should work.  In pipes, the STDOUT of the previous command
> (qmail in this case) becomes STDIN for the next command (your script).
> Should work fine.  STDIN is passed by the frontend from the=20
> pipe to the
> backend's STDIN, the backend reads it, produces output on STDOUT, then
> STDOUT is copied from the backend to the frontend, where the frontend
> emits it on its STDOUT.
>=20
>=20

Thanks for the response Sam.  My question to you is, why can I read the =
STDOUT when I use the perl or suidperl interpreter but not perperl. =20

Did you see my DEBUG output from my first post?  perl and suidperl can =
read the  =20

> SOUT LINE: Fda...@nm...Tda...@nm...=20

but perperl cannot.

Thanks,
Dallas

Re: [Persistentperl-users] Followup to my STDOUT issue

[Sam H. <sa...@da...>]

 > My question to you is, why can I read the STDOUT when I use the perl or suidperl interpreter but not perperl.  

 Because PersistentPerl does not support reading input from STDOUT.  The
 PersistentPerl code is not written to accomodate that.

 The reasons PersistentPerl doesn't support reading from STDOUT are:

 	1) It's not trivial to implement in the current way of doing things.

	2) An overwhelming majority of the the perl programs out there
	   use STDOUT only for output.  They do this because, by Unix
	   convention, STDOUT is used for output, not input.