MagicEcho
Posted: 12 May 2015 10:46
Inspired from Supress % (percent sign) escaping in a CMD file? I build a magicEcho that can echo any content behind it.
So when you write
You get literally as output
Obviously this shouldn't be possible
So here is the code.
I will explain it later (the explanation will be long), but for now you can find out how it works for yourself
PS:
The code would be much easier if unlimited nested blocks where possible,
but they fail with a strange side effect Enabling the internal debug outputs of cmd.exe
So when you write
Code: Select all
%magicEcho% "^!%path%<>" ^%!%<> ^You get literally as output
Output wrote:"^!%path%<>" ^%!%<> ^
Obviously this shouldn't be possible
So here is the code.
I will explain it later (the explanation will be long), but for now you can find out how it works for yourself
Code: Select all
@echo off
call :magicEcho.init
%magicEcho% This is impossible %path% ^& | <> "^& | <>" ^
echo Or not?
exit /b
:magicEcho.init
set "magicEcho=call :gn & REM # #"
exit /b
:magicEcho
setlocal EnableDelayedExpansion
set /a skip=ln-2
setlocal DisableDelayedExpansion
FOR /F "usebackq skip=%skip% delims=" %%L in (`findstr /n "^" "%~f0"`) do (
set "line=%%L"
setlocal EnableDelayedExpansion
set "line=!line:*:=!"
set "line=!line:*echo%% =!"
if defined line echo(!line!
endlocal
exit /b
)
exit /b
:gn
setlocal EnableDelayedExpansion
for %%F in ("%~f0") do set /a size=%%~zF
set "empty=."
for /L %%n in (1 1 13) DO set "empty=!empty:~0,4000!!empty:~0,4000!"
set LF=^
REM ***
set /a blockSizeHalf=4000, blockSize2=blockSizeHalf*2+2
copy "%~f0" "%~f0.tmp" > NUL && (
set /a charCount=0, lo=0, sl=0, preChars=0, lnr=0, cnt=0
for /F "usebackq delims=:" %%O in (`findstr /o "^" "%~f0"`) DO (
set "offset=%%O"
set /a lnr+=1
set /a diff=offset-lo, lo=offset
set /a charCount+=diff
if !diff! GEQ 12 (
set "output=%%#:#=!sl!,!preChars!%%"
set "s=!output!#"
set "len=0"
for %%P in (16 8 4 2 1) do (
if "!s:~%%P,1!" NEQ "" (
set /a "len+=%%P"
set "s=!s:~%%P!"
)
)
set /a fill=charCount-len-1
for /F %%L in ("!fill!") DO set "output=!output!!empty:~0,%%L!!LF!"
set /a cnt+=1
set "line!cnt!=!output!"
set /a charCount=0, sl=lnr, preChars=offset
)
)
(
(
for /L %%n in (1 1 !cnt!) DO (
<nul set /p ".=!line%%n!"
)
(echo()
echo :"
echo (
echo setlocal EnableDelayedExpansion
echo FOR /F "tokens=1,2 delims=," %%%%A in ("^!offset^!"^) DO set /a line=%%%%A,label=%%%%B
echo copy "%~f0.tmp" "%~f0" > NUL
echo set /a size=%size%
echo set L=^^
(echo()
(echo()
echo for /L %%%%n in (1 1 13^) DO set "L=^!L:~0,%blockSizeHalf%^!^!L:~0,%blockSizeHalf%^!"
echo set /a remainSize=label-11, blocks=remainSize/%blockSize2%, remainSize=remainSize-%blockSize2%*blocks-2
echo if ^^!remainSize^^! LSS 2 set /a remainSize+=%blockSize2%, blocks-=1
echo FOR /F %%%%R in ("^!remainSize^!"^) DO set "lastBlock=^!L:~-%%%%R^!)"
echo (
echo (echo :#^)
echo (echo (%%%%#%%%%^)
echo FOR /L %%%%n in (1 1 ^^!blocks^^!^) DO (echo(^^!L^^!^)
echo (echo(^^!lastBlock^^!^)
echo echo(
echo ^) ^> "%~f0"
echo set ^^^^^"#=endlocal ^^^^^& (copy "%~f0.tmp" "%~f0" ^^^^^&^^^^^& del "%~f0.tmp"^^^^^) ^^^^^> nul ^^^^^& set "ln=^!line^!" ^^^^^& call :magicEcho"
echo goto :#
echo ^)
) > "%~f0"
endlocal
set "#=<nul set offset=# & goto :":"
exit /b
)
)
echo FAIL
exit /b
PS:
The code would be much easier if unlimited nested blocks where possible,
but they fail with a strange side effect Enabling the internal debug outputs of cmd.exe
