CHM Commands

Purpose

Complete command-line reference for all CHM (Microsoft Compiled HTML Help) format operations. This document provides detailed syntax, options, and examples for the 4 CHM commands.

References

Getting Started Guide
CHM Format Guide
Ruby API Reference

Concepts

CHM commands follow the pattern: cabriolet COMMAND [OPTIONS] FILE [ARGS]. Each command operates on CHM (Compiled HTML Help) files for listing, extracting, creating, and getting information.

Command Overview

Command	Purpose
chm-list	List contents of a CHM file
chm-extract	Extract files from a CHM archive
chm-info	Display detailed CHM information
chm-create	Create new CHM file

Command

Purpose

chm-list

List contents of a CHM file

chm-extract

Extract files from a CHM archive

chm-info

Display detailed CHM information

chm-create

Create new CHM file

chm-list - List CHM Contents

Display files contained in a CHM archive without extracting them.

Syntax

cabriolet chm-list [OPTIONS] FILE

Parameters

FILE: (required) Path to the CHM file to list

Options

--verbose, -v: Show detailed file information including section and size

Returns

Exit code 0 on success
Exit code 1 on error
Exit code 3 if file not found

Description

The chm-list command displays all files contained in a CHM archive, showing file names, sizes, and which section (compressed or uncompressed) they are stored in.

Examples

Basic listing

cabriolet chm-list help.chm

Output

CHM File: help.chm
Version: 3
Language: 1033
Chunks: 512, Chunk Size: 4096

Files:
  /index.html (15,234 bytes, MSCompressed)
  /style.css (2,048 bytes, MSCompressed)
  /images/logo.png (8,192 bytes, Uncompressed)
  /#SYSTEM (512 bytes, Uncompressed)

Total: 4 files

Verbose listing

cabriolet chm-list --verbose help.chm

Output

CHM File: help.chm
Version: 3
Language: 1033
Chunks: 512
Chunk Size: 4096
Directory offset: 8192
First PMGL: 0
Last PMGL: 15

Files:
  /index.html
    Size: 15,234 bytes
    Section: 1 (MSCompressed)

  /style.css
    Size: 2,048 bytes
    Section: 1 (MSCompressed)

  /images/logo.png
    Size: 8,192 bytes
    Section: 0 (Uncompressed)

  /#SYSTEM
    Size: 512 bytes
    Section: 0 (Uncompressed)
    System file

Total: 4 files
Compressed files: 2
Uncompressed files: 2

Common Errors

File not found: Verify the CHM file path is correct
Invalid CHM signature: File is not a valid CHM archive
Permission denied: Ensure read permissions on the CHM file

chm-extract - Extract CHM Files

Extract all files from a CHM archive to a directory.

Syntax

cabriolet chm-extract [OPTIONS] FILE [OUTPUT_DIR]

Parameters

FILE: (required) Path to the CHM file to extract
OUTPUT_DIR: (optional) Directory to extract files to (default: current directory)

Options

--output, -o: Output directory (alternative to positional argument)
--verbose, -v: Show extraction progress for each file

Returns

Exit code 0 on success
Exit code 1 on error
Exit code 3 if file not found
Exit code 4 if permission denied

Description

The chm-extract command extracts all files from a CHM archive, recreating the directory structure as stored in the CHM. System files (starting with /) are also extracted.

Examples

Extract to current directory

cabriolet chm-extract help.chm

Extract to specific directory

cabriolet chm-extract help.chm output/

Output

Extracted 15 file(s) to output/

Extract with verbose output

cabriolet chm-extract --verbose help.chm extracted/

Output

Opening help.chm...
Version: 3
Language: 1033
Files: 15

Extracting to extracted/
  /index.html (15,234 bytes)... OK
  /style.css (2,048 bytes)... OK
  /images/logo.png (8,192 bytes)... OK
  /images/icon.gif (1,024 bytes)... OK
  /#SYSTEM (512 bytes)... OK
  ...

Extraction complete
Total: 15 files extracted

Using output option

cabriolet chm-extract -o docs/ help.chm

Common Errors

Cannot create output directory: Verify write permissions
Disk full: Ensure sufficient disk space for extraction
LZX decompression failed: CHM compressed section is corrupted
Invalid directory chunk: CHM directory structure is damaged

chm-info - Show CHM Information

Display detailed information about a CHM archive including structure, sections, and files.

Syntax

cabriolet chm-info [OPTIONS] FILE

Parameters

FILE: (required) Path to the CHM file to analyze

Options

--verbose, -v: Show additional technical details

Returns

Exit code 0 on success
Exit code 1 on error
Exit code 3 if file not found

Description

The chm-info command provides comprehensive information about a CHM archive, including version, language, directory structure, sections, and file listings.

