Lines Matching refs:is
9 `zstdmt` is equivalent to `zstd -T0`
11 `unzstd` is equivalent to `zstd -d`
13 `zstdcat` is equivalent to `zstd -dcf`
18 `zstd` is a fast lossless compression algorithm and data compression tool,
20 It is based on the **LZ77** family, with further FSE & huff0 entropy stages.
26 `zstd` command line syntax is generally similar to gzip,
36 - `zstd` displays a short help page when command line is an error.
41 If no _files_ are given or _file_ is `-`, `zstd` reads from standard input
44 if it is a terminal : it will display an error message and skip the _file_.
46 if it is a terminal.
48 Unless `--stdout` or `-o` is specified, _files_ are written to a new file
49 whose name is derived from the source _file_ name:
51 * When compressing, the suffix `.zst` is appended to the source filename to
53 * When decompressing, the `.zst` suffix is removed from the source filename to
57 It is possible to concatenate `.zst` files as is.
64 In most places where an integer argument is expected,
65 an optional suffix is supported to easily indicate large integers.
81 This is the default operation mode when no operation mode option is specified
82 and no other operation mode is implied from the command name
88 This option is equivalent to `--decompress --stdout` except that the
89 decompressed data is discarded instead of being written to standard output.
110 If `=#` is not present, it defaults to `1`.
114 Similarly, if a compression level is set after `--fast`, it overrides it.
117 If `#` is 0, attempt to detect and use the number of physical CPU cores.
118 In all cases, the nb of threads is capped to ZSTDMT_NBWORKERS_MAX==200.
119 This modifier does nothing if `zstd` is compiled without multithread support.
122 In this mode, compression is serialized with I/O, which is slightly slower.
123 (This is different from `-T1`, which spawns 1 compression thread in parallel of I/O).
124 This mode is the only one available when multithread support is disabled.
126 Final compressed result is slightly different from `-T1`.
134 Due to the chaotic nature of dynamic adaptation, compressed result is not reproducible.
138 enables long distance matching with `#` `windowLog`, if not `#` is not
142 This setting is designed to improve the compression ratio for files with
145 Note: If `windowLog` is set to larger than 27, `--long=windowLog` or
151 This is effectively dictionary compression with some convenient parameter
165 compressed file more rsync-friendly. There is a negligible impact to
174 enable / disable whether or not the original size of the file is placed in
175 the header of the compressed file. The default option is
183 as the maximum amount of memory the decompressor is allowed to use, but you can
187 This is also used during compression when using with --patch-from=. In this case,
196 will be when optimizing compression parameters. If the stream size is relatively
206 force write to standard output, even if it is the console
212 default: enabled when output is into a file,
213 and disabled when output is stdout.
217 …-o, will trigger a confirmation prompt (which can be silenced with -f), as this is a destructive o…
220 This is the default behavior.
225 Format is compatible with `ls` output, with one file per line.
239 If input directory is an absolute directory (i.e. "/var/tmp/abc"),
247 If no such format is provided, `zstd` is the default.
264 particular src file. If the provided src file is not a regular file
266 That is, the parameters that are used when the src size is unknown.
273 Therefore, this avenue is intentionally restricted.
278 If the value of `ZSTD_CLEVEL` is not a valid integer, it will be ignored with a warning message.
282 If the value of `ZSTD_NBTHREADS` is not a valid unsigned integer, it will be ignored with a warning…
283 'ZSTD_NBTHREADS` has a default value of (`1`), and is capped at ZSTDMT_NBWORKERS_MAX==200. `zstd` m…
295 the result of which is saved into a file called a `dictionary`.
306 Supports multithreading if `zstd` is compiled with threading support.
322 A dictionary ID is a locally unique ID that a decoder can use to verify it is
333 If _d_ is not specified, then it tries _d_ = 6 and _d_ = 8.
334 If _k_ is not specified, then it tries _steps_ values in the range [50, 2000].
335 If _steps_ is not specified, then the default value of 40 is used.
336 If _split_ is not specified or split <= 0, then the default value of 100 is used.
338 If _shrink_ flag is not used, then the default value for _shrinkDict_ of 0 is used.
339 If _shrink_ is not specified, then the default value for _shrinkDictMaxRegression_ of 1 is used.
342 The score of a segment is computed by the sum of the frequencies of all the
346 Good values for _k_ vary widely based on the input data, but a safe range is
348 If _split_ is 100, all input samples are used for both training and testing
350 Supports multithreading if `zstd` is compiled with threading support.
352 in size until compression ratio of the truncated dictionary is at most
373 If _split_ is not specified, then it tries _split_ = 75.
374 If _f_ is not specified, then it tries _f_ = 20.
376 If _accel_ is not specified, then it tries _accel_ = 1.
380 _f_ is log of size of array that keeps track of frequency of subsegments of size _d_.
381 The subsegment is hashed to an index in the range [0,2^_f_ - 1].
382 …It is possible that 2 different subsegments are hashed to the same index, and they are considered …
396 `--train-legacy=s=#` is also accepted.
421 **Methodology:** For both compression and decompression speed, the entire input is compressed/decom…
448 The minimum _wlog_ is 10 (1 KiB) and the maximum is 30 (1 GiB) on 32-bit
451 Note: If `windowLog` is set to larger than 27, `--long=windowLog` or
460 The minimum _hlog_ is 6 (64 B) and the maximum is 30 (1 GiB).
469 This option is ignored for the ZSTD_fast strategy.
471 The minimum _clog_ is 6 (64 B) and the maximum is 29 (524 Mib) on 32-bit platforms
481 The minimum _slog_ is 1 and the maximum is 'windowLog' - 1.
489 The minimum _mml_ is 3 and the maximum is 7.
501 Impact is reversed : a larger `targetLength` increases compression speed
506 The minimum _tlen_ is 0 and the maximum is 128 Kib.
510 This parameter is only available when multithreading is enabled.
513 The minimum _ovlog_ is 0, and the maximum is 9.
515 9 means "full overlap", meaning up to `windowSize` is reloaded from previous job.
518 Value 0 is special and means "default" : _ovlog_ is automatically determined by `zstd`.
524 This option is ignored unless long distance matching is enabled.
529 The minimum _lhlog_ is 6 and the maximum is 30 (default: 20).
534 This option is ignored unless long distance matching is enabled.
538 The minimum _lmml_ is 4 and the maximum is 4096 (default: 64).
544 This option is ignored unless long distance matching is enabled.
549 The minimum _lblog_ is 1 and the maximum is 8 (default: 3).
555 This option is ignored unless long distance matching is enabled.
560 The default value is `wlog - lhlog`.
570 This parameter is available only when multi-threading is enabled.
571 Default value is `4 * windowSize`, which means it varies depending on compression level.
573 Note that job size must respect a minimum value which is enforced transparently.
574 This minimum is either 1 MB, or `overlapSize`, whichever is largest.