1 files changed, 66 insertions, 0 deletions
diff --git a/blkid.c b/blkid.c
new file mode 100644
index 0000000..f88290d
--- /dev/null
+++ b/blkid.c
@@ -0,0 +1,66 @@
+/*
+ * Print an MBR disk signature for use in a Linux PARTUUID
+ *
+ * Copyright (C) 2020  Patrick McDermott
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static int
+read_id(const char *dev)
+{
+	FILE *fp;
+	uint8_t id[4];
+
+	if ((fp = fopen(dev, "r")) == NULL) {
+		perror("Failed to open device");
+		return 1;
+	}
+
+	if (fseek(fp, 440L, SEEK_SET) != 0) {
+		perror("Failed to seek on device");
+		fclose(fp);
+		return 1;
+	}
+
+	if (fread(id, sizeof(*id), sizeof(id) / sizeof(*id), fp) != 4) {
+		perror("Failed to read from device");
+		fclose(fp);
+		return 1;
+	}
+
+	printf("%" PRIx8 "%" PRIx8 "%" PRIx8 "%" PRIx8 "\n",
+			id[3], id[2], id[1], id[0]);
+
+	fclose(fp);
+	return 0;
+}
+
+int
+main(int argc, char *argv[])
+{
+	int errors = 0;
+
+	while (--argc) {
+		errors += read_id(*++argv);
+	}
+
+	return (errors > 0) ? EXIT_FAILURE : EXIT_SUCCESS;
+}