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Command Line Interface for LZ4 library
============================================
### Build
The Command Line Interface (CLI) can be generated
using the `make` command without any additional parameters.
The `Makefile` script supports all [standard conventions](https://www.gnu.org/prep/standards/html_node/Makefile-Conventions.html),
including standard targets (`all`, `install`, `clean`, etc.)
and standard variables (`CC`, `CFLAGS`, `CPPFLAGS`, etc.).
For advanced use cases, there are targets to different variations of the CLI:
- `lz4` : default CLI, with a command line syntax close to gzip
- `lz4c` : Same as `lz4` with additional support legacy lz4 commands (incompatible with gzip)
- `lz4c32` : Same as `lz4c`, but forced to compile in 32-bits mode
The CLI generates and decodes [LZ4-compressed frames](../doc/lz4_Frame_format.md).
#### Aggregation of parameters
CLI supports aggregation of parameters i.e. `-b1`, `-e18`, and `-i1` can be joined into `-b1e18i1`.
#### Benchmark in Command Line Interface
CLI includes in-memory compression benchmark module for lz4.
The benchmark is conducted using a given filename.
The file is read into memory.
It makes benchmark more precise as it eliminates I/O overhead.
The benchmark measures ratio, compressed size, compression and decompression speed.
One can select compression levels starting from `-b` and ending with `-e`.
The `-i` parameter selects a number of seconds used for each of tested levels.
#### Usage of Command Line Interface
The full list of commands can be obtained with `-h` or `-H` parameter:
```
Usage :
lz4 [arg] [input] [output]
input : a filename
with no FILE, or when FILE is - or stdin, read standard input
Arguments :
-1 : Fast compression (default)
-9 : High compression
-d : decompression (default for .lz4 extension)
-z : force compression
-D FILE: use FILE as dictionary
-f : overwrite output without prompting
-k : preserve source files(s) (default)
--rm : remove source file(s) after successful de/compression
-h/-H : display help/long help and exit
Advanced arguments :
-V : display Version number and exit
-v : verbose mode
-q : suppress warnings; specify twice to suppress errors too
-c : force write to standard output, even if it is the console
-t : test compressed file integrity
-m : multiple input files (implies automatic output filenames)
-r : operate recursively on directories (sets also -m)
-l : compress using Legacy format (Linux kernel compression)
-B# : cut file into blocks of size # bytes [32+]
or predefined block size [4-7] (default: 7)
-BD : Block dependency (improve compression ratio)
-BX : enable block checksum (default:disabled)
--no-frame-crc : disable stream checksum (default:enabled)
--content-size : compressed frame includes original size (default:not present)
--[no-]sparse : sparse mode (default:enabled on file, disabled on stdout)
--favor-decSpeed: compressed files decompress faster, but are less compressed
--fast[=#]: switch to ultra fast compression level (default: 1)
Benchmark arguments :
-b# : benchmark file(s), using # compression level (default : 1)
-e# : test all compression levels from -bX to # (default : 1)
-i# : minimum evaluation time in seconds (default : 3s)```
```
#### License
All files in this directory are licensed under GPL-v2.
See [COPYING](COPYING) for details.
The text of the license is also included at the top of each source file.
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