1 files changed, 25 insertions, 0 deletions
diff --git a/util.c b/util.c
index 5ae208c..dedb9db 100644
--- a/util.c
+++ b/util.c
@@ -950,6 +950,31 @@ int dev_open(char *dev, int flags)
 	return fd;
 }
 
+int dev_open_check(char *devname, int flags)
+{
+	int dfd;
+	struct stat stb;
+
+	dfd = dev_open(devname, flags);
+	if (dfd < 0) {
+		fprintf(stderr, Name ": cannot open %s: %s.\n",
+			devname, strerror(errno));
+		return -1;
+	}
+	if (fstat(dfd, &stb) < 0) {
+		fprintf(stderr, Name ": fstat failed on %s: %s.\n",
+			devname, strerror(errno));
+		close(dfd);
+		return -1;
+	}
+	if ((stb.st_mode & S_IFMT) != S_IFBLK) {
+		fprintf(stderr, Name ": %s is not a block device.\n", devname);
+		close(dfd);
+		return -1;
+	}
+	return dfd;
+}
+
 int open_dev(int devnum)
 {
 	char buf[20];