facebook
/
zstd
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

added mode documentation on ZSTD_CLEVEL 

providing range restriction [1-19] explicitly
partially answering #1829
dev
Yann Collet 2019-10-18 17:22:45 -07:00
parent 8e715d57c5
commit ca73c218be
5 changed files with 22 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
programs/README.md
View File

@ -173,10 +173,13 @@ Benchmark arguments :
```
#### Restricted usage of Environment Variables
Using environment variables to set compression/decompression parameters has security implications. Therefore,
we intentionally restrict its usage. Currently, only `ZSTD_CLEVEL` is supported for setting compression level.
Using environment variables to set parameters has security implications.
Therefore, this avenue is intentionally restricted.
Only `ZSTD_CLEVEL` is supported currently, for setting compression level.
`ZSTD_CLEVEL` can be used to set the level between 1 and 19 (the "normal" range).
If the value of `ZSTD_CLEVEL` is not a valid integer, it will be ignored with a warning message.
Note that command line options will override corresponding environment variable settings.
`ZSTD_CLEVEL` just replaces the default compression level (`3`).
It can be overridden by corresponding command line arguments.
#### Long distance matching mode
The long distance matching mode, enabled with `--long`, is designed to improve

5
programs/zstd.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\.
.

10
programs/zstd.1.md
View File

@ -214,6 +214,16 @@ the last one takes effect.
* `--`:
All arguments after `--` are treated as files
### Restricted usage of Environment Variables
Using environment variables to set parameters has security implications.
Therefore, this avenue is intentionally restricted.
Only `ZSTD_CLEVEL` is supported currently, for setting compression level.
`ZSTD_CLEVEL` can be used to set the level between 1 and 19 (the "normal" range).
If the value of `ZSTD_CLEVEL` is not a valid integer, it will be ignored with a warning message.
`ZSTD_CLEVEL` just replaces the default compression level (`3`).
It can be overridden by corresponding command line arguments.
DICTIONARY BUILDER
------------------

2
programs/zstdgrep.1
View File

@ -1,5 +1,5 @@
.
.TH "ZSTDGREP" "1" "September 2019" "zstd 1.4.4" "User Commands"
.TH "ZSTDGREP" "1" "October 2019" "zstd 1.4.4" "User Commands"
.
.SH "NAME"
\fBzstdgrep\fR \- print lines matching a pattern in zstandard\-compressed files

2
programs/zstdless.1
View File

@ -1,5 +1,5 @@
.
.TH "ZSTDLESS" "1" "September 2019" "zstd 1.4.4" "User Commands"
.TH "ZSTDLESS" "1" "October 2019" "zstd 1.4.4" "User Commands"
.
.SH "NAME"
\fBzstdless\fR \- view zstandard\-compressed files