11 parts · 11 chapters
C and Systems Programming
The language underneath Node, Python, Postgres, Redis and Linux. Learning C means learning what your runtime does for you: memory you must free, syscalls you must check, and bugs no exception will catch. Measured on an Apple M3 Pro: a one-byte write() syscall costs 512 ns, while buffered fputc costs 18 ns.
Eleven parts: C from zero; pointers and memory; the toolchain (compiler, linker, loader, ELF and Mach-O); system calls; files and descriptors; processes and signals; sockets; threads; memory allocators (malloc at 23 ns versus a bump allocator at 5.4 ns, measured); undefined behaviour and sanitisers; and a capstone that builds a shell, an allocator and an HTTP server.
languageTypes, pointers, arrays, structs and manual memory.
toolchainPreprocess, compile, assemble, link, load.
kernel interfaceSyscalls, descriptors, processes, signals.
networkSockets from socket() to an event loop with poll.
concurrencypthreads, mutexes, condition variables, atomics.
safetyUndefined behaviour, sanitisers, fuzzing.
00
C from Zero
A first program
1 ch · ~8 min01Pointers and Memory
Addresses, ownership, lifetimes
1 ch · ~8 min02The Toolchain: Compiler, Linker, Loader, ELF and Mach-O
Every stage, inspected
1 ch · ~8 min03System Calls
Crossing into the kernel
1 ch · ~8 min04Files and Descriptors
Reading, writing, durability
1 ch · ~8 min05Processes and Signals
fork, exec, wait
1 ch · ~8 min06Sockets
From socket() to an event loop
1 ch · ~8 min07Threads
A bounded queue with pthreads
1 ch · ~8 min08Memory Allocators
From brk to arenas
1 ch · ~8 min09Undefined Behaviour and Sanitisers
Silent bugs, loud tools
1 ch · ~8 min10Capstone: A Shell, an Allocator, an HTTP Server
Three programs, one standard
1 ch · ~8 minBuilt on Computers and OSUses How Computers Work for memory and CPUs and Operating Systems for processes and virtual memory; Kernel Internals continues below this course.