Explore the world of syscalls in this RustConf 2019 talk by Gargi Sharma. Dive into the interface between operating systems and user programs, learning how syscalls work and their importance even in simple Rust programs. Discover the power of strace for debugging, performance analysis, and examining program internals. Follow along as Sharma demonstrates how to write a custom syscall tracer in Rust, covering topics such as systems programming languages, functional programming, and the intricacies of reading from files. Gain insights into key concepts like MCtrace, STrace, PTrace, and parent namespaces, while exploring system codes and sys values. Conclude with a practical demo and comprehensive understanding of syscalls in the Rust ecosystem.