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linuxManish 02-27-2009 11:58 AM

environment variable access across different process on the system
 
Hi,
Is there any way to access some of the environment variables of one process in another process ?

for example, a daemon running on the system has some environment variable exported. Now I'm writing a c++ utility that will run independently of the daemon, but it needs some of the environment variables of the daemon for its functionality. Since this utility is not the child process of the daemon process, it doesn't have any access to those environment variable. So, is there any way to access those variables ?

One way I thought was to somehow make this utility a child process of that daemon, but don't know how it can be done ?

Please enlighten on this.
Thanks

theNbomr 02-27-2009 12:24 PM

Even when there is a parent/child relationship between processes, the child only receives an independent copy of the parent's environment. Without using some planned interprocess communication (IPC), there is no direct way of sharing environment or any other part of a process's context. To make it any other way would be a security problem.
--- rod.

linuxManish 02-27-2009 12:40 PM

ok, barring security concerns, is it still possible to do something to get those variables ?

theNbomr 02-27-2009 12:59 PM

Yes, it is possible to share information of almost any sort (not just env vars) between processes. To do so requires the use of an appropriate IPC mechanism, and all participating process must be programmed to behave appropriately for the application. Simply peeking behind a process's curtain to see its environment variables cannot be done directly.
For a good primer on IPC, see Beej's Guide to IPC.
--- rod.


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