Tried to work on fixing message string bug

README.md

@@ -0,0 +1,14 @@
+## Chat server
+This is a simple, barely-working chat server (which uses a custom protocol). It is written in C, and relies on BSD sockets.
+
+##Usage
+To use it, compile the program with `make`.
+
+
+
+
+TODO:
+-  Finish README
+-  Implement password authentication
+-  Fix bugs with message string manipulation (the actual message isn't being stored correctly, and contains extra characters).
+-  Do additional testing to ensure that everything works correctly (it probably doesn't).

main.c

@@ -16,6 +16,7 @@
 #define BUFFER_SIZE 10000
 #define MAX_CONNECTIONS 100
 #define DATA_SIZE 50000
+#define MESSAGE_SIZE 50000
 
 User** create_user_list(char* filename);
 void sigint_handler(int dummy);
@@ -80,6 +81,9 @@ int main() {
 			}
 
 			for (int i=1; i < MAX_CONNECTIONS; i++) {
+
+				memset(data,0x00,DATA_SIZE);
+
 				if (FD_ISSET(conn_sockets[i],&read_fd_set)) {
 
 					while ( strstr(buffer,"END_OF_DATA") == NULL ) {
@@ -125,8 +129,10 @@ int main() {
 								printf("Message intended for %s\n",to_user[i]->username);
 							}
 						}
-	
-						char* message_string = fetch_message_string(data);
+
+						char* message_string = malloc(sizeof(char) * MESSAGE_SIZE);	
+						memset(message_string, 0x00, MESSAGE_SIZE);
+						message_string = fetch_message_string(data);
 						if (message_string == NULL) {
 							printf("Invalid message.\n");
 							return -10;

message_helpers.c

@@ -25,26 +25,34 @@ char* fetch_from_string(char* message, char* indicator) {
 }
 
 char* fetch_message_string(char* message) {
-	int num_of_terminators;
 
-	char* start = strstr(message,"START_OF_MESSAGE");
+	char* message_copy = malloc(strlen(message));
+	strcpy(message_copy,message);
+
+	int num_of_terminators = 0;
+	int start_index = 0;
+	int end_index = 0;
+	int message_length = 0;
+
+
+	char* start = strstr(message_copy,"START_OF_MESSAGE");
 	if (start == NULL) {
 		return NULL;
 	}
-	int start_index = start - message;
+	start_index = start - message_copy;
 	start_index += strlen("START_OF_MESSAGE");
 
-	while (*(message + start_index) == '\n' || *(message + start_index) == '\r') {
+	while (*(message_copy + start_index) == '\n' || *(message_copy + start_index) == '\r') {
 		start_index++;
 	}
 	
-	char* end = strstr(message,"END_OF_MESSAGE");
+	char* end = strstr(message_copy,"END_OF_MESSAGE");
 	if (end == NULL) {
 		return NULL;
 	}
-	int end_index = end - message;
+	end_index = end - message_copy;
 
-	if (*(message + end_index-2) = '\r') {
+	if (*(message_copy + end_index-2) == '\r') {
 		num_of_terminators = 2;
 	} else {
 		num_of_terminators = 1;
@@ -52,15 +60,15 @@ char* fetch_message_string(char* message) {
 
 	end_index -= num_of_terminators;
 
-	int message_length = end_index - start_index;
+	message_length = end_index - start_index;
 	char* message_string = malloc(message_length + 2);
 
-	printf("Message length is %d\n",message_length);
+	printf("Message goes from %d to %d\n",start_index,end_index);
 
 	for (int i=0; i<message_length; i++) { /* The reason the upper-bound is message_length-1 is because the last 
 						character is a new-line, which the user would not have typed. */
 
-		*(message_string + i) = *(message + start_index + i);
+		*(message_string + i) = *(message_copy + start_index + i);
 		printf("%c",*(message_string + i));
 	}