From b775c0e501df5e7c0a340bfb67a2f4a8646ea0de Mon Sep 17 00:00:00 2001
From: Brad Grantham <grantham@plunk.org>
Date: Thu, 31 Dec 2020 11:07:16 -0800
Subject: [PATCH] add crude tool for enormous line-by-line diffs

---
 dumpdiffs.cpp | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 dumpdiffs.cpp

diff --git a/dumpdiffs.cpp b/dumpdiffs.cpp
new file mode 100644
index 0000000..8f68c0d
--- /dev/null
+++ b/dumpdiffs.cpp
@@ -0,0 +1,51 @@
+#include <cstdio>
+#include <cstring>
+#include <algorithm>
+
+int main(int argc, char **argv)
+{
+    FILE *dump1 = fopen(argv[1], "r");
+    FILE *dump2 = fopen(argv[2], "r");
+
+    int fieldSize = std::max(strlen(argv[1]), strlen(argv[2]));
+
+    char line1[512];
+    char line2[512];
+
+    time_t then = time(0);
+    int linecount = 0;
+    size_t bytecount = 0;
+
+    unsigned int clockhigh = 0;
+    unsigned int clocklow = 0;
+
+    while(fgets(line1, sizeof(line1) - 1, dump1)) {
+        bytecount += strlen(line1);
+        line1[strlen(line1) - 1] = '\0';
+
+        if(strncmp(line1, "clock", 5) == 0) {
+            if(sscanf(line1, "clock = %u, %u", &clockhigh, &clocklow) != 2) {
+                printf("Failed to read clock values\n");
+                exit(1);
+            }
+        }
+
+        fgets(line2, sizeof(line2) - 1, dump2);
+        line2[strlen(line2) - 1] = '\0';
+
+        if(strcmp(line1, line2) != 0) {
+            printf("line %d differed; clock %u, %u\n", linecount, clockhigh, clocklow);
+            printf("    %*s : %s\n", fieldSize, argv[1], line1);
+            printf("    %*s : %s\n", fieldSize, argv[2], line2);
+            exit(1);
+        }
+
+        time_t now = time(0);
+        if(now > then) {
+            then = now;
+            printf("byte %zd, clock %u, %u\n", bytecount, clockhigh, clocklow); 
+        }
+
+        linecount++;
+    }
+}