diff --git a/src/apps/gbdb.c b/src/apps/gbdb.c
index de1d397..ecc924a 100644
--- a/src/apps/gbdb.c
+++ b/src/apps/gbdb.c
@@ -142,7 +142,7 @@ static void mem_dump(char *filename)
 	}
 	strip_newline(token);
 	dump_file = fopen(token, "w");
-	if(dump_file < 0) {
+	if(dump_file == NULL) {
 		printf("Failed to open mem dump file: %d\n", errno);
 		return;
 	}
@@ -286,7 +286,10 @@ static void load_file_to_buffer(char *filename, uint8_t *buffer, size_t size)
 	fseek(prog_file, 0, SEEK_END);
 	filesize = ftell(prog_file);
 	fseek(prog_file, 0, SEEK_SET);
-	fread(buffer, MIN(filesize, size), 1, prog_file);
+
+	if (fread(buffer, MIN(filesize, size), 1, prog_file) < 0) {
+		printf("Failed to read filed: %d\n", errno);
+	}
 	fclose(prog_file);
 
 }
@@ -412,12 +415,12 @@ static void breakpoint(char *arg_list)
 		memset(breakpoints, 0, sizeof(breakpoints));
 		tri_init(&commands);
 		tri_add_string(&commands, "add", set_breakpoint);
-		tri_add_string(&commands, "set", set_breakpoint);
-		tri_add_string(&commands, "delete", delete_breakpoint);
-		tri_add_string(&commands, "remove", delete_breakpoint);
-		tri_add_string(&commands, "info", display_breakpoints);
-		tri_add_string(&commands, "display", display_breakpoints);
-		tri_add_string(&commands, "list", display_breakpoints);
+		tri_add_string(&commands, "set",  set_breakpoint);
+		tri_add_string(&commands, "delete",  delete_breakpoint);
+		tri_add_string(&commands, "remove",  delete_breakpoint);
+		tri_add_string(&commands, "info",  display_breakpoints);
+		tri_add_string(&commands, "display",  display_breakpoints);
+		tri_add_string(&commands, "list",  display_breakpoints);
 		init = true;
 	}
 
@@ -462,11 +465,20 @@ static bool cpu_at_breakpoint(void)
 	return breakpoint_is_at_addr(lr35902_get_reg_16(&cpu, LR35902_REG_PC));
 }
 
+static void process_cmd(char *cmd)
+{
+
+}
+
 int main(int argc, char **argv)
 {
 	struct tri commands;
-	char line_buffer[INPUT_MAX_LEN];
-	char old_buffer[INPUT_MAX_LEN];
+	char line_buffer[INPUT_MAX_LEN]; /* Buffer for input command */
+	char old_buffer[INPUT_MAX_LEN]; /* Buffer for previous input */
+	char cmd_buffer[INPUT_MAX_LEN]; /* Buffer for command parsing */
+
+	line_buffer[0] = '\0';
+	old_buffer[0] = '\0';
 
 	tri_init(&commands);
 	tri_add_string(&commands, "step", step);
@@ -481,6 +493,7 @@ int main(int argc, char **argv)
 	tri_add_string(&commands, "dump", mem_dump);
 	tri_add_string(&commands, "peek", peek);
 	tri_add_string(&commands, "help", help);
+	tri_add_string(&commands, "?", help);
 	tri_add_string(&commands, "breakpoint", breakpoint);
 	tri_add_string(&commands, "reset", init);
 
@@ -488,37 +501,74 @@ int main(int argc, char **argv)
 
 	while (1) {
 		bool ambiguous;
-		char *remainder;
 		gbdb_cmd* cmd;
-		char *cmd_string;
 
+		/* String to use for input (line_buffer or
+		 * old_buffer) */
+		char *cmd_str;
+
+		/* Current point in the line (there may be more than
+		 * one command on a line) */
+		char *process_str;
+
+		/* String containing the arguments following a command */
+		char *arg_str;
+		
 		show_prompt();
-		fgets(line_buffer, INPUT_MAX_LEN, stdin);
+		cmd_str = fgets(line_buffer, INPUT_MAX_LEN, stdin);
+		if (cmd_str == NULL) {
+			printf("\n");
+			return 0;
+		}
+
 		if (line_buffer[0] != '\n') {
-			cmd_string = line_buffer;
-		} else {
-			cmd_string = old_buffer;
-		}
-		strip_newline(cmd_string);
-		remainder = strchr(cmd_string, ' ');
-		if (remainder != NULL) {
-			remainder[0] = '\0';
-			remainder++;
-		}
-
-		cmd = tri_get_string_autocomplete(&commands, cmd_string, &ambiguous);
-
-		if (ambiguous) {
-			printf("ambiguous command: '%s'\n", cmd_string);
-		} else if (cmd == NULL) {
-			printf("unrecognized command: '%s'\n", cmd_string);
-		} else {
-			cmd(remainder);
-		}
-
-		if (cmd_string == line_buffer) {
+			cmd_str = line_buffer;
 			strncpy(old_buffer, line_buffer, INPUT_MAX_LEN);
+		} else {
+			cmd_str = old_buffer;
 		}
+
+		process_str = cmd_str;
+		do {
+			int i;
+
+			while (process_str[0] == ' ') { process_str++; };
+			for (i = 0;; i++) {
+				if (process_str[i] == '\0' ||
+				    process_str[i] == ';') {
+					cmd_buffer[i] = '\0';
+					break;
+				} else {
+					cmd_buffer[i] = process_str[i];
+				}
+			}
+
+			strip_newline(cmd_buffer);
+			arg_str = strchr(cmd_buffer, ' ');
+			if (arg_str != NULL) {
+				arg_str[0] = '\0';
+				arg_str++;
+			}
+
+			cmd = tri_get_string_autocomplete(&commands, cmd_buffer, &ambiguous);
+
+			if (ambiguous) {
+				printf("ambiguous command: '%s'\n", cmd_buffer);
+				break;
+			} else if (cmd == NULL) {
+				printf("unrecognized command: '%s'\n", cmd_buffer);
+				break;
+			} else {
+				cmd(arg_str);
+			}
+
+			process_str = strchr(process_str, ';');
+			if (process_str != NULL) {
+				process_str++;
+			} else {
+				break;
+			}
+		} while (1);
 	}
 
 	return 0;