test 4 working+ test scripts nearly setup for tracking

334/homework/msh/msh.c

@@ -21,12 +21,22 @@ void remove_newline(char*);
 void exit_branch(const char*);
 int  builtin_response(char*);
 
-
-int main(void) {
+int main(int argc, char** argv) {
+	FILE* file = NULL;
+	if(argc == 2) {
+		file = fopen(argv[1], "r");
+	}
 	char buffer[MAX_BUF];
 	while(1) {
-		printf("%s", PROMPT);
-		fgets(buffer, MAX_BUF, stdin);
+		// determine if we're reading from stdin or a stream of some sort
+		if(file == NULL && isatty(STDIN_FILENO)) {
+			printf("%s", PROMPT);
+			fgets(buffer, MAX_BUF, stdin);
+		}
+		else {
+			fgets(buffer, MAX_BUF, file);
+		}
+
 		// Deal with EOF input
 		if(!strlen(buffer)) {
 			exit(0);
@@ -109,3 +119,4 @@ int builtin_response(char* buffer) {
 	}
 
 }
+