BATsh
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echo out > /tmp/out.txt
BATSH
# Perl 5.005_03 and later; pure-Perl, no external shell required.
DESCRIPTION
Executive Summary
BATsh is a self-contained bilingual shell interpreter written in pure
Perl. It runs cmd.exe batch syntax and bash/sh syntax in the same script
file, switching automatically between CMD mode and SH mode on a
line-by-line basis. No external cmd.exe, bash, or sh is required --
everything runs inside Perl.
Mixed-Mode Sample
The following script demonstrates cmd.exe and bash sections coexisting
and sharing variables through the common BATsh::Env variable store.
:: -- CMD section: sets a variable and calls a SH function via bridge --
@ECHO OFF
SET LANG=BATsh
SET COUNT=3
# -- SH section: reads CMD variables, uses functions and pipeline --
greet() {
echo "Hello from $1 (bash/sh mode)"
}
greet $LANG
for i in 1 2 3; do echo " item $i of $COUNT"; done
result=$(echo "$LANG" | perl -e 'while(<STDIN>){chomp;print uc}')
echo "Uppercase: $result"
echo "log line" >> /tmp/batsh_demo.txt
:: -- CMD section again: reads variable set by SH side --
ECHO Back in CMD mode
ECHO Uppercase result: %result%
BATsh features (both modes): pipelines (|), I/O redirection (> >> <
2>&1), variable expansion (${var%pat} ${var^^} ${#var}), functions,
shift, local.
FULL 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 (arithmetic)
SET /P VAR=Prompt (interactive prompt input from STDIN)
IF "A"=="B" ... ELSE ..., IF /I (case-insensitive), IF NOT
IF EXIST "path with spaces", IF DEFINED var, IF ERRORLEVEL n
FOR %%V IN (list) DO ..., FOR /L %%V IN (s,step,e) DO ...
FOR /F "tokens= delims= skip= eol= usebackq" %%V IN (src) DO ...
GOTO :label, :label, GOTO :EOF
CALL :label [args], CALL file.batsh
SHIFT, SHIFT /N
SETLOCAL [ENABLEDELAYEDEXPANSION|DISABLEDELAYEDEXPANSION], ENDLOCAL
CD, DIR, COPY, DEL, MOVE, MKDIR, RMDIR, REN, TYPE
PAUSE, EXIT [/B] [code], CLS, TITLE, VER, PUSHD, POPD
cmd1 | cmd2 (pipeline via temporary file)
&, &&, || (sequential, conditional-and, conditional-or)
Variable Expansion
"%VAR%" references are expanded before each line is dispatched. Variable
names are case-insensitive ("SET foo=x" is visible as "%FOO%").
Inside parenthesised IF and FOR blocks, "%VAR%" is expanded at parse
time (before any commands in the block run), matching cmd.exe behaviour.
To see a value updated inside a block, use delayed expansion:
SETLOCAL ENABLEDELAYEDEXPANSION
SET X=old
IF 1==1 (
SET X=new
ECHO !X! &:: prints "new" (delayed)
ECHO %X% &:: prints "old" (parse-time)
)
ENDLOCAL
Batch Parameters
%0 is the script path (absolute); %1..%9 are positional arguments; "%*"
is all arguments joined by space. "SHIFT" / "SHIFT /N" shifts the
positional parameters. "CALL :label" saves and restores caller's
arguments.
Batch-parameter tilde modifiers expand %0..%9 components:
%~0 dequote (strip surrounding "...")
%~f1 full absolute path of %1
%~d1 drive letter only (e.g. C:)
%~p1 directory path only (with trailing /)
%~n1 filename without extension
%~x1 extension only (e.g. .bat)
%~dp0 drive + directory (most common usage)
%~nx1 filename + extension
Redirection and Compound Commands
ECHO text > file stdout overwrite
ECHO text >> file stdout append
prog 2> err.txt stderr redirect
& cmd sequential execution
cmd1 && cmd2 run cmd2 only if cmd1 succeeded (ERRORLEVEL 0)
cmd1 || cmd2 run cmd2 only if cmd1 failed (ERRORLEVEL != 0)
The "^" character escapes the next character:
ECHO a^&b prints a&b (& not treated as compound separator)
ECHO a^^b prints a^b
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:
( run in 0.572 second using v1.01-cache-2.11-cpan-98e64b0badf )