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

int main (int argc, char **argv)
{
  if (putenv ("CONFTEST_putenv=val"))
    return 1;

  printf ("variable creation\n");
  printf ("internal: %s\n", getenv ("CONFTEST_putenv"));
  system ("echo external: %CONFTEST_putenv%");

  if (putenv ("CONFTEST_putenv=newval"))
    return 4;

  printf ("variable change with gnulib::putenv\n");
  printf ("internal: %s\n", getenv ("CONFTEST_putenv"));
  system ("echo external: %CONFTEST_putenv%");

  if (_putenv ("CONFTEST_putenv=newval"))
    return 5;

  printf ("variable change with _putenv\n");
  printf ("internal: %s\n", getenv ("CONFTEST_putenv"));
  system ("echo external: %CONFTEST_putenv%");

  /* Try to remove it.  */
  if (putenv ("CONFTEST_putenv"))
    return 2;

  /* Make sure it was deleted.  */
  if (getenv ("CONFTEST_putenv") != 0)
    return 3;

  return 0;
}