$ gcc -g -o test -I /usr/lib64/perl5/CORE -L /usr/lib64/perl5/CORE -lperl mini.c
$ ./test 
first time
going to return it: aaa
SV = PV(0x2001c78) at 0x2003d80
  REFCNT = 1
  FLAGS = (TEMP,POK,pPOK)
  PV = 0x2019de0 "aaa"\0
  CUR = 3
  LEN = 8
again
going to return it: aaa
SV = PV(0x2001c78) at 0x2003d80
  REFCNT = 1
  FLAGS = (TEMP,POK,pPOK)
  PV = 0x2019de0 "aaa"\0
  CUR = 3
  LEN = 8
and again
going to return it: aaa
SV = PV(0x2001c78) at 0x2003d80
  REFCNT = 1
  FLAGS = (TEMP,POK,pPOK)
  PV = 0x2019de0 "aaa"\0
  CUR = 3
  LEN = 8