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Re: a couple more questions about variables and scope
From: |
Paul D. Smith |
Subject: |
Re: a couple more questions about variables and scope |
Date: |
Wed, 9 Jun 2004 11:04:53 -0400 |
%% "Robert P. J. Day" <address@hidden> writes:
rpjd> but that's clearly not enough. in addition, that make variable
rpjd> would also have to be exported so that it was available to all
rpjd> submakes, as an environment variable would be.
rpjd> perhaps a better question might be, at the beginning of the
rpjd> make, how *exactly* are environment variables added to the mix
rpjd> so that, once that processing is done, is there any record that
rpjd> those variables came from the calling environment as opposed to,
rpjd> say, being set as make variables and then exported? does make
rpjd> distinguish between those two?
When make starts, all the environment variables are automatically
created as make variables. They are marked as exported.
When a variable in a makefile is exported it is also marked as exported.
When make invokes a subprocess it goes through the make variables and
takes everything marked as exported, and puts it into the environment of
the subprocess.
So no, there is no distinction made.
--
-------------------------------------------------------------------------------
Paul D. Smith <address@hidden> Find some GNU make tips at:
http://www.gnu.org http://make.paulandlesley.org
"Please remain calm...I may be mad, but I am a professional." --Mad Scientist