ENDLOCAL & SET VAR=%TEMPVAR% 模式是经典的。但也有不理想的情况。
如果您不知道 TEMPVAR 的内容，那么如果该值包含特殊字符，例如 < > & 或|，您可能会遇到问题。您通常可以使用 SET "VAR=%TEMPVAR%" 之类的引号来防止这种情况发生，但如果存在特殊字符并且值已被引用，则可能会导致问题。
如果您担心特殊字符，则 FOR 表达式是跨 ENDLOCAL 屏障传输值的绝佳选择。延迟扩展应在 ENDLOCAL 之前启用，在 ENDLOCAL 之后禁用。
setlocal enableDelayedExpansion
set "TEMPVAR=This & "that ^& the other thing"
for /f "delims=" %%A in (""!TEMPVAR!"") do endlocal & set "VAR=%%~A"
限制：
如果您必须返回多个值，并且您知道某个字符不能出现在任一值中，则只需使用适当的 FOR /F 选项。例如，如果我知道这些值不能包含|：
setlocal enableDelayedExpansion
set "temp1=val1"
set "temp2=val2"
for /f "tokens=1,2 delims=|" %%A in (""!temp1!"|"!temp2!"") do (
endLocal
set "var1=%%~A"
set "var2=%%~B"
)
如果必须返回多个值，并且字符集不受限制，则使用嵌套的 FOR /F 循环：
setlocal enableDelayedExpansion
set "temp1=val1"
set "temp2=val2"
for /f "delims=" %%A in (""!temp1!"") do (
for /f "delims=" %%B in (""!temp2!"") do (
endlocal
set "var1=%%~A"
set "var2=%%~B"
)
)
请务必查看jeb's answer，了解适用于所有情况下所有可能值的安全、防弹技术。
2017-08-21 - 新功能 RETURN.BAT
我与 DosTips 用户 jeb 合作开发了a batch utility called RETURN.BAT，它可用于退出脚本或调用例程，并通过 ENDLOCAL 屏障返回一个或多个变量。非常酷:-)
以下是 3.0 版的代码。我很可能不会让这段代码保持最新。最好点击链接以确保您获得最新版本，并查看一些示例用法。
RETURN.BAT
::RETURN.BAT Version 3.0
@if "%~2" equ "" (goto :return.special) else goto :return
:::
:::call RETURN ValueVar ReturnVar [ErrorCode]
::: Used by batch functions to EXIT /B and safely return any value across the
::: ENDLOCAL barrier.
::: ValueVar = The name of the local variable containing the return value.
::: ReturnVar = The name of the variable to receive the return value.
::: ErrorCode = The returned ERRORLEVEL, defaults to 0 if not specified.
:::
:::call RETURN "ValueVar1 ValueVar2 ..." "ReturnVar1 ReturnVar2 ..." [ErrorCode]
::: Same as before, except the first and second arugments are quoted and space
::: delimited lists of variable names.
:::
::: Note that the total length of all assignments (variable names and values)
::: must be less then 3.8k bytes. No checks are performed to verify that all
::: assignments fit within the limit. Variable names must not contain space,
::: tab, comma, semicolon, caret, asterisk, question mark, or exclamation point.
:::
:::call RETURN init
::: Defines return.LF and return.CR variables. Not required, but should be
::: called once at the top of your script to improve performance of RETURN.
:::
:::return /?
::: Displays this help
:::
:::return /V
::: Displays the version of RETURN.BAT
:::
:::
:::RETURN.BAT was written by Dave Benham and DosTips user jeb, and was originally
:::posted within the folloing DosTips thread:
::: http://www.dostips.com/forum/viewtopic.php?f=3&t=6496
:::
::==============================================================================
:: If the code below is copied within a script, then the :return.special code
:: can be removed, and your script can use the following calls:
::
:: call :return ValueVar ReturnVar [ErrorCode]
::
:: call :return.init
::
:return ValueVar ReturnVar [ErrorCode]
:: Safely returns any value(s) across the ENDLOCAL barrier. Default ErrorCode is 0
setlocal enableDelayedExpansion
if not defined return.LF call :return.init
if not defined return.CR call :return.init
set "return.normalCmd="
set "return.delayedCmd="
set "return.vars=%~2"
for %%a in (%~1) do for /f "tokens=1*" %%b in ("!return.vars!") do (
set "return.normal=!%%a!"
if defined return.normal (
set "return.normal=!return.normal:%%=%%3!"
set "return.normal=!return.normal:"=%%4!"
for %%C in ("!return.LF!") do set "return.normal=!return.normal:%%~C=%%~1!"
for %%C in ("!return.CR!") do set "return.normal=!return.normal:%%~C=%%2!"
set "return.delayed=!return.normal:^=^^^^!"
) else set "return.delayed="
if defined return.delayed call :return.setDelayed
set "return.normalCmd=!return.normalCmd!&set "%%b=!return.normal!"^!"
set "return.delayedCmd=!return.delayedCmd!&set "%%b=!return.delayed!"^!"
set "return.vars=%%c"
)
set "err=%~3"
if not defined err set "err=0"
for %%1 in ("!return.LF!") do for /f "tokens=1-3" %%2 in (^"!return.CR! %% "") do (
(goto) 2>nul
(goto) 2>nul
if "^!^" equ "^!" (%return.delayedCmd:~1%) else %return.normalCmd:~1%
if %err% equ 0 (call ) else if %err% equ 1 (call) else cmd /c exit %err%
)
:return.setDelayed
set "return.delayed=%return.delayed:!=^^^!%" !
exit /b
:return.special
@if /i "%~1" equ "init" goto return.init
@if "%~1" equ "/?" (
for /f "tokens=* delims=:" %%A in ('findstr "^:::" "%~f0"') do @echo(%%A
exit /b 0
)
@if /i "%~1" equ "/V" (
for /f "tokens=* delims=:" %%A in ('findstr /rc:"^::RETURN.BAT Version" "%~f0"') do @echo %%A
exit /b 0
)
@>&2 echo ERROR: Invalid call to RETURN.BAT
@exit /b 1
:return.init - Initializes the return.LF and return.CR variables
set ^"return.LF=^
^" The empty line above is critical - DO NOT REMOVE
for /f %%C in ('copy /z "%~f0" nul') do set "return.CR=%%C"
exit /b 0