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-rw-r--r--README23
1 files changed, 14 insertions, 9 deletions
diff --git a/README b/README
index 98f4efb..675b494 100644
--- a/README
+++ b/README
@@ -6,6 +6,10 @@ gzip or bzip2. Lzip decompresses almost as fast as gzip and compresses
better than bzip2, which makes it well suited for software distribution
and data archiving.
+Lzip uses the same well-defined exit status values used by bzip2, which
+makes it safer when used in pipes or scripts than compressors returning
+ambiguous warning values, like gzip.
+
If you ever need to recover data from a damaged lzip file, try the
lziprecover program.
@@ -42,15 +46,16 @@ memory requirement is affected at compression time by the choice of
dictionary size limit.
As a self-check for your protection, lzip stores in the member trailer
-the 32-bit CRC of the original data and the size of the original data,
-to make sure that the decompressed version of the data is identical to
-the original. This guards against corruption of the compressed data, and
-against undetected bugs in lzip (hopefully very unlikely). The chances
-of data corruption going undetected are microscopic, less than one
-chance in 4000 million for each member processed. Be aware, though, that
-the check occurs upon decompression, so it can only tell you that
-something is wrong. It can't help you recover the original uncompressed
-data.
+the 32-bit CRC of the original data, the size of the original data and
+the size of the member. These values, together with the value remaining
+in the range decoder and the end-of-stream marker, provide a very safe 4
+factor integrity checking which guarantees that the decompressed version
+of the data is identical to the original. This guards against corruption
+of the compressed data, and against undetected bugs in lzip (hopefully
+very unlikely). The chances of data corruption going undetected are
+microscopic. Be aware, though, that the check occurs upon decompression,
+so it can only tell you that something is wrong. It can't help you
+recover the original uncompressed data.
Lzip implements a simplified version of the LZMA (Lempel-Ziv-Markov
chain-Algorithm) algorithm. The high compression of LZMA comes from