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Crunch Command Line Reference

Complete command-line reference for the crunch data compression tool.

Synopsis

crunch [OPTIONS] -c <CRUNCHER>

Global Options

-c, --cruncher <CRUNCHER>

Required. Specifies the compression algorithm to use.

Choices: - apultra - APultra compression - exomizer - Exomizer compression - lz4 - LZ4 compression - lz48 - LZ48 compression - lz49 - LZ49 compression - lzsa1 - LZSA version 1 - lzsa2 - LZSA version 2 - shrinkler - Shrinkler compression - upkr - UPKR compression - zx0 - ZX0 compression

Example: 

crunch -c apultra -i input.bin -o output.crunched

Input/Output Options

-i, --input <INPUT>

Specifies the input file to compress.

Formats: - Simple binary: data.bin - Amsdos file: SCREEN.BIN - File in disc: game.dsk#LEVEL1.BIN

Example: 

crunch -c exomizer -i sprite.bin -o sprite.crunched

-o, --output <OUTPUT>

Specifies the compressed output file. Requires --input to be specified.

Formats: - Simple binary: data.crunched - Amsdos file: DATA.CRN - File in disc: game.dsk#DATA.CRN

Example: 

crunch -c zx0 -i data.bin -o game.dsk#DATA.CRN

Header Options

-k, --keep-header

Compress the Amsdos header along with the file data.

By default, Amsdos headers are stripped before compression. Use this flag when the header contains important data that should be compressed.

Default: false

Example: 

crunch -c apultra -i FILE.BIN -o FILE.CRN -k

-H, --header

Add an Amsdos header when storing the compressed file on the host.

Default: false

Example: 

crunch -c lzsa1 -i data.bin -o DATA.CRN -H

Source Code Options

-z, --z80

Display the Z80 assembly decompression source code for the selected algorithm.

Cannot be used with --input. This option outputs the decompressor routine that you can include in your Z80 assembly projects.

Conflicts with: --input

Default: false

Example: 

crunch -c apultra -z > unaplib.asm

Common Usage Patterns

Compress a Binary File

crunch -c apultra -i data.bin -o data.crunched

Compress with Amsdos Header

crunch -c exomizer -i graphics.bin -o GRAPHICS.CRN -H

Compress File Preserving Original Header

crunch -c lzsa2 -i MUSIC.BIN -o MUSIC.CRN -k

Compress into Disc Image

crunch -c zx0 -i level1.bin -o game.dsk#LEVEL1.CRN

Extract Decompression Routine

crunch -c apultra -z

Compare Algorithms

Test different algorithms to find the best one for your data:

crunch -c apultra -i data.bin -o data.apultra
crunch -c zx0 -i data.bin -o data.zx0
crunch -c shrinkler -i data.bin -o data.shrink

Then compare file sizes to choose the most effective algorithm.

Exit Status

  • 0 - Success
  • Non-zero - Error occurred (invalid arguments, compression failed, file I/O error)

Notes

  • The --cruncher option is always required
  • Use --z80 to get the decompression routine for your assembly projects
  • Files in disc images use the format disc.dsk#FILE.BIN
  • Amsdos headers are automatically detected and handled by default
  • The --keep-header flag is useful when headers contain data beyond standard metadata

See Also