t/helper/hexdump: add helper to print hexdump of stdin

Co-authored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/t/helper/test-hexdump.c b/t/helper/test-hexdump.c
new file mode 100644
index 0000000000..811e89c1bc
--- /dev/null
+++ b/t/helper/test-hexdump.c
@@ -0,0 +1,30 @@
+#include "test-tool.h"
+#include "git-compat-util.h"
+
+/*
+ * Read stdin and print a hexdump to stdout.
+ */
+int cmd__hexdump(int argc, const char **argv)
+{
+	char buf[1024];
+	ssize_t i, len;
+	int have_data = 0;
+
+	for (;;) {
+		len = xread(0, buf, sizeof(buf));
+		if (len < 0)
+			die_errno("failure reading stdin");
+		if (!len)
+			break;
+
+		have_data = 1;
+
+		for (i = 0; i < len; i++)
+			printf("%02x ", (unsigned char)buf[i]);
+	}
+
+	if (have_data)
+		putchar('\n');
+
+	return 0;
+}