Print the environment variables using environ

Question

How to print the environment variables in a C program using \"environ\".

extern char **environ

Answer 1

Do you mean

int main(int argc, char **argv, char **envp)
{
    while(*envp!=null) {
        printf("%s\n", *envp);
        envp++;
    }
    return 0;
}

Answer 2

#include <unistd.h>
#include <stdio.h>

extern char **environ;
//...

int i = 0;
while(environ[i]) {
  printf("%s\n", environ[i++]); // prints in form of "variable=value"
}