Examples

Basic information

cabriolet chm-info help.chm

Output

CHM File Information
==================================================
Filename: help.chm
Version: 3
Language ID: 1033
Timestamp: 2024-01-15 14:30:00
Size: 524,288 bytes

Directory:
  Offset: 8192
  Chunks: 512
  Chunk Size: 4096
  First PMGL: 0
  Last PMGL: 15

Sections:
  Section 0 (Uncompressed): offset 2048
  Section 1 (MSCompressed): LZX compression

Files: 15 regular, 3 system

Regular Files:
  /index.html
    Size: 15,234 bytes (Sec1)
  /style.css
    Size: 2,048 bytes (Sec1)
  /images/logo.png
    Size: 8,192 bytes (Sec0)

Verbose information

cabriolet chm-info --verbose help.chm

Output

CHM File Information
==================================================
Filename: help.chm
Version: 3
Language ID: 1033 (English - United States)
Timestamp: 2024-01-15 14:30:00
Size: 524,288 bytes

Directory Structure:
  Offset: 8192
  Chunks: 512
  Chunk Size: 4096 bytes
  First PMGL: 0
  Last PMGL: 15
  Directory pages: 16

Sections:
  Section 0 (Uncompressed):
    Offset: 2048
    Files: 5

  Section 1 (MSCompressed):
    Compression: LZX
    Files: 10

File Statistics:
  Total files: 15
  Regular files: 12
  System files: 3

  Compressed (Sec1): 10 files
  Uncompressed (Sec0): 5 files

Regular Files:
  /index.html
    Size: 15,234 bytes
    Section: 1 (MSCompressed)

  /style.css
    Size: 2,048 bytes
    Section: 1 (MSCompressed)

  /images/logo.png
    Size: 8,192 bytes
    Section: 0 (Uncompressed)

System Files:
  /#SYSTEM
    Size: 512 bytes
    Section: 0 (Uncompressed)
  /#TOPICS
    Size: 1,024 bytes
    Section: 0 (Uncompressed)
  /#URLSTR
    Size: 256 bytes
    Section: 0 (Uncompressed)

Common Errors

Invalid CHM signature: File is not a valid CHM archive
Corrupt directory: CHM directory structure is damaged

chm-create - Create CHM File

Create a new CHM file from HTML and other files.

Syntax

cabriolet chm-create [OPTIONS] OUTPUT FILES...

Parameters

OUTPUT: (required) Path for the new CHM file
FILES…: (required) One or more files to add

Options

--window-bits=SIZE: LZX window size in bits: 15-21 (default: 16)
--verbose, -v: Show creation progress

Returns

Exit code 0 on success
Exit code 1 on error
Exit code 2 if no files specified
Exit code 3 if source files not found
Exit code 4 if permission denied

Description

The chm-create command builds a new CHM archive from HTML and resource files. HTML files are compressed in Section 1 (MSCompressed), while images and other media are stored uncompressed in Section 0.

Examples

Create with default settings

cabriolet chm-create help.chm index.html style.css logo.png

Output

Created help.chm (45,056 bytes, 3 files)

Create with larger LZX window

cabriolet chm-create --window-bits=21 help.chm docs/*.html

Output

Created help.chm (128,512 bytes, 15 files)

Create with verbose output

cabriolet chm-create --verbose --window-bits=18 help.chm index.html style.css

Output

Creating help.chm with window_bits: 18

Adding files:
  index.html -> /index.html (compressed)
    Original: 15,234 bytes
    Section: 1 (MSCompressed)

  style.css -> /style.css (compressed)
    Original: 2,048 bytes
    Section: 1 (MSCompressed)

Writing CHM structure...
  ITSF header: 96 bytes
  Directory chunks: 4,096 bytes
  Section 0 (Uncompressed): 0 bytes
  Section 1 (MSCompressed): 8,192 bytes

Created help.chm
  Total: 2 files
  Compressed size: 12,384 bytes
  Compression ratio: 28.1%

Create from directory

cabriolet chm-create help.chm html/*.html images/*.png

Common Errors

No files specified: Provide at least one file to add
Cannot create output file: Verify write permissions and disk space
Source file not found: Check all file paths are correct
Window bits out of range: Use value between 15 and 21

Global Options

All CHM commands support these global options:

--verbose, -v: Enable verbose output with detailed progress
--help, -h: Display command help
--version: Show Cabriolet version

See link: for complete details.

Exit codes

Code	Meaning
0	Success
1	General error
2	Invalid arguments
3	File not found
4	Permission denied
5	Corrupt archive
6	Unsupported format

Next steps

Review Basic Usage Guide for usage examples
Study Ruby API Reference for Ruby integration
Learn about compression algorithms

CHM Commands Reference

Purpose

References

Concepts

Command Overview

chm-list - List CHM Contents

Syntax

Parameters

Options

Returns

Description

Examples

Common Errors

See Also

chm-extract - Extract CHM Files

Syntax

Parameters

Options

Returns

Description

Examples

Common Errors

See Also

chm-info - Show CHM Information

Syntax

Parameters

Options

Returns

Description

Examples

Common Errors

See Also

chm-create - Create CHM File

Syntax

Parameters

Options

Returns

Description

Examples

Common Errors

See Also

Global Options

Exit codes

Next steps

Bibliography