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From: jsdy@hadron.UUCP (Joseph S. D. Yao)
Newsgroups: net.unix-wizards
Subject: Re: Setting environment variables within a C program.
Message-ID: <178@hadron.UUCP>
Date: Mon, 6-May-85 22:50:00 EDT
Article-I.D.: hadron.178
Posted: Mon May  6 22:50:00 1985
Date-Received: Fri, 10-May-85 08:20:18 EDT
References: <10166@brl-tgr.ARPA>
Organization: Hadron, Inc., Fairfax, VA
Lines: 18

>  freds_wife = Wilma
>  export fred_wife
> How do I change the value of freds_wife from Wilma to Betty within the C
> program, and get the environment to understand the change later?

You can't.  Environment variables are exported to children, not vice-
versa.  The C prog is child of the shell.  However, if the program
produces no other output, you can get the shell to change itself by
printing out the commands:
	printf("freds_wife=Betty; export freds_wife\n");
and then:
	$ eval `prog`
This can be used profitably with, e.g., 'tset' to set TERM and TERMCAP.

However, a second, more difficult obstacle is that Betty loves Barney
and Wilma won't divorce Fred.	;-)

	Joe Yao		hadron!jsdy@seismo.{ARPA,UUCP}