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      ECHO text^   next line is joined (line continuation)

SH MODE
    Any line whose first token contains a lowercase letter is a SH line. SH
    sections are executed by BATsh::SH, which implements:

      VAR=value, export VAR=value, unset VAR
      echo, printf
      if/then/elif/else/fi
      for VAR in list; do ... done
      while condition; do ... done
      until condition; do ... done
      case $var in pat1|pat2) ... ;; *) ... ;; esac
        (case: |-patterns, * ? [abc] [a-z] [!abc] globs, quoted/literal
         patterns, and the bash ;& / ;;& fall-through terminators)
      trap 'cmd' SIG... / trap - SIG / trap '' SIG / trap [-p]
        (EXIT pseudo-signal plus a pure-Perl %SIG bridge for real signals)
      test / [ ... ]  (file, string, and integer comparisons)
      cd, pwd, exit, true, false, :, read, shift [N], local VAR=value
      $(( arithmetic )) -- +, -, *, /, %, and $1..$9 inside
      $( command ) and `command`  (command substitution, nested)
      cmd1 | cmd2 [| cmd3 ...]  (pipeline via temporary file)
      cmd1 && cmd2, cmd1 || cmd2, cmd1 ; cmd2  (compound commands)
      > >> < 2> 2>> 2>&1 1>&2  (I/O redirection)
      cmd << DELIM ... DELIM    (here-document; <<-DELIM, <<'DELIM' too)
      cmd &                     (background execution; external commands)
      name() { ... }, function name { ... }  (function definitions)
      $VAR, ${VAR}, $1..$9, $@, $*, $#, $?, $$, $0, $!
      ${VAR:-default}, ${VAR:=default}, ${VAR:+alt}
      ${VAR%pat}, ${VAR%%pat}   -- shortest/longest suffix removal
      ${VAR#pat}, ${VAR##pat}   -- shortest/longest prefix removal
      ${VAR/pat/rep}, ${VAR//pat/rep}  -- first/all substitution
      ${VAR^^}, ${VAR^}, ${VAR,,}, ${VAR,}  -- case conversion
      ${VAR:N:L}, ${VAR:N}  -- substring
      ${#VAR}  -- string length
      arr=(a b c), arr+=(d e), arr[i]=v  -- indexed arrays
      declare -a arr, declare -A map, typeset ...  -- array declaration
      map=([k]=v ...), map[k]=v  -- associative arrays
      ${arr[i]}, ${map[key]}, $arr (== ${arr[0]})  -- element access
      ${arr[@]}, ${arr[*]}, ${#arr[@]}, ${#arr[i]}, ${!arr[@]}
      unset arr, unset arr[i]
      source / . file

INSTALLATION
    To install from CPAN:

        cpan BATsh

    To install from a distribution tarball:

        perl Makefile.PL
        make
        make test
        make install

    No non-core dependencies are required.

REQUIREMENTS
    Perl 5.005_03 or later. Core modules only. No external shell required.

BUGS AND LIMITATIONS
    Commands that are not built in -- "FINDSTR", "SORT", "MORE", "CHOICE",
    "TIMEOUT", "XCOPY", "ROBOCOPY" and the like in CMD mode, and any
    non-builtin program in SH mode -- are NOT reimplemented in Perl. They
    are invoked as external programs (via Perl's "system"), so they work
    only where the host operating system provides the corresponding
    executable (e.g. FINDSTR.EXE on Windows). Only the built-in command set
    is guaranteed to run identically on every platform.

    The built-in CMD interpreter does not implement:

    Variable substring "%VAR:~n,m%" / "%VAR:~n%" / "%VAR:~-n%" and
    substitution "%VAR:str1=str2%" / "%VAR:*str1=str2%" are supported as of
    version 0.05. Dynamic pseudo-variables "%DATE%" (YYYY-MM-DD), "%TIME%"
    (HH:MM:SS.cc), "%CD%", "%RANDOM%" (0-32767), "%ERRORLEVEL%", and
    "%CMDCMDLINE%" are also supported as of version 0.05.

    *   "FOR /F" with "usebackq" backtick-quoted commands on Windows (the
        "cmd /c" subprocess path is untested on Windows).

    The built-in SH interpreter does not support:

    *   Filename (pathname) globbing such as "echo *.txt" or "for f in
        *.pl". The "*", "?" and "[abc]" metacharacters are honoured in
        "case" patterns and in "${VAR%pat}" / "${VAR#pat}" expansion only,
        not for expanding filenames on the command line.

    *   Tilde expansion "~/path" and "~user" (only "cd" with no argument
        uses "$HOME").

    *   Brace expansion "{a,b}" and "{1..5}".

    *   Here-strings ("<<< word") and process substitution ("<(cmd)",
        ">(cmd)").

    *   The shell options "set -e", "set -u", "set -x", and the builtins
        "getopts", "select", "alias", "eval" and "exec".

    Common to both modes: a parenthesised group "( ... )" does not run in a
    separate sub-shell; it shares the one variable store, so there is no
    variable-scope isolation.

    Here-documents ("<<", "<<-", "<<'DELIM'") ARE supported on STDIN, with
    these limitations:

    *   Recognised only in SH mode; "<<" has no meaning in CMD mode.

    *   One here-document per command line only (no "cmd <<A <<B").

    *   Here-strings ("<<< word") are not supported.

    *   Combining a here-document with a pipeline or compound operator on
        the same line is best-effort only; use a separate command.

    *   The closing delimiter must be on a line by itself and match
        exactly (after tab stripping for "<<-").

    Background execution (a trailing "&") IS supported in SH mode, with
    these limitations:

    *   Applies to external commands only. A trailing "&" on a built-in, a