Writing a Unix Shell – Part II
If you want to learn more about writing a shell from an undergraduate coursework perspective (and far closer to how bash does things), this is a chapter entirely on writing your own shell: https://www.cs.purdue.edu/homes/grr/SystemsProgrammingBook/B...That PDF covers the basics of making your own shell (i.e. splitting input into tokens aka using a lexer, parsing the resulting tokens aka using yacc [a token parser], I/O redirection, piping, executing commands, wildcarding, interrupts, environmental variables, history, subshell, revising what you've typed without having to retype it, etc.).Every undergraduate CS major at Purdue University is required to do the infamous shell lab (essentially, recreate csh). This project really taught me how shells work. Before doing this project, I could do the minimum in shells, but now I'm fairly competent at it.