Eu escrevi um conjunto de scripts em lote para isso. addpath.bat adiciona elementos ao caminho, rmpath.bat remove elementos do caminho e lpath.bat apenas lista o caminho. Mas então eu precisava de alguns scripts de suporte, então também há chkpath.bat.
Acabou não sendo trivial e exigiu tr.exe e cat.exe, alguns utilitários no estilo unix. O motivo não é trivial: não há backticks no cmd.exe (embora você possa usar loops para isso) e nomes curtos versus nomes longos.
addpath.bat:
@echo off
setlocal
set cwd=%~dps0
goto testit
:loopy
call %cwd%chkpath "%~1"
if %errorlevel%==2 (
set path=%path%;%~1
)
shift
:testit
if not _%1==_ goto loopy
call %cwd%lpath.bat
endlocal & set path=%path%
ChkPath.bat:
@echo off
goto START
-------------------------------------------------------
chkpath.bat
checks path for existence of the given segment.
Returns 1 if present, 2 if not present, 0 if not checked.
The matching and checking complicated by case sensitivity and "short pathnames".
created sometime in 2003 and lovingly maintained since then.
-------------------------------------------------------
:START
setlocal enabledelayedExpansion
set rc=0
set cwd=%~dps0
set curdrive=%~d0
set tr=%curdrive%\bin\tr.exe
set regexe=%windir%\system32\reg.exe
if _%1==_ goto Usage
@REM convert arg 1 to a fully-qualified, short path name,
@REM and then convert to uppercase.
set toupper=%~fs1
call :ToUpper
set tocheck=%toupper%
if not _%TEMP%==_ goto GotTemp
call :gettemp
:GotTemp
set d=%DATE:~4%
set stamp=%d:~6%%d:~3,2%%d:~0,2%%TIME::=%
set d=
set tempfile1=%TEMP%\chkpath1-%stamp%.tmp
echo %path% | %tr% ; \n > %tempfile1%
@REM check each element in the path for the match:
for /f "delims=^" %%I in (%tempfile1%) do (
if !rc!==0 (
call :CheckElt "%%I"
)
)
if %rc%==0 set rc=2
goto END
--------------------------------------------
* checkelt
*
* check one element in the path to see if it is the same
* as the TOCHECK string. The element is first canonicalized.
*
:CheckElt
@REM remove surrounding quotes
set ERF=%1
if [x%ERF%]==[x] goto CheckEltDone
@REM convert to fully-qualified, short paths, uppercase
set TOUPPER=%~fs1%
call :ToUpper
if _%TOCHECK% == _%TOUPPER% set rc=1
:CheckEltDone
goto:EOF
--------------------------------------------
--------------------------------------------
* backtick
*
* invoke a command and return the result as a string.
* This is like backtick in csh or bash.
* To call, set variable BACKTICK to the command to be run.
* The result will be stored in the env variable of the same name.
*
:backtick
FOR /F "usebackq delims=" %%i IN (`%backtick%`) DO (
SET backtick=%%i
)
goto backtick_done
:backtick_none
SET backtick=nothing to exec
:backtick_done
goto:EOF
--------------------------------------------
--------------------------------------------
* gettemp
*
* get the temporary directory, as stored in the registry.
* Relies on backtick.
*
* The result set TEMP.
*
:gettemp
set regkey=HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
set regvalname=Local AppData
set backtick=%regexe% query "%regkey%" /v "%regvalname%"
call :backtick
for /f "tokens=4" %%a in ("%backtick%") do (
set temp=%%a
)
goto:EOF
--------------------------------------------
--------------------------------------------
* ToUpper
*
* Convert a string to all uppercase.
* To call, set variable TOUPPER to the thing to be converted.
* The result will be stored in the env variable of the same name.
*
:ToUpper
FOR /F "usebackq delims=" %%I IN (`echo %toupper% ^| %tr% a-z A-Z`) DO (
SET toupper=%%I
)
goto:EOF
--------------------------------------------
--------------------------------------------
:CleanUp
if _%tempfile1%==_ goto CleanUpDone
if exist %tempfile1% del %tempfile1%
:CleanUpDone
goto:EOF
--------------------------------------------
--------------------------------------------
:Usage
echo.
echo Usage: chkpath ^<path^>
echo checks if path element is included in path variable.
echo returns 1 if yes, 2 if no, 0 if not checked.
echo.
goto END
--------------------------------------------
:END
call :CleanUp
:ReallyEnd
endlocal & set errorlevel=%rc%
@REM set errorlevel=%rc%
@REM echo %errorlevel%
lpath.bat:
@echo.
@set curdrive=%~d0
@REM This form post-fixes a | at the end of each path element. Useful for debugging trailing spaces.
@REM @path | %curdrive%\cygwin\bin\sed.exe -e s/PATH=// -e 's/;/^|\n/g' -e 's/$/^|/g'
@REM This form shows bare path elements.
@REM @path | %curdrive%\cygwin\bin\sed.exe -e 's/PATH=//' -e 's/;/^\n/g'
@path | %curdrive%\utils\sed -e "s/PATH=//" | %curdrive%\utils\tr ; \n
@echo.