Mine

#define ILLEGAL_FILE_NAME 'F'#define ILLEGAL_IP_ADDRESS 'I'#define ILLEGAL_UID 'U'#define ILLEGAL_PORT 'P'#define ILLEGAL_PROGRAM 'R'#define OK '\0'struct ElementList {  char *element;  struct ElementList *next;};struct ConfigLine {  struct ElementList *uids;  struct ElementList *programs;  struct ElementList *IPAddresses;  struct ElementList *ports;};struct ConfigEntry {  char *uid;  char *program;  char *IPAddress;  int port;};struct FirewallConfig {  struct ConfigEntry *entry;  struct FirewallConfig *left;  struct FirewallConfig *right;};extern int compareEntry (struct ConfigEntry *,  struct ConfigEntry *);extern struct ConfigLine *parseLine (char *, int *);