Store number of intermediate chars explicitly, instead of relying on null-terminated string.

Also, report errors by signaling an error action to the callback instead of doing a cheesy
fprintf() to stderr.

Author: Joshua Haberman

vtparse.c

@@ -6,19 +6,15 @@
  * This code is in the public domain.
  */
 
-#include <string.h>
-#include <stdlib.h>
-#include <stdio.h>
-
 #include "vtparse.h"
 
 void vtparse_init(vtparse_t *parser, vtparse_callback_t cb)
 {
-    parser->state                 = VTPARSE_STATE_GROUND;
-    parser->intermediate_chars[0] = '\0';
-    parser->num_params            = 0;
-    parser->ignore_flagged        = 0;
-    parser->cb                    = cb;
+    parser->state                  = VTPARSE_STATE_GROUND;
+    parser->num_intermediate_chars = 0;
+    parser->num_params             = 0;
+    parser->ignore_flagged         = 0;
+    parser->cb                     = cb;
 }
 
 static void do_action(vtparse_t *parser, vtparse_action_t action, char ch)
@@ -47,12 +43,10 @@ static void do_action(vtparse_t *parser, vtparse_action_t action, char ch)
         case VTPARSE_ACTION_COLLECT:
         {
             /* Append the character to the intermediate params */
-            int num_intermediate_chars = strlen((char*)parser->intermediate_chars);
-
-            if(num_intermediate_chars + 1 > MAX_INTERMEDIATE_CHARS)
+            if(parser->num_intermediate_chars + 1 > MAX_INTERMEDIATE_CHARS)
                 parser->ignore_flagged = 1;
             else
-                parser->intermediate_chars[num_intermediate_chars++] = ch;
+                parser->intermediate_chars[parser->num_intermediate_chars++] = ch;
 
             break;
         }
@@ -85,13 +79,13 @@ static void do_action(vtparse_t *parser, vtparse_action_t action, char ch)
         }
 
         case VTPARSE_ACTION_CLEAR:
-            parser->intermediate_chars[0] = '\0';
+            parser->num_intermediate_chars = 0;
             parser->num_params            = 0;
             parser->ignore_flagged        = 0;
             break;
 
         default:
-            fprintf(stderr, "Internal error, unknown action %d", action);
+            parser->cb(parser, VTPARSE_ACTION_ERROR, 0);
     }
 }
 

vtparse.h

@@ -20,6 +20,7 @@ typedef struct vtparse {
     vtparse_state_t    state;
     vtparse_callback_t cb;
     unsigned char      intermediate_chars[MAX_INTERMEDIATE_CHARS+1];
+    int                num_intermediate_chars;
     char               ignore_flagged;
     int                params[16];
     int                num_params;

vtparse_tables.rb

@@ -213,7 +213,7 @@ def transition_to(state)
 
 # establish an ordering to the states and actions
 
-$actions_in_order = action_names.keys.sort { |a1, a2| a1.to_s <=> a2.to_s }
+$actions_in_order = action_names.keys.sort { |a1, a2| a1.to_s <=> a2.to_s } + [:error]
 $states_in_order = $states.keys.sort       { |s1, s2| s1.to_s <=> s2.to_s }
 
 #

vtparse_test.c

@@ -7,17 +7,29 @@
  */
 
 #include <stdio.h>
+#include <unistd.h>
 #include "vtparse.h"
 
 void parser_callback(vtparse_t *parser, vtparse_action_t action, unsigned char ch)
 {
     int i;
 
-    printf("Received action %s, char=0x%02x\n", ACTION_NAMES[action]);
-    printf("Intermediate chars: '%s'\n", parser->intermediate_chars);
-    printf("%d Parameters:\n", parser->num_params);
-    for(i = 0; i < parser->num_params; i++)
-        printf("\t%d\n", parser->params[i]);
+    printf("Received action %s\n", ACTION_NAMES[action]);
+    if(ch != 0) printf("Char: 0x%02x ('%c')\n", ch, ch);
+    if(parser->num_intermediate_chars > 0)
+    {
+        printf("%d Intermediate chars:\n", parser->num_intermediate_chars);
+        for(i = 0; i < parser->num_intermediate_chars; i++)
+            printf("  0x%02x ('%c')\n", parser->intermediate_chars[i],
+                                        parser->intermediate_chars[i]);
+    }
+    if(parser->num_params > 0)
+    {
+        printf("%d Parameters:\n", parser->num_params);
+        for(i = 0; i < parser->num_params; i++)
+            printf("\t%d\n", parser->params[i]);
+    }
+
     printf("\n");
 }
 
@@ -29,9 +41,11 @@ int main()
 
     vtparse_init(&parser, parser_callback);
 
-    while(1) {
-        bytes = read(0, buf, 1024);
+    do {
+        bytes = read(STDIN_FILENO, buf, 1024);
         vtparse(&parser, buf, bytes);
-    }
+    } while(bytes > 0);
+
+    return 0;
 }