kell

This is a POSIX shell written in Haskell.

Try it out

Just type

cabal build
cabal test    # optional to run tests
cabal install
kell

Features

The following features are implemented

• Line based Interpreter
  • parses a line and if it the parser fails with unexpected end of input tries to fetch an additional one
  • distinguish interactive mode (prompt and no exit on a large class of errors)
• Word expansions:
  • Parameter expansion
  • Command substition
  • Arithmetic expansion
• Variable assignments
• Input/Output redirections
• Execution of simple commands
• And-Or lists
• Asynchronous command execution (very basic only)
• Control structures:
  • If conditionals
  • While loops
• Some unit testing testing standard out and exit status of scripts against the shell in CI of Github

Not implemented, but soon to be:

• Tilde expansions
• More correct error handling
• Signal traps
• Built-in utilities
• Pattern matching
• Here-Documents
• Use a different string format like Bytestring or Text, that is not lazy and thus slow
• Source documentation with haddock

Other

The shell can be crosscompiled to target the Sortix operating system with this ghc-toolchain.

Please note, that you will need statically linked versions of gmp and iconv on your host-system for this to work.