Re: how to set an environment variable from within a makefile

[Michael Ludwig]

Philip Guenther schrieb am 17.03.2012 um 21:04 (-0700):

> In UNIX, when a process creates a child process, the child process
> gets its own environment, separate from that of the process that
> created it.  There's nothing the child can do to affect the
> environment of its parent.
> 
> Programs that have needed to do this are generally written to output
> to stdout the variable assignments that are desired and then document
> that their caller, the program that invokes them, should capture that
> output and evaluate it.  For example, the 'tset' program […]

Another example is ssh-agent :

$ ssh-agent
SSH_AUTH_SOCK=/tmp/ssh-jimlbwZEu764/agent.764; export SSH_AUTH_SOCK;
SSH_AGENT_PID=5064; export SSH_AGENT_PID;
echo Agent pid 5064;

Michael