October 2007
Intermediate to advanced
1308 pages
161h 13m
English
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APPENDDEF( )
Append to an existing define Build directive
The APPENDDEF( ) m4 directive
allows you to append new information to information
that was previously defined. To illustrate, consider
that the locations of your #include files are sometimes preset in
the appropriate devtools/OS
directory. For OS/UXPDS.V10, for example, the
default is:
-I/usr/include -I/usr/ucbinclude
You can use this APPENDDEF( ) directive to add another directory to this list, without erasing what is already there:
APPENDDEF(`confINCDIRS', `-I/usr/local/include/db')
This causes the new directory to be appended to the declaration in the previous example:
-I/usr/include -I/usr/ucbinclude -I/usr/local/include/db
Even when you are not sure whether a macro has been given a value by default, you can safely use this APPENDDEF( ) directive because no harm is caused by appending to an empty definition. See also PREPENDDEF( ) in PREPENDDEF( ) on page 102.
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O’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.
I 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.
I’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.
I'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.