ddidderr/zstd-rs
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

added mode documentation on ZSTD_CLEVEL

Browse Source 
providing range restriction [1-19] explicitly
partially answering #1829
This commit is contained in:
Yann Collet
2019-10-18 17:22:45 -07:00
parent 8e715d57c5
commit ca73c218be
5 changed files with 22 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files
programs/zstd.1
+4 -1
View File
@@ -1,5 +1,5 @@
.
.TH "ZSTD" "1" "September 2019" "zstd 1.4.4" "User Commands"
.TH "ZSTD" "1" "October 2019" "zstd 1.4.4" "User Commands"
.
.SH "NAME"
\fBzstd\fR \- zstd, zstdmt, unzstd, zstdcat \- Compress or decompress \.zst files
@@ -206,6 +206,9 @@ add integrity check computed from uncompressed data (default: enabled)
\fB\-\-\fR
All arguments after \fB\-\-\fR are treated as files
.
.SS "Restricted usage of Environment Variables"
Using environment variables to set parameters has security implications\. Therefore, this avenue is intentionally restricted\. Only \fBZSTD_CLEVEL\fR is supported currently, for setting compression level\. \fBZSTD_CLEVEL\fR can be used to set the level between 1 and 19 (the "normal" range)\. If the value of \fBZSTD_CLEVEL\fR is not a valid integer, it will be ignored with a warning message\. \fBZSTD_CLEVEL\fR just replaces the default compression level (\fB3\fR)\. It can be overridden by corresponding command line arguments\.
.
.SH "DICTIONARY BUILDER"
\fBzstd\fR offers \fIdictionary\fR compression, which greatly improves efficiency on small files and messages\. It\'s possible to train \fBzstd\fR with a set of samples, the result of which is saved into a file called a \fBdictionary\fR\. Then during compression and decompression, reference the same dictionary, using command \fB\-D dictionaryFileName\fR\. Compression of small files similar to the sample set will be greatly improved\.
.