1 files changed, 25 insertions, 0 deletions
diff --git a/io.c b/io.c
new file mode 100644
index 0000000..6ee9e29
--- /dev/null
+++ b/io.c
@@ -0,0 +1,25 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+off_t
+filesize(int fd, const char *fname)
+{
+	struct stat st;
+
+	if (fstat(fd, &st))
+		eprintf("fstat %s:", fname);
+
+	switch (st.st_mode & S_IFMT) {
+	case S_IFREG:
+		break;
+	case S_IFBLK:
+		if (ioctl(fd, BLKGETSIZE64, &st.st_size) < 0)
+			eprintf("ioctl %s BLKGETSIZE64:", fname);
+		break;
+	default:
+		eprintf("%s: not a regular file or block device", fname);
+	}
+
+	return st.st_size;
+}