A simple piece of C code to print out the memory address of a specific environmental variable.

getenvaddr.c

#include <stdlib.h>
#include <stdio.h>

int main(int argc, char *argv[]) {
    char *addr;
    if (argc < 2) {
        printf("Usage:\n%s <environment variable name>\n", argv[0]);
        exit(0);
    }

    addr = getenv(argv[1]);
    if (addr == NULL)
        printf("The environment variable %s doesn't exist.\n", argv[1]);
    else
        printf("%s is located at %p\n", argv[1], addr);

    return(0);
}