1#include <stdio.h>
 2#include <stdlib.h>
 3#include <string.h>
 4#include <unistd.h>
 5
 6static const char* alias_name = "ALTER_EGO";
 7
 8char* greet(char* name) {
 9  char* alias = getenv(alias_name);
10  char* buffer = (char*)malloc(128);
11  snprintf(buffer, 128, "Hello %s!\n", alias == NULL ? name : alias);
12  return buffer;
13}
14
15int main(int argc, const char *argv[])
16{
17  printf("%s\n", greet("mo"));
18  return 0;
19}