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Full Discussion: Beginners question about fork
Top Forums Programming Beginners question about fork Post 302373237 by jim mcnamara on Thursday 19th of November 2009 09:30:26 PM
Old 11-19-2009
Sending email using a command like mailx or sendmail requires a fork/exec on the child
side then wait on the parent side. This is exactly what the system() call does.

The alternative is to do what sendmail does in C code. system("/usr/bin/sendmail ... ") being infinitely simpler. IF you're sending 100K mail messages per day you should incorporate sendmail code, otherwise for a few dozen messages per day, consider system().

Start here to see what sendmail does, it is open source.

Code:
http://www.sendmail.org/

 

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LEARN ABOUT FREEBSD

mailer.conf

MAILER.CONF(5)						      BSD File Formats Manual						    MAILER.CONF(5)

NAME

     mailer.conf -- configuration file for mailwrapper(8)

DESCRIPTION

     The file /etc/mail/mailer.conf contains a series of lines of the form

     name program [arguments ...]

     The first word of each line is the name of a program invoking mailwrapper(8).  (For example, on a typical system /usr/sbin/sendmail would be
     a symbolic link to mailwrapper(8), as would newaliases(1) and mailq(1).  Thus, name might be ``sendmail'' or ``newaliases'' etc.)

     The second word of each line is the name of the program to actually execute when the first name is invoked.

     The further arguments, if any, are passed to the program, followed by the arguments mailwrapper(8) was called with.

     The file may also contain comment lines, denoted by a '#' mark in the first column of any line.

FILES

     /etc/mail/mailer.conf

EXAMPLES

     This example shows how to set up mailer.conf to invoke the traditional sendmail(8) program:

	   # Execute the "real" sendmail program located in
	   # /usr/libexec/sendmail/sendmail
	   sendmail	   /usr/libexec/sendmail/sendmail
	   send-mail	   /usr/libexec/sendmail/sendmail
	   mailq	   /usr/libexec/sendmail/sendmail
	   newaliases	   /usr/libexec/sendmail/sendmail

     This example shows how to invoke a sendmail-workalike like Postfix in place of sendmail(8):

	   # Emulate sendmail using postfix
	   sendmail	   /usr/local/sbin/sendmail
	   send-mail	   /usr/local/sbin/sendmail
	   mailq	   /usr/local/sbin/sendmail
	   newaliases	   /usr/local/sbin/sendmail

     This example shows how to invoke a sendmail-workalike with Exim (from ports) in place of sendmail(8):

	   # Emulate sendmail using exim
	   sendmail	   /usr/local/sbin/exim
	   send-mail	   /usr/local/sbin/exim
	   mailq	   /usr/local/sbin/exim -bp
	   newaliases	   /usr/bin/true
	   rmail	   /usr/local/sbin/exim -i -oee

     This example shows the use of the mini_sendmail package from ports in place of sendmail(8).  Note the use of additional arguments.

	   # Send outgoing mail to a smart relay using mini_sendmail
	   sendmail	   /usr/local/bin/mini_sendmail -srelayhost
	   send-mail	   /usr/local/bin/mini_sendmail -srelayhost

SEE ALSO

     mail(1), mailq(1), newaliases(1), mailwrapper(8), sendmail(8)

     postfix(1) (ports/mail/postfix), mini_sendmail(8) (ports/mail/mini_sendmail)

HISTORY

     mailer.conf appeared in NetBSD 1.4.

AUTHORS

     Perry E. Metzger <perry@piermont.com>

BUGS

     The entire reason this program exists is a crock.	Instead, a command for how to submit mail should be standardized, and all the "behave dif-
     ferently if invoked with a different name" behavior of things like mailq(1) should go away.

BSD
								  October 8, 2010							       BSD
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