BUSTED while trying to do extra credit #2

ex17.c

@@ -4,18 +4,20 @@
 #include <errno.h>
 #include <string.h>
 
-#define MAX_DATA 512
-#define MAX_ROWS 100
+#define DEFAULT_MAX_DATA 512
+#define DEFAULT_MAX_ROWS 100
 
 struct Address {
     int id;
     int set;
-    char name[MAX_DATA];
-    char email[MAX_DATA];
+    char *name;
+    char *email;
 };
 
 struct Database {
-    struct Address rows[MAX_ROWS];
+    int max_data;
+    int max_rows;
+    struct Address rows[];
 };
 
 struct Connection {
@@ -93,11 +95,13 @@ void Database_write(struct Connection *conn)
     if(rc == -1) die("Cannot flush database.", conn);
 }
 
-void Database_create(struct Connection *conn)
+void Database_create(struct Connection *conn, int max_rows, int max_data)
 {
     int i = 0;
+    conn->db->max_rows = max_rows;
+    conn->db->max_data = max_data;
 
-    for(i = 0; i < MAX_ROWS; i++) {
+    for(i = 0; i < conn->db->max_rows; i++) {
         // make a prototype to initialize it
         struct Address addr = {.id = i, .set = 0};
         // then just assign it
@@ -107,17 +111,18 @@ void Database_create(struct Connection *conn)
 
 void Database_set(struct Connection *conn, int id, const char *name, const char *email)
 {
+    int max_data = conn->db->max_data;
     struct Address *addr = &conn->db->rows[id];
     if(addr->set) die("Already set, delete it first", conn);
 
     addr->set = 1;
-    char *res = strncpy(addr->name, name, MAX_DATA);
+    char *res = strncpy(addr->name, name, max_data);
     if(!res) die("Name copy failed", conn);
-    addr->name[MAX_DATA - 1] = '\0';
+    addr->name[max_data - 1] = '\0';
 
-    res = strncpy(addr->email, email, MAX_DATA);
+    res = strncpy(addr->email, email, max_data);
     if(!res) die("Email copy failed", conn);
-    addr->email[MAX_DATA - 1] = '\0';
+    addr->email[max_data - 1] = '\0';
 }
 
 void Database_get(struct Connection *conn, int id)
@@ -142,7 +147,7 @@ void Database_list(struct Connection *conn)
     int i = 0;
     struct Database *db = conn->db;
 
-    for(i = 0; i < MAX_ROWS; i++) {
+    for(i = 0; i < conn->db->max_rows; i++) {
         struct Address *cur = &db->rows[i];
 
         if(cur->set) {
@@ -153,19 +158,27 @@ void Database_list(struct Connection *conn)
 
 int main(int argc, char *argv[])
 {
-    if(argc < 3) die("USAGE: ex17 <dbfile> <action> [action params]", NULL);
+    if(argc < 3) die("USAGE: ex17 <dbfile> <action>[:max_data,max_rows] [action params]", NULL);
 
     char *filename = argv[1];
+
+    int max_data = DEFAULT_MAX_DATA;
+    int max_rows = DEFAULT_MAX_ROWS;
+
     char action = argv[2][0];
+    if(':' == argv[2][1]) {
+        sscanf(argv[2], "%c:%d,%d", &action, &max_data, &max_rows);
+    }
+
     struct Connection *conn = Database_open(filename, action);
     int id = 0;
 
     if(argc > 3) id = atoi(argv[3]);
-    if(id >= MAX_ROWS) die("There's not that many records.", conn);
+    if(id >= max_rows) die("There's not that many records.", conn);
 
     switch(action) {
         case 'c':
-            Database_create(conn);
+            Database_create(conn, max_rows, max_data);
             Database_write(conn);
             break;