firmware-base/docs-c/core/StringUtils.md

title	description	keywords
StringUtils - String Manipulation Utilities	A utility class for string manipulation and type conversion for ESP-32 applications	ESP-32, C++17, string utilities, type conversion, industrial application, Modbus

StringUtils

Path: src/modbus/StringUtils.h

Revision History: Initial documentation

StringUtils provides a set of utility functions for string manipulation and type conversion in an industrial ESP-32 application. It enables parsing and converting string values to native C types, which is particularly useful for configuration and communication scenarios in Modbus applications.

REQUIREMENTS

No specific hardware pins are required as this is a software utility helper.

PROVIDES

• E_VALUE_TYPE enumeration for representing different value types
• Template function convertTo<T> for converting strings to various native types
• Type detection functions (isInteger, isFloat, detectType)
• Hex data printing utility

FEATURES

• Specialized template implementations for converting strings to:
  • Integer types (int, short, long int)
  • Floating-point (float)
  • Boolean values (bool)
• Type detection to determine if a string represents a valid integer or floating-point value
• Platform-specific adaptations for string tokenization across different compilers
• Hex data visualization for debugging

DEPENDENCIES

• ./xtypes.h
• Standard C libraries: <stdio.h>, <string.h>, <ctype.h>, <stdlib.h>

graph TD
    StringUtils --> xtypes
    StringUtils --> "Standard C Libraries"

BEHAVIOUR

The StringUtils component follows a simple conversion and detection workflow:

graph LR
    Input[Input String] --> Detect[Detect Type]
    Detect --> |Integer| ConvertInt[Convert to Integer]
    Detect --> |Float| ConvertFloat[Convert to Float]
    Detect --> |Boolean| ConvertBool[Convert to Boolean]
    Detect --> |Text| HandleText[Handle as String]
    ConvertInt --> Result[Native Type Result]
    ConvertFloat --> Result
    ConvertBool --> Result
    HandleText --> Result

TODOS

PERFORMANCE

• Consider using strtol, strtof, etc. for all conversions to provide better error handling
• Optimize the string scanning operations for large strings
• Add string length validation to avoid buffer overruns

SECURITY

• Add input validation to prevent exploitation through malformed strings
• Consider adding bounds checking for numeric conversions
• Implement sanitization for strings that will be used in sensitive contexts

COMPLIANCE

• Ensure compatibility with C17 standard
• Verify that all functions work correctly in the target ESP-32 environment
• Audit for potential compliance issues with industrial standards

RECOMMENDATIONS

• Extend type support to include additional numeric types as needed
• Add more robust error handling for conversion failures
• Consider adding string formatting utilities for consistent output generation
• For improved performance, use static or cached conversions for frequently used values