bash-to-ayrton.md

• posix WONTDO

• simple commands DONE

• pipelines ( a | b ) DONE

  • |&
  • exit status:
    • last command CHECK
    • pipefail -> last, right-most non-zero
    • PIPESTATUS
    • ! bool CHECK
  • time -> sys + user times
    • implement as time() function?
  • lastpipe can't be implemented WONTDO

• lists:

  • ;, WONTDO
  • &, _bg=True DONE
    • return status is 0
  • &&, and DONE
  • || or DONE

• Compound commands

  • (list) subshell MAYBE

    • could be implemented with with

  • {} (block) DONE

  • (()) arithmetic expression CHECK

  • [[]] conditional expression w/o word split or path exp. WONTDO

  • ==, != right op as pattern, see patter matching CHECK

  • =~ re DONE

  • () (precedence) DONE

  • ! DONE

  • && DONE

  • || DONE

  • for DONE

  • for (( e1; e2; e3 )) do... WONTDO

  • select MAYBE

  • case WONTDO

    • use if + elif

  • if DONE

  • while DONE

  • until WONTDO

• coproc MAYBE

• function definitions DONE

• quoting DONE

  • python flavor

• parameters

  • variables DONE

  • no value -> null WONTDO

  • tilde, parameter, variable expansion use expansions MANUAL

  • quote removal WONTDO

  • integer attribute int DONE

  • "$@" DONE

  • nameref globals() or locals() ` DONE

  • positional args + function params DONE

  • special

    • •                                               `args[1:]` or `for arg in args`
                                                                            DONE
        

    • @ args DONE

    • len(args) DONE

    • ? command.exit_status DONE

    • •                                                                     WONTDO
        

    • $ os.getpid() DONE
    • ! CHECK
    • 0 CHECK
    • _ WONTDO

  • shell variables

    • IFS

  • arrays list, dict DONE

    • NOTE: python lists can't be sparse, use a dict
    • declare -a list DONE
    • declare -A dict DONE
    • assign DONE
      • python flavor
    • ${name[subscript]} name[subscript] DONE
      • "${name[*]}" IFS[0].join(name) DONE
      • "${name[@]}" name DONE
    • expansion in word string formatting + `name[0] DONE
    • ${#name[subscript]} len(name[subscript]) DONE
    • ${#name[@]} len(name) DONE
    • ${name[-x]} name[-x] DONE
    • ${name} name[0] DONE
    • create array on assign to subscript WONTDO
    • ${!name[@]} range(len(name)), name.keys() DONE
    • unset name[@] del name DONE
    • pathname expansion use path expansion manually CHECK
    • read -a

• expansion (in that order)

  • brace

    • explodes words
    • pre{c,s,v}pos -> [ precpos, prespos, prevpos ] CHECK
    • nested CHECK
    • {x..y[..incr]}

      • digits

      • chars

      • y inclusive

      • auto -1 if x>y

      • non-correct are left untouched

      • ${ is not brace expansion, inhibit

      • remove braces

      • mkdir /usr/local/src/bash/{old,new,dist,bugs}

      • chown root /usr/{ucb/{ex,edit},lib/{ex?.?*,how_ex}}

    • 0 prefix "%0...d" CHECK

  • tilde

    • tilde prefix
      • login name
      • not login or expansion fails -> untouched
    • null string -> $HOME
      • HOME unset -> home dir (as per /et/passwd?)
    • ~[N]+
    • ~[N]-
    • ~N
    • automatic expansion on assignment

  • parameter/variable

    • explodes words if "$@" or "${name[@]}"
    • $/${} use f-strings DONE
    • ${parameter} %(parameter)s DONE
    • ${!parameter} globals()[parameter], locals()[parameters] DONE
      • tilde, parameter, command, arithmetic CHECK
      • nameref %(nameref) DONE
    • word
      • tilde, parametr, command, arithmetic
    • ${parameter:-word}
    • ${parameter:=word}
    • ${parameter:?word}
    • ${parameter:+word}
    • ${parameter:offset} parameter[offset:] DONE
    • ${parameter:offset:length} parameter[offset:offset+length] DONE
      • python offers more consistency and flexiblility parameter[start:end], parameter[:end]
      • arrays DONE
      • undefined on dicts exception CHECK
    • ${!prefix*} MAYBE
    • ${!name[@]} name.keys() DONE
    • ${#parameter} len(name) DONE
      • even for array lengths
    • ${parameter#word} TODO
      • word is filename expanded
      • doable with str methods
    • ${parameter%word} TODO
      • word is filename expanded
      • doable with str methods
    • ${parameter/pattern/string} parameter.replace(), re.replace DONE
      • pattern is file-expanded
      • / count in replace() DONE

      • re.replace(), ^ DONE

      • % re.replace(), $ DONE
      • // repalce with '' DONE
      • nocasematch re.replace() DONE
      • @ args, but not on functions DONE
      • apply on all elements in an array
    • ${parameter^pattern}
      • pattern is file-expanded
    • ${parameter@operator} WONTDO
      • Q
      • E
      • P
      • A
      • a

  • Command substitution

  • command substitution (LtR)

  • arithmetic

  • word splitting

    • explodes words

  • pathname

    • explodes words

  • process (in any of tilde, parameter, arithmetic, command)

  • quote removal WONTDO

  • += +=, .append() DONE

  • alias define function WONTDO

  • declare WONTDO

  • export CHECK

  • local local DONE

  • global global DONE

  • read

    • read -a

  • readonly WONTDO

  • typeset WONTDO

  • unset del DONE