NAME
    BATsh - Bilingual Shell: cmd.exe and bash in one script (self-contained)

VERSION
    Version 0.01

SYNOPSIS
      use BATsh;

      BATsh->run('myscript.batsh');
      BATsh->run_string('echo hello from sh');
      BATsh->repl();

DESCRIPTION
    BATsh is a self-contained bilingual shell interpreter written in pure
    Perl. It implements both the cmd.exe command set and the sh/bash command
    set entirely in Perl -- no external cmd.exe, bash, or sh is required.

    Scripts are divided into CMD sections (uppercase first token) and SH
    sections (lowercase first token). Both sections share a common variable
    store via BATsh::Env, so variables set in a CMD section are immediately
    visible in the next SH section and vice versa.

CMD MODE
    Any line whose first token is all uppercase (A-Z, 0-9, path chars) is a
    CMD line. CMD sections are executed by BATsh::CMD, which implements:

      ECHO, @ECHO OFF/ON
      SET VAR=value, SET /A expr
      IF "A"=="B" ... ELSE ..., IF EXIST, IF DEFINED, IF ERRORLEVEL
      FOR %%V IN (list) DO ..., FOR /L %%V IN (s,step,e) DO ...
      GOTO :label, :label
      CALL :label [args], CALL file.batsh
      SETLOCAL, ENDLOCAL
      CD, DIR, COPY, DEL, MOVE, MKDIR, RMDIR, REN, TYPE
      PAUSE, EXIT, CLS, TITLE, VER, PUSHD, POPD

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 pattern) ... ;; esac
      test / [ ... ]  (file tests, string, integer comparisons)
      cd, pwd, exit, true, false, :, read, shift
      $(( arithmetic )), $( command substitution )
      ${VAR}, ${VAR:-default}, ${VAR:=default}
      source / . file

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

BUGS AND LIMITATIONS
    The built-in CMD interpreter does not support all cmd.exe extensions
    (e.g. FOR /F with complex token options, delayed expansion with !VAR!).

    The built-in SH interpreter does not support pipelines (|), redirection
    (> >> <), background execution (&), or here-documents (<<).

    Section boundary detection is token-based (uppercase vs. lowercase first
    token). Mixed-case first tokens are treated as SH.

    Please report bugs via the issue tracker:
    <https://github.com/ina-cpan/BATsh/issues>

SEE ALSO
    BATsh::CMD, BATsh::SH, BATsh::Env

AUTHOR
    INABA Hitoshi <ina@cpan.org>

LICENSE
    This software is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.