Add a "git-show-index" helper that shows the contents of a pack index

This was invaluable for debugging the zero-sized compression issue, and
might be useful for scripting too, if people want to see the contents of
a pack.

1 files changed, 28 insertions, 0 deletions

diff --git a/show-index.c b/show-index.c
new file mode 100644
index 0000000000..c21d660b62
--- /dev/null
+++ b/show-index.c
@@ -0,0 +1,28 @@
+#include "cache.h"
+
+int main(int argc, char **argv)
+{
+	int i;
+	unsigned nr;
+	unsigned int entry[6];
+	static unsigned int top_index[256];
+
+	if (fread(top_index, sizeof(top_index), 1, stdin) != 1)
+		die("unable to read idex");
+	nr = 0;
+	for (i = 0; i < 256; i++) {
+		unsigned n = ntohl(top_index[i]);
+		if (n < nr)
+			die("corrupt index file");
+		nr = n;
+	}
+	for (i = 0; i < nr; i++) {
+		unsigned offset;
+
+		if (fread(entry, 24, 1, stdin) != 1)
+			die("unable to read entry %u/%u", i, nr);
+		offset = ntohl(entry[0]);
+		printf("%u %s\n", offset, sha1_to_hex((void *)(entry+1)));
+	}
+	return 0;
+}