magic.cpp File Reference

Implementation of the Magic class and supporting utilities. More...

#include <cmath>
#include <array>
#include <utility>
#include "magic.hpp"
#include <magic.h>

Include dependency graph for magic.cpp:

Classes
class	Recognition::Magic::MagicPrivate
	PIMPL implementation class for Magic. More...
struct	Recognition::Magic::MagicPrivate::FlagsConverter
	Converter between C++ flag types and libmagic flag values. More...
struct	Recognition::Magic::MagicPrivate::LibmagicPairConverter
	Extracts values from libmagic constant pairs. More...

Namespaces
namespace	Recognition
	Root namespace for the libmagicxx library.
namespace	Recognition::Detail
	Internal namespace for libmagic C library integration.

Functions
std::string	Recognition::ToString (const Magic::FileTypeEntryT &file_type_entry, const std::string &type_separator=" -> ")
	Convert a file type entry to a string.
std::string	Recognition::ToString (const Magic::FileTypeMapT &file_type_map, const std::string &type_separator=" -> ", const std::string &file_separator="\n")
	Convert a file type map to a string.
std::string	Recognition::ToString (const Magic::ExpectedFileTypeT &expected_file_type)
	Convert an expected file type result to a string.
std::string	Recognition::ToString (const Magic::ExpectedFileTypeEntryT &expected_file_type_entry, const std::string &type_separator=" -> ")
	Convert an expected file type entry to a string.
std::string	Recognition::ToString (const Magic::ExpectedFileTypeMapT &expected_file_type_map, const std::string &type_separator=" -> ", const std::string &file_separator="\n")
	Convert an expected file type map to a string.
std::string	Recognition::ToString (Magic::Flags flag)
	Convert a Magic flag to its string name.
std::string	Recognition::ToString (const Magic::FlagsContainerT &flags, const std::string &separator=", ")
	Convert a container of flags to a string.
std::string	Recognition::ToString (Magic::Parameters parameter)
	Convert a Magic parameter to its string name.
std::string	Recognition::ToString (const Magic::ParameterValueT &parameter_value, const std::string &value_separator=": ")
	Convert a parameter-value pair to a string.
std::string	Recognition::ToString (const Magic::ParameterValueMapT &parameters, const std::string &value_separator=": ", const std::string &parameter_separator=", ")
	Convert a parameter-value map to a string.

Detailed Description

Implementation of the Magic class and supporting utilities.

This file contains the complete implementation of the libmagicxx library, including:

• Magic::MagicPrivate (PIMPL implementation class)
• Magic class public method implementations
• ToString() free function overloads for string conversion

Architecture

The implementation uses the PIMPL (Pointer to IMPLementation) idiom to:

• Hide implementation details from the public header
• Minimize compilation dependencies (libmagic headers are internal)
• Enable ABI stability across library versions

libmagic Integration

The underlying libmagic C library is wrapped in the Detail namespace to isolate its symbols. All libmagic calls go through MagicPrivate, which:

• Manages the magic cookie (libmagic handle) via RAII
• Converts between C++23 types and C types
• Translates libmagic error codes to exceptions or std::expected

Key Components

Component	Purpose
Detail::magic_*	Wrapped libmagic C functions
MagicPrivate	PIMPL class holding cookie and state
MagicPrivate::FlagsConverter	Converts between flag representations
MagicPrivate::LibmagicPairConverter	Extracts values from flag/param pairs
MagicPrivate::ThrowExceptionOnFailure	Error handling template
ToString() overloads	String conversion utilities

Lifecycle Implementation

The three-state lifecycle (Closed -> Opened -> Valid) is tracked by:

• m_cookie: nullptr means Closed, non-null means Opened
• m_is_database_loaded: true only after successful LoadDatabaseFile()
• IsValid() = IsOpen() && IsDatabaseLoaded()

See also

magic.hpp for the public API documentation

Magic class documentation for lifecycle state diagram

Author

Oğuz Toraman

Copyright

Copyright (c) 2022-2026 Oğuz Toraman. LGPL-3.0-only.