Improve error reporting

[oweals/jsonpath.git] / main.c

diff --git a/main.c b/main.c
index 3166746fd985e58623265d8fcafd6041c84b29b8..62e38e941177cc88743be5ade4cf9a7e4ce1fdb2 100644 (file)
--- a/main.c
+++ b/main.c
@@ -250,6 +250,57 @@ match_cb(struct json_object *res, void *priv)
        }
 }
 
+static void
+print_error(struct jp_state *state, char *expr)
+{
+       int i;
+       bool first = true;
+
+       fprintf(stderr, "Syntax error: ");
+
+       switch (state->error_code)
+       {
+       case -4:
+               fprintf(stderr, "Unexpected character\n");
+               break;
+       
+       case -3:
+               fprintf(stderr, "String or label literal too long\n");
+               break;
+
+       case -2:
+               fprintf(stderr, "Invalid escape sequence\n");
+               break;
+
+       case -1:
+               fprintf(stderr, "Unterminated string\n");
+               break;
+
+       default:
+               for (i = 0; i < sizeof(state->error_code) * 8; i++)
+               {
+                       if (state->error_code & (1 << i))
+                       {
+                               fprintf(stderr,
+                                       first ? "Expecting %s" : " or %s", tokennames[i]);
+
+                               first = false;
+                       }
+               }
+
+               fprintf(stderr, "\n");
+               break;
+       }
+
+       fprintf(stderr, "In expression %s\n", expr);
+       fprintf(stderr, "Near here ----");
+
+       for (i = 0; i < state->error_pos; i++)
+               fprintf(stderr, "-");
+
+       fprintf(stderr, "^\n");
+}
+
 static bool
 filter_json(int opt, struct json_object *jsobj, char *expr)
 {
@@ -261,12 +312,14 @@ filter_json(int opt, struct json_object *jsobj, char *expr)
 
        state = jp_parse(expr);
 
-       if (!state || state->error)
+       if (!state)
        {
-               fprintf(stderr, "Syntax error near {%s}: %s\n",
-                       state ? expr + state->erroff : expr,
-                       state ? state->error : "Out of memory");
-
+               fprintf(stderr, "Out of memory\n");
+               goto out;
+       }
+       else if (state->error_code)
+       {
+               print_error(state, expr);
                goto out;
        }