eof without closing the pipe

[csorensen]

the problem: I need to send a bunch of email without using cc, bcc or anything like that.
I would like to find a way to send an email message without closing the pipe


unfortunately I have no idea how to do this so I am stuck opening and closing sendmail for each email address in the array

any ideas ??

foreach (@mail_to) { 

open(SENDMAIL, "|$sendmail") or die "Cannot open $sendmail: $!";

        print SENDMAIL "To: $_ \n";
        print SENDMAIL "From: csorensen\@uptimeresources.net \n";
        print SENDMAIL "Subject: South African tourism survey \n";
        print SENDMAIL "Content-type: text/plain \n\n";
        print SENDMAIL $content;

close(SENDMAIL);
}

I moved the FIFO outside the loop and kept the print statements inside.. it created one MONSTER email for everyone and sent it to the first address.. oops !

[cleen]

I know Im going to get flamed for this becuase Im not using a module, but its quick and it works, plus that its quicker becuase it doesnt even open up a pipe..It uses a simple socket connection to a sendmail server (just one)

#!/usr/bin/perl
use strict;
use Socket;

my @users=('[e-mail]', '[e-mail]', '[e-mail]
+m');
my $mailhost="localhost";

my $myemail="mark\@cidera.com"; # Your email address

# this is just the subject and body of the message
# you can get this information from anywhere I just
# put it in here for the sake of example
my $subject= "hi";
my $data = "hi hi hi hi there";
my $userz;

socket(MAIL,PF_INET,SOCK_STREAM,getprotobyname('tcp'));
connect(MAIL,sockaddr_in(25,inet_aton($mailhost)));

select(MAIL);

$|=1;
select('stdout');

print MAIL "HELO blah.com\n";

foreach $userz (<@users>) {
 print MAIL "MAIL FROM: $myemail\n";
 print MAIL "RCPT TO: $userz\n";
 print MAIL "DATA\n";
 print MAIL "Subject: $subject\n";
 print MAIL "$data\n";
 print MAIL ".\n";
}

print MAIL "quit\n";
close(MAIL);

This works becuase it doesnt quit the sendmail connection till after all the emails have been sent to each person in your @users array seperatly.

I know this isnt EXACTLY what you were looking for, but its just another way to do this.

[c-era]

It's nice to see someone else who uses socket (not socket.pm) and knows a protocol or two.

[eduardo]

now, maybe i am mistaken... however, opening up a socket connection, no matter how simple, should be MARKEDLY slower than opening up a pipe, no matter what the situation. If you are opening up a socket to a host you have to deal with:
• TCP/IP overhead
• Network Transport Layer Overhead
• Communicational Latency
• The fact that you are communicating via external means, instead of the bus!
however, if you are opening up a pipe, to a process on the local machine then the situation is:
• there is NO TCP/IP overhead
• there is NO network layer overhead
• the communicational latency is the velocity at which the receiving process can aquire STDIN
• and you are communicating through memory and the bus, which have a MUCH greater bandwith and throughput than most any network connection!
if speed is your constraint, and you are attempting to maximize the throughput (here being messages per minute) I can not conceive of a way faster than communicating directly with sendmail through a pipe.


UPDATE: thanks to lhoward i have now learned that in modern operating systems, much to my suprise, the TCP subsystem has been optimized WAY better than I ever thought it would be, so, my entire coment above, should be disreguarded and i should be flogged for not having benchmarked in the first place :) keep the learning coming...

[lhoward]

Opening a socket is typically as fast or faster than opening a pipe.

Pipe issues:

• Have the overhead of starting a separate process. (you may or may not have this overhead when doing a TCP socket connection depending on if the server is forking or threading)
socket/TCP port issues:
• Most OSes have highly optimized TCP/IP stacks, generally much more optmized than the OSes core pipe processing functions. For today's applications network performance is typically much more important than pipe performance.
• localhost TCP/IP connections (where client and server are on the same host) do not go out "on the wire", they are typically highly optimized with direct memory-to-memory exchange of the data. Localhost network connections have practially 0 network overhead.

[t0mas]

I will not flame you. Looks like a nice way to do the job. There is not many who speak "natively" with sendmail nowdays ;)

/brother t0mas

[chromatic]

The author of Mail::Bulkmail claims it can process at least 884 messages per minute. If you promise your intentions are noble, have a look at that module.

[csorensen]

thanks .. people have mentioned that module to me before. I was hoping that someone knew a command that sent "eof" or something similiar to sendmail.

[Shendal]

How about this:


open(SENDMAIL"|$sendmail") or die "Cannot open $sendmail: $!";

        print SENDMAIL "To: " . join ",",@mail_to . "\n";
        print SENDMAIL "From: csorensen\@uptimeresources.net \n";
        print SENDMAIL "Subject: South African tourism survey \n";
        print SENDMAIL "Content-type: text/plain \n\n";
        print SENDMAIL $content;

close(SENDMAIL);

[PipTigger]

Would this join create an enormously fat To: line that would get sent to everybody in it or does it do something more subtle?

-PipTigger

p.s. Initiate Nail Removal Immediately!

[Shendal]

It would create an enormously fat To: line. I guess you could use bcc to hide that, but the original question didn't want to use bcc. Another choice is using bulkmail, which has already been suggested by someone else.