C Standard Library

• https://en.wikipedia.org/wiki/C_standard_library

• https://en.cppreference.com/w/c/header

• Represents a standardised series of functions that must exist on an operating system

• These functions exist to perform most common operations including:

  • Memory management (stdlib.h)
  • File operations (stdio.h)
  • Signal handling
  • Mathematics
  • String handling (string.h)

• The Standard C Library is written to perform the necessary System Calls to achieve these functions, without the calling Binary needing to know the relevant syscalls

• The most common examples on Linux are glibc and musl

• Programs that run before (or below) the kernel (such as a Bootloader) cannot be compiled against a libc and need to have their own ability to perform these functions