diff --git a/programs/README.md b/programs/README.md index 2833875e..22a00409 100644 --- a/programs/README.md +++ b/programs/README.md @@ -185,7 +185,7 @@ version is less than `128 MiB`). Compression Speed vs Ratio | Decompression Speed ---------------------------|--------------------- -![Compression Speed vs Ratio](../doc/images/ldmCspeed.png "Compression Speed vs Ratio") | ![Decompression Speed](../doc/images/ldmDspeed.png "Decompression Speed") +![Compression Speed vs Ratio](https://raw.githubusercontent.com/facebook/zstd/v1.3.3/doc/images/ldmCspeed.png "Compression Speed vs Ratio") | ![Decompression Speed](https://raw.githubusercontent.com/facebook/zstd/v1.3.3/doc/images/ldmDspeed.png "Decompression Speed") | Method | Compression ratio | Compression speed | Decompression speed | |:-------|------------------:|-------------------------:|---------------------------:| @@ -208,10 +208,24 @@ The below table illustrates this on the [Silesia compression corpus]. [Silesia compression corpus]: http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia | Method | Compression ratio | Compression speed | Decompression speed | -|:-------|------------------:|-------------------------:|---------------------------:| -| `zstd -1` | `2.878` | `231.7 MB/s` | `594.4 MB/s` | -| `zstd -1 --long` | `2.929` | `106.5 MB/s` | `517.9 MB/s` | -| `zstd -5` | `3.274` | `77.1 MB/s` | `464.2 MB/s` | -| `zstd -5 --long` | `3.319` | `51.7 MB/s` | `371.9 MB/s` | -| `zstd -10` | `3.523` | `16.4 MB/s` | `489.2 MB/s` | -| `zstd -10 --long`| `3.566` | `16.2 MB/s` | `415.7 MB/s` | +|:-------|------------------:|------------------:|---------------------:| +| `zstd -1` | `2.878` | `231.7 MB/s` | `594.4 MB/s` | +| `zstd -1 --long` | `2.929` | `106.5 MB/s` | `517.9 MB/s` | +| `zstd -5` | `3.274` | `77.1 MB/s` | `464.2 MB/s` | +| `zstd -5 --long` | `3.319` | `51.7 MB/s` | `371.9 MB/s` | +| `zstd -10` | `3.523` | `16.4 MB/s` | `489.2 MB/s` | +| `zstd -10 --long`| `3.566` | `16.2 MB/s` | `415.7 MB/s` | + + +#### zstdgrep + +`zstdgrep` is a utility which makes it possible to `grep` directly a `.zst` compressed file. +It's used the same way as normal `grep`, for example : +`zstdgrep pattern file.zst` + +`zstdgrep` is _not_ compatible with dictionary compression. + +To search into a file compressed with a dictionary, +it's necessary to decompress it using `zstd` or `zstdcat`, +and then pipe the result to `grep`. For example : +`zstdcat -D dictionary -qc -- file.zst | grep pattern`