added -help functionality

runner.c

@@ -6,10 +6,15 @@ int main(int argc, char *argv[]) {
     int token;
     FILE *output;
 
-    if (argc == 1 || argc > 3 || (argc == 2 && is_alpha_file(argv[1], strlen(argv[1])) != 0)) {
+    if (argc == 1 || argc > 3) {
         fprintf(stderr, "invalid input with 1, >3, or non .alpha arg \n");
         return -1; //no alpha file or too many args
     } else if (argc == 2) {
+        if (is_help(argv[1])) {
+            return 0;
+        } else if (is_alpha_file(argv[1], strlen(argv[1])) != 0) {
+            return -1;
+        }
         arg = NO_ARG;   //no argument but valid input
         yyin = fopen(argv[1], "r");
     } else {
@@ -48,6 +53,14 @@ int main(int argc, char *argv[]) {
     return 0;
 }
 
+bool is_help(char * input) {
+    if (strcmp(input, "-help") == 0) {
+        printf("HELP:\nHow to run the alpha compiler:\n./alpha [options] program\nValid options:\n-tok output the token number, token, line number, and column number for each of the tokens to the .tok file\n");
+        return true;
+    }
+    return false;
+}
+
 char *is_tok(int argc, char *argv[]) {
     if (argc == 3 && strcmp("-tok", argv[1]) == 0) {
         char *input_prog = argv[2];

runner.h

@@ -15,6 +15,7 @@
 #include <stdlib.h>
 #include "flex.h"
 #include "typedefs.h"
+#include <stdbool.h>
 
 extern int line_number, column_number;
 extern char *yytext;
@@ -24,3 +25,4 @@ int arg;
 int main(int argc, char* argv[]);
 char *is_tok(int argc, char* argv[]);
 int is_alpha_file(char *file, int file_len);
+bool is_help(char * input);