Initial revision

1 files changed, 42 insertions, 0 deletions

diff --git a/lzw.h b/lzw.h
new file mode 100644
index 0000000..4b7ac86
--- /dev/null
+++ b/lzw.h
@@ -0,0 +1,42 @@
+/* lzw.h -- define the lzw functions.
+ * Copyright (C) 1992-1993 Jean-loup Gailly.
+ * This is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License, see the file COPYING.
+ */
+
+#if !defined(OF) && defined(lint)
+#  include "gzip.h"
+#endif
+
+#ifndef BITS
+#  define BITS 16
+#endif
+#define INIT_BITS 9              /* Initial number of bits per code */
+
+#define	LZW_MAGIC  "\037\235"   /* Magic header for lzw files, 1F 9D */
+
+#define BIT_MASK    0x1f /* Mask for 'number of compression bits' */
+/* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free.
+ * It's a pity that old uncompress does not check bit 0x20. That makes
+ * extension of the format actually undesirable because old compress
+ * would just crash on the new format instead of giving a meaningful
+ * error message. It does check the number of bits, but it's more
+ * helpful to say "unsupported format, get a new version" than
+ * "can only handle 16 bits".
+ */
+
+#define BLOCK_MODE  0x80
+/* Block compression: if table is full and compression rate is dropping,
+ * clear the dictionary.
+ */
+
+#define LZW_RESERVED 0x60 /* reserved bits */
+
+#define	CLEAR  256       /* flush the dictionary */
+#define FIRST  (CLEAR+1) /* first free entry */
+
+extern int maxbits;      /* max bits per code for LZW */
+extern int block_mode;   /* block compress mode -C compatible with 2.0 */
+
+extern int lzw    OF((int in, int out));
+extern int unlzw  OF((int in, int out));