Use standard POSIX "ustar" format for the scratch disk.

[pintos-anon] / src / lib / ustar.h

diff --git a/src/lib/ustar.h b/src/lib/ustar.h
new file mode 100644 (file)
index 0000000..43a5513
--- /dev/null
+++ b/src/lib/ustar.h
@@ -0,0 +1,29 @@
+#ifndef __LIB_USTAR_H
+#define __LIB_USTAR_H
+
+/* Support for the standard Posix "ustar" format.  See the
+   documentation of the "pax" utility in [SUSv3] for the the
+   "ustar" format specification. */
+
+#include <stdbool.h>
+
+/* Type of a file entry in an archive.
+   The values here are the bytes that appear in the file format.
+   Only types of interest to Pintos are listed here. */
+enum ustar_type
+  {
+    USTAR_REGULAR = '0',        /* Ordinary file. */
+    USTAR_DIRECTORY = '5',      /* Directory. */
+    USTAR_EOF = -1              /* End of archive (not an official value). */
+  };
+
+/* Size of a ustar archive header, in bytes. */
+#define USTAR_HEADER_SIZE 512
+
+bool ustar_make_header (const char *file_name, enum ustar_type,
+                        int size, char header[USTAR_HEADER_SIZE]);
+const char *ustar_parse_header (const char header[USTAR_HEADER_SIZE],
+                                const char **file_name,
+                                enum ustar_type *, int *size);
+
+#endif /* lib/ustar.h */