How to get the modified environmental variables using c programme in Mac using bash terminal

Question

Hi,

I want to get the modified environment variables using C programme in Mac using bash terminal how to get it?

if i use getenv i will get only the default system defined environment variables but i am not getting the modified one. how to get it

Answer 1

#include <stdio.h>
int main()
{
        setenv("PATH","/mypath",1);
        printf("%s\n",getenv("PATH"));
        return(0);
}

The above program outputs:

/mypath

If however you execute env in bash after your C program, you will get the PATH value which is set by default for bash.

$ env
...
PATH=/usr/lib/qt-3.3/bin:/usr/kerberos/sbin:/usr/kerberos/bin:/usr/lib/ccache:/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin:/home/user/bin
...

This is because the environment variables are modified only for that particular process which is running the C program, & not for the process running bash.

Edit:

Writing env.c as:

#include <stdio.h>
int main()
{
        printf("%s\n",getenv("PATH"));
        return(0);
}

followed by:

$ gcc env.c
$ export PATH=/bin
$ ./a.out

gives:

/bin

I don't see why it should be any different. (Did you do all the steps that I have done above?)