[ndctl PATCH v3 11/21] util/hexdump: Add a util helper to print a buffer in hex

[Vishal Verma <vishal.l.verma@intel.com>]

In preparation for tests that may need to set, retrieve, and display
opaque data, add a hexdump function in util/

Cc: Ben Widawsky <ben.widawsky@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
 util/hexdump.h |  8 ++++++++
 util/hexdump.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+)
 create mode 100644 util/hexdump.h
 create mode 100644 util/hexdump.c

diff --git a/util/hexdump.h b/util/hexdump.h
new file mode 100644
index 0000000..d322b6a
--- /dev/null
+++ b/util/hexdump.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2021 Intel Corporation. All rights reserved. */
+#ifndef _UTIL_HEXDUMP_H_
+#define _UTIL_HEXDUMP_H_
+
+void hex_dump_buf(unsigned char *buf, int size);
+
+#endif /* _UTIL_HEXDUMP_H_*/
diff --git a/util/hexdump.c b/util/hexdump.c
new file mode 100644
index 0000000..1ab0118
--- /dev/null
+++ b/util/hexdump.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2015-2021 Intel Corporation. All rights reserved. */
+#include <stdio.h>
+#include <util/hexdump.h>
+
+static void print_separator(int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		fprintf(stderr, "-");
+	fprintf(stderr, "\n");
+}
+
+void hex_dump_buf(unsigned char *buf, int size)
+{
+	int i;
+	const int grp = 4;  /* Number of bytes in a group */
+	const int wid = 16; /* Bytes per line. Should be a multiple of grp */
+	char ascii[wid + 1];
+
+	/* Generate header */
+	print_separator((wid * 4) + (wid / grp) + 12);
+
+	fprintf(stderr, "Offset    ");
+	for (i = 0; i < wid; i++) {
+		if (i % grp == 0) fprintf(stderr, " ");
+		fprintf(stderr, "%02x ", i);
+	}
+	fprintf(stderr, "  Ascii\n");
+
+	print_separator((wid * 4) + (wid / grp) + 12);
+
+	/* Generate hex dump */
+	for (i = 0; i < size; i++) {
+		if (i % wid == 0) fprintf(stderr, "%08x  ", i);
+		ascii[i % wid] =
+		    ((buf[i] >= ' ') && (buf[i] <= '~')) ? buf[i] : '.';
+		if (i % grp == 0) fprintf(stderr, " ");
+		fprintf(stderr, "%02x ", buf[i]);
+		if ((i == size - 1) && (size % wid != 0)) {
+			int j;
+			int done = size % wid;
+			int grps_done = (done / grp) + ((done % grp) ? 1 : 0);
+			int spaces = wid / grp - grps_done + ((wid - done) * 3);
+
+			for (j = 0; j < spaces; j++) fprintf(stderr, " ");
+		}
+		if ((i % wid == wid - 1) || (i == size - 1))
+			fprintf(stderr, "  %.*s\n", (i % wid) + 1, ascii);
+	}
+	print_separator((wid * 4) + (wid / grp) + 12);
+}
-- 
2.31.1