README.md

Possible project proposal?

• https://github.com/charmoniumQ/merkle-tree-file-system

How the UNIX Shell works (Sam)

• fork() and execve() syscalls
• /usr/bin/[ is just a symlink to /usr/bin/test
  • /usr/bin/[, 1, =, 2, ] returns 1
  • /usr/bin/[, 1, =, 1, ] returns 0

$ echo -e '#!/usr/bin/env python\nimport sys; print(sys.argv)' > script.py
$ chmod +x script.py
$ a='1 2 3'
$ ./script.py $a
["./script.py", "1", "2", "3"]
$ ./script.py $a
["./script.py", "1 2 3"]

• Bash re-reads the script as it is executing!
• Unix Haters Handbook page 147
• Examples: https://samgrayson.me/2021-01-01-shell/

Fish shell (Russel)

• https://fishshell.com/
• Good defaults
• Tab-completes options from man-page
• Fish automatically searches for previous commands
• Zsh shell can try to have the same features, not as good.
  • https://github.com/marlonrichert/zsh-autocomplete
  • https://github.com/zsh-users/zsh-syntax-highlighting
  • Not default! Zsh users have to configure!

Oil shell (Evan)

• https://www.oilshell.org/
• Better for-loop syntax
• Better variable syntax

Ammonite shell (Sam)

• Slides: https://docs.google.com/presentation/d/11vZzXCfAA0aOFAuHA0nAvAzALGFGCH-dqHxx6XMgbk8
• Shell underlies important applications/orchestration but has low guarantees! (no typesafety)
• But at least it's concise? Safer alternatives are very verbose (Python, Java, Scala)
• Develop a Scala library to make it less verbose (still using Scala REPL)
• Develop a Scala REPL suitable for system shell.
  • No more than twice as verbose as Bash.