Only optionally show non-differing 16-byte blocks

1 files changed, 6 insertions, 0 deletions

diff --git a/hexdiff.c b/hexdiff.c
index da9a9d8..d2a8bbb 100644
--- a/hexdiff.c
+++ b/hexdiff.c
@@ -35,6 +35,7 @@ static const int diff_gradient[256] = {
 
 static bool use_color = true;
 static bool has_color = false;
+static bool show_all = false;
 
 static inline void
 color_byte(struct file *cur, struct file *other, size_t i)
@@ -67,6 +68,8 @@ main(int argc, const char **argv)
 			use_color = true;
 		} else if (!strcmp(*arg, "-C")) {
 			use_color = false;
+		} else if (!strcmp(*arg, "-a")) {
+			show_all = true;
 		} else if (!f1.fname) {
 			f1.fname = *arg;
 		} else if (!f2.fname) {
@@ -91,6 +94,9 @@ main(int argc, const char **argv)
 	while (!feof(f1.file) && !feof(f2.file)) {
 		f1.buflen = fread(f1.buf, 1, 16, f1.file);
 		f2.buflen = fread(f2.buf, 1, 16, f2.file);
+		if (!show_all && f1.buflen == f2.buflen
+				&& !memcmp(f1.buf, f2.buf, f1.buflen))
+			continue;
 		if (!f1.buflen && !f2.buflen) break;
 
 		printf("%06lx: ", pos);