text: #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  
  int main(int argc, char** argv, char** environ)
  {
  	if (argc == 1)
  	{
  		char** env;
  		for (env = environ; *env != 0; env++)
  		{
  			const size_t len = strcspn(*env, "=");
  			char name[len+1];
  			strncpy(name, *env, len);
  			name[len] = 0;
  			const char *c = getenv(name);
  			printf ("getenv(\"%s\") -> ", name);
  			printf ("%s\n", c);
  		}
  	}
  	else
  	{
  		for (int i=1; i<argc; ++i)
  		{
  			const char *name = argv[i];
  			const char *c = getenv(name);
  			if (!c) return 1;
  			printf ("%s\n", c);
  		}
  	}
  	return 0;
  }
  