Basic input sanatization:

Created new library to deal with user input.
Implemented check in client to prevent C-d spamming the server.
C-d now exits.
Implemented check in client to prevent clients sending messages containing only newlines
to the server.

src/SilverMUDClient.c

@@ -7,6 +7,7 @@
 #include <arpa/inet.h>
 #include <sys/socket.h>
 #include "misc/texteffects.h"
+#include "misc/inputhandling.h"
 #define MAX 1024
 #define PORT 5000
 #define SA struct sockaddr
@@ -20,11 +21,16 @@ void * messageSender(void * sockfd)
 	{
 		bzero(sendBuffer, MAX);
 		printf("COMM-LINK> ");
-		fgets(sendBuffer, MAX, stdin);
-		if(sendBuffer[0] != '\n');
+		if(fgets(sendBuffer, MAX, stdin) == NULL)
 		{
-			write((long)sockfd, sendBuffer, MAX);
+			exit(0);
 		}
+		userInputSanatize(sendBuffer, MAX);
+		if(sendBuffer[0] == '\n')
+		{
+			continue;
+		}
+		write((long)sockfd, sendBuffer, MAX);
         }
 }
 
@@ -35,9 +41,9 @@ void * messageReceiver(void * sockfd)
 	while (1)
 	{
 		read((long)sockfd, receiveBuffer, MAX);
-		slowprint("\nUSER-MESSAGE: ", 8000);
-		slowprint(receiveBuffer, 8000);
-		slowprint("\nCOMM-LINK (CONT.)> ", 8000);
+		slowPrint("\nUSER-MESSAGE: ", 8000);
+		slowPrint(receiveBuffer, 8000);
+		slowPrint("\nCOMM-LINK (CONT.)> ", 8000);
 		bzero(receiveBuffer, MAX);
 	}
 }
@@ -57,7 +63,7 @@ int main(int argc, char **argv)
 	}
 	else
 	{
-		slowprint("Socket successfully created.\n", 8000);
+		slowPrint("Socket successfully created.\n", 8000);
 	}
 	bzero(&servaddr, sizeof(servaddr));
   
@@ -76,12 +82,12 @@ int main(int argc, char **argv)
 	// Connect the server and client sockets, Kronk:
 	if (connect(sockfd, (SA*)&servaddr, sizeof(servaddr)) != 0)
 	{
-		slowprint("Connection with the Silverkin Industries Comm-Link Server Failed:\nPlease contact your service representative.\n", 8000);
+		slowPrint("Connection with the Silverkin Industries Comm-Link Server Failed:\nPlease contact your service representative.\n", 8000);
 		exit(0);
 	}
 	else
 	{
-		slowprint("Connected to the Silverkin Industries Comm-Link Server:\nHave a pleasant day.\n", 8000);
+		slowPrint("Connected to the Silverkin Industries Comm-Link Server:\nHave a pleasant day.\n", 8000);
 	}
 	
 	// Run a thread to send messages, and use main to recieve.

src/SilverMUDServer.c

@@ -27,8 +27,8 @@ int main()
 	struct sockaddr_in serverAddress, clientAddress;	
 
 	// Give an intro: Display the Silverkin Industries logo and splash text.
-	slowprint(logostring, 3000);
-	slowprint("\n--==== \033[33;40mSILVERKIN INDUSTRIES\033[0m COMM-LINK SERVER ====--\nVersion Alpha 0.1\n", 5000);
+	slowPrint(logostring, 3000);
+	slowPrint("\n--==== \033[33;40mSILVERKIN INDUSTRIES\033[0m COMM-LINK SERVER ====--\nVersion Alpha 0.1\n", 5000);
 	 
 	// Initialize the sockets to 0, so we don't crash.
 	for (int index = 0; index < maxClients; index++)  
@@ -46,7 +46,7 @@ int main()
 
 	else
 	{
-		slowprint(" Socket creation is \033[32;40mGREEN.\033[0m\n", 5000);
+		slowPrint(" Socket creation is \033[32;40mGREEN.\033[0m\n", 5000);
 	}
 
 	bzero(&serverAddress, sizeof(serverAddress));
@@ -64,7 +64,7 @@ int main()
 	}
 	else
 	{
-		slowprint(" Socket binding is \033[32;40mGREEN.\033[0m\n", 5000);
+		slowPrint(" Socket binding is \033[32;40mGREEN.\033[0m\n", 5000);
 	}
 	
 	// Let's start listening:
@@ -75,7 +75,7 @@ int main()
 	}
 	else
 	{
-		slowprint(" Server listening is \033[32;40mGREEN.\033[0m\n", 5000);
+		slowPrint(" Server listening is \033[32;40mGREEN.\033[0m\n", 5000);
 	}
 	length = sizeof(clientAddress);
 

src/misc/inputhandling.c

@@ -0,0 +1,16 @@
+// inputhandling.c: Implementation of input handling library for SilverMUD.
+// Barry Kane, 2021.
+#include <ctype.h>
+
+void userInputSanatize(char * inputString, int length)
+{
+	for(int index = 0; index <= length; index++)
+	{
+		if(!isprint(inputString[index]))
+		{
+			inputString[index] = '\n';
+			inputString[index + 1] = '\0';
+			break;
+		}
+	}
+}

src/misc/inputhandling.h

@@ -0,0 +1,10 @@
+// inputhandling.h: Header file for the inputhandling library for SilverMUD.
+// Barry Kane, 2021
+#ifndef INPUTHANDLING_H
+#define INPUTHANDLING_H
+#include <ctype.h>
+
+// Sanatize user input to ensure it's okay to send to the server:
+void userInputSanatize(char * inputString, int length);
+
+#endif

src/misc/texteffects.c

@@ -3,7 +3,7 @@
 #include <stdio.h>
 #include <unistd.h>
 
-void slowprint(char * stringToPrint, int delay)
+void slowPrint(char * stringToPrint, int delay)
 {
 	int characterIndex = 0;
 	while(stringToPrint[characterIndex] != '\0')

src/misc/texteffects.h

@@ -1,9 +1,11 @@
+// texteffects.h: Header file for the texteffects library for SilverMUD.
+// Barry Kane, 2021.
 #ifndef TEXTEFFECTS_H_
 #define TEXTEFFECTS_H_
 #include <stdio.h>
 
 // A fancy, character by character print. Similar to a serial terminal with lower baud rate.
-void slowprint(char * stringToPrint, int delay);
+void slowPrint(char * stringToPrint, int delay);
 
 // A string containing an ASCII art version of the Silverkin Industries logo.
 char * logostring = "                                                         ///////\n                                 //////////////////////////////////////////\n                   ///////////////////////////////////////////////////////////\n        //////////                                  ////////////////////////////\n   ###   #  #    #     # #####  ###   # #  #  #   #            /////////////////\n  ###    #  #     #   #  ##     #  #  ##   #  ##  #               //////////////\n     ##	 #  #      # #   #      ###   # #  #  # # #                   /////////\n  ####   #  ###     #    #####  #  #  #  # #  #  ##                    ///////\n         #  ##   #  #####   #   #   ### ### ###  # #####  ###          ////// \n         #  # #  #  #    #  #   #  ##    #  #  # # ##    ##             ////\n       	 #  #  # #  #    #  #   #    ##  #  ###	 # #   	   ##	       	//\n         #  #  ###  #####   #####  ###   #  #  # # ####  ###           //\n";