./Ilia Munaev – Software Engineer

Rebuild. C Standard Library (C language)

Overview

A custom implementation of core C standard library functionality, written from scratch in C.
Serves as the foundational library for all subsequent C-based projects.

Source Code

» GitHub repository

Purpose

  • Reimplement standard C library primitives to understand their exact behavior
  • Build a reliable, reusable base for systems-level development
  • Practice disciplined memory management and low-level API design

Technical Highlights

  • Memory manipulation (memcpy, memmove, calloc, realloc)
  • String handling and parsing utilities
  • Character classification and conversion
  • Numeric conversions (atoi, itoa, base conversion)
  • File-descriptor-based I/O helpers
  • Custom implementations of:
    • printf (formatted output)
    • get_next_line (line-by-line file reading)

Design Notes

  • Matches standard C library semantics, including edge cases
  • Explicit memory ownership and error handling
  • No external dependencies beyond libc
  • Extended with helper utilities reused in larger projects (shell, web server)

Outcome

  • Stable, reusable library used across all C projects
  • Deep familiarity with undefined behavior and memory edge cases
  • Strong foundation for debugging, security research, and low-level development