UNIX for Advanced & Expert Users

hi,

I have one environment variable like path in my system.But in my program i need to change that path .suppose it has a value "config" now i need to chage it as "config1" or something else.i need to use that variable for complete project.It means at first it will use the old path but after sometime i need to convert that path .So please tell me any way for doing this.setenv() i tried but it's not working.

to retrieve the old variable from the env
use getenv
and to set new value to env variable as you have said it is
setenv

if you still find some issues, the post the code and how you had tried that?

I'm not sure what your intention is.
Your program can only set the environment for itself and any children it would fork.
It can however not set the environment of its own parent.
Since you mentioned the getenv() and setenv() syscalls I assume you are referring to some C code.
On the other hand different languages use different accessors to the process'es environment.
While C shell compatible interpreters also use the setenv built-in
Bourne shell compatibles use the export built-in to mark an environment variable
(Bash additionally offers the declare -x).
Perl on the other hand uses the global hash %ENV in a package's symbol table.

And those env variables that are not part of the profile should be exported for the child to make use of it.
I believe the hierarchy doesnt goes from child to parent, and only from parent to child.
Yes, I had specified them to make use in 'C' code only.

hi,

I am writing c++ code .In that i need to set the environment variable.

suppose previously i have environment variable like path="something" now i need to change the path value to some othervalue . so that some other program will access that path value and by using new path value my program will work.so please tell me the way for this.