A simple shell written in C for MIT's xv6 operating system All of the rest is runtime environment (xv6 OS), the shell implementation is in user/nsh.c
xv6 is a re-implementation of Dennis Ritchie's and Ken Thompson's Unix Version 6 (v6). xv6 loosely follows the structure and style of v6, but is implemented for a modern RISC-V multiprocessor using ANSI C.
ACKNOWLEDGMENTS
xv6 is inspired by John Lions's Commentary on UNIX 6th Edition (Peer to Peer Communications; ISBN: 1-57398-013-7; 1st edition (June 14, 2000)). See also https://pdos.csail.mit.edu/6.1810/, which provides pointers to on-line resources for v6.
The code in the files that constitute xv6 is Copyright 2006-2022 Frans Kaashoek, Robert Morris, and Russ Cox.
ERROR REPORTS
Please send errors and suggestions to Frans Kaashoek and Robert Morris (kaashoek,rtm@mit.edu). The main purpose of xv6 is as a teaching operating system for MIT's 6.1810, so we are more interested in simplifications and clarifications than new features.
BUILDING AND RUNNING XV6
You will need a RISC-V "newlib" tool chain from https://github.com/riscv/riscv-gnu-toolchain, and qemu compiled for riscv64-softmmu. Once they are installed, and in your shell search path, you can run "make qemu".