Skip to Content
Sendmail, 3rd Edition
book

Sendmail, 3rd Edition

by Bryan Costales
December 2002
Intermediate to advanced
1232 pages
56h 38m
English
O'Reilly Media, Inc.
Content preview from Sendmail, 3rd Edition

Class Configuration Commands

The five forms for the class configuration command are the following:

CX list         values from configuration file 
CX $=Y          copy values from another class (V8.10 and above) 
FX /file        values from a disk file 
FX |program     values via another program 
FX key@database values from a database map (V8.12 and above)

The class configuration command starts with either the letter C or F, which must begin a line. The C says values will be assigned as a part of the configuration command. The F says values will be assigned from an external file, program, or database map.

The C or F is immediately followed (with no intervening whitespace) by the name of the class (the X in the preceding commands). A class name is any single ASCII character or, beginning with V8.7 sendmail, a multicharacter name enclosed in curly braces:

CX list             all versions 
C{LongName} list    beginning with V8.7

See Section 21.4.2 for a full discussion of how to use multicharacter names.

Note that classes are separate from macros, so they can both use the same letter or name with no conflict.

The sendmail program reserves the lowercase letters for its own use as internally defined class names. All uppercase letters and all names that begin with uppercase letters are available for your use.

The C Class Command

The C form of the class command causes values to be assigned from within the configuration file. In general, the C class command looks like this:

CX list            values from configuration file 
C{XX} list ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

AirBnbBlueOriginElectronic ArtsHomeDepotNasdaqRakutenTata Consultancy Services

QuotationMarkO’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
QuotationMarkI wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
QuotationMarkI’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
QuotationMarkI'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Mark W.
Embedded Software Engineer

You might also like

sendmail, 4th Edition

sendmail, 4th Edition

Bryan Costales, Claus Assmann, George Jansen, Gregory Neil Shapiro
Postfix

Postfix

Richard Blum

Publisher Resources

ISBN: 1565928393Errata Page