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-rw-r--r--README38
1 files changed, 25 insertions, 13 deletions
diff --git a/README b/README
index 7a02327..e89b25f 100644
--- a/README
+++ b/README
@@ -6,12 +6,9 @@ the one of lzip, bzip2 or gzip.
Plzip can compress/decompress large files on multiprocessor machines
much faster than lzip, at the cost of a slightly reduced compression
-ratio. On files large enough (several GB), plzip can use hundreds of
-processors. On files of only a few MB it is better to use lzip.
-
-Plzip uses the same well-defined exit status values used by lzip and
-bzip2, which makes it safer when used in pipes or scripts than
-compressors returning ambiguous warning values, like gzip.
+ratio. Note that the number of usable threads is limited by file size,
+so on files larger than a few GB plzip can use hundreds of processors,
+but on files of only a few MB plzip is no faster than lzip.
Plzip uses the lzip file format; the files produced by plzip are fully
compatible with lzip-1.4 or newer, and can be rescued with lziprecover.
@@ -35,12 +32,27 @@ lziprecover program. Lziprecover makes lzip files resistant to bit-flip
recovery capabilities, including error-checked merging of damaged copies
of a file.
-Plzip replaces every file given in the command line with a compressed
-version of itself, with the name "original_name.lz". Each compressed
-file has the same modification date, permissions, and, when possible,
-ownership as the corresponding original, so that these properties can be
-correctly restored at decompression time. Plzip is able to read from some
-types of non regular files if the "--stdout" option is specified.
+Plzip uses the same well-defined exit status values used by lzip and
+bzip2, which makes it safer than compressors returning ambiguous warning
+values (like gzip) when it is used as a back end for tar or zutils.
+
+When compressing, plzip replaces every file given in the command line
+with a compressed version of itself, with the name "original_name.lz".
+When decompressing, plzip attempts to guess the name for the decompressed
+file from that of the compressed file as follows:
+
+filename.lz becomes filename
+filename.tlz becomes filename.tar
+anyothername becomes anyothername.out
+
+(De)compressing a file is much like copying or moving it; therefore plzip
+preserves the access and modification dates, permissions, and, when
+possible, ownership of the file just as "cp -p" does. (If the user ID or
+the group ID can't be duplicated, the file permission bits S_ISUID and
+S_ISGID are cleared).
+
+Plzip is able to read from some types of non regular files if the
+"--stdout" option is specified.
If no file names are specified, plzip compresses (or decompresses) from
standard input to standard output. In this case, plzip will decline to
@@ -53,7 +65,7 @@ corresponding uncompressed files. Integrity testing of concatenated
compressed files is also supported.
-Copyright (C) 2009, 2010, 2011, 2012, 2013 Antonio Diaz Diaz.
+Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014 Antonio Diaz Diaz.
This file is free documentation: you have unlimited permission to copy,
distribute and modify it.