I modified the detection of delayed expansion to use COMSPEC instead of OS. I did this because I think it is less likely that an environment will have purged the COMSPEC variable, since pipes cannot work unless it is properly defined. I'm not aware of any batch dependencies on OS, so someone could conceivably clear the definition of OS.
EXCEPTION.BAT Version 1.2
Code: Select all
::EXCEPTION.BAT Version 1.2
::
:: Provides exception handling for Windows batch scripts.
::
:: Designed and written by Dave Benham, with important contributions from
:: DosTips users jeb and siberia-man
::
:: Full documentation is at the bottom of this script
::
:: History:
:: v1.2 2015-07-16 Use COMSPEC instead of OS to detect delayed expansion
:: v1.1 2015-07-03 Preserve ! in exception attributes when delayed expansion enabled
:: v1.0 2015-06-26 Initial versioned release with embedded documentation
::
@echo off
if "%~1" equ "/?" goto help
if "%~1" equ "" goto help
shift /1 & goto %1
:throw errCode errMsg errLoc
set "exception.Stack="
:: Fall through to :rethrow
:rethrow errCode errMsg errLoc
setlocal disableDelayedExpansion
if not defined exception.Restart set "exception.Stack=[%~1:%~2] %exception.Stack%"
for /f "delims=" %%1 in ("%~1") do for /f "delims=" %%2 in ("%~2") do for /f "delims=" %%3 in ("%~3") do (
setlocal enableDelayedExpansion
for /l %%# in (1 1 10) do for /f "delims=" %%S in (" !exception.Stack!") do (
(goto) 2>NUL
setlocal enableDelayedExpansion
if "!!" equ "" (
endlocal
setlocal disableDelayedExpansion
call set "funcName=%%~0"
call set "batName=%%~f0"
if defined exception.Restart (set "exception.Restart=") else call set "exception.Stack=%%funcName%%%%S"
setlocal EnableDelayedExpansion
if !exception.Try! == !batName!:!funcName! (
endlocal
endlocal
set "exception.Code=%%1"
if "!!" equ "" (
call "%~f0" setDelayed
) else (
set "exception.Msg=%%2"
set "exception.Loc=%%3"
set "exception.Stack=%%S"
)
set "exception.Try="
(CALL )
goto :@Catch
)
) else (
for %%V in (Code Msg Loc Stack Try Restart) do set "exception.%%V="
if "!comspec!" equ "%comspec%" (
call "%~f0" showDelayed
) else (
echo(
echo Unhandled batch exception:
echo Code = %%1
echo Msg = %%2
echo Loc = %%3
echo Stack=%%S
)
echo on
call "%~f0" Kill
)>&2
)
set exception.Restart=1
setlocal disableDelayedExpansion
call "%~f0" rethrow %1 %2 %3
)
:: Never reaches here
:init
set "@Try=call set exception.Try=%%~f0:%%~0"
set "@EndTry=set "exception.Try=" & goto :@endCatch"
:: Fall through to :clear
:clear
for %%V in (Code Msg Loc Stack Restart Try) do set "exception.%%V="
exit /b
:Kill - Cease all processing, ignoring any remaining cached commands
setlocal disableDelayedExpansion
if not exist "%temp%\Kill.Yes" call :buildYes
call :CtrlC <"%temp%\Kill.Yes" 1>nul 2>&1
:CtrlC
@cmd /c exit -1073741510
:buildYes - Establish a Yes file for the language used by the OS
pushd "%temp%"
set "yes="
copy nul Kill.Yes >nul
for /f "delims=(/ tokens=2" %%Y in (
'"copy /-y nul Kill.Yes <nul"'
) do if not defined yes set "yes=%%Y"
echo %yes%>Kill.Yes
popd
exit /b
:setDelayed
setLocal disableDelayedExpansion
for %%. in (.) do (
set "v2=%%2"
set "v3=%%3"
set "vS=%%S"
)
(
endlocal
set "exception.Msg=%v2:!=^!%"
set "exception.Loc=%v3:!=^!%"
set "exception.Stack=%vS:!=^!%"
)
exit /b
:showDelayed -
setLocal disableDelayedExpansion
for %%. in (.) do (
set "v2=%%2"
set "v3=%%3"
set "vS=%%S"
)
for /f "delims=" %%2 in ("%v2:!=^!%") do for /f "delims=" %%3 in ("%v3:!=^!%") do for /f "delims=" %%S in ("%vS:!=^!%") do (
endlocal
echo(
echo Unhandled batch exception:
echo Code = %%1
echo Msg = %%2
echo Loc = %%3
echo Stack=%%S
)
exit /b
:-?
:help
setlocal disableDelayedExpansion
for /f "delims=:" %%N in ('findstr /rbn ":::DOCUMENTATION:::" "%~f0"') do set "skip=%%N"
for /f "skip=%skip% tokens=1* delims=:" %%A in ('findstr /n "^" "%~f0"') do echo(%%B
exit /b
:-v
:/v
:version
echo(
for /f "delims=:" %%A in ('findstr "^::EXCEPTION.BAT" "%~f0"') do echo %%A
exit /b
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
:::DOCUMENTATION:::
EXCEPTION.BAT is a pure batch script utility that provides robust exception
handling within batch scripts. It enables code to be placed in TRY/CATCH blocks.
If no exception is thrown, then only code within the TRY block is executed.
If an exception is thrown, the batch CALL stack is popped repeatedly until it
reaches an active TRY block, at which point control is passed to the associated
CATCH block and normal processing resumes from that point. Code within a CATCH
block is ignored unless an exception is thrown.
An exception may be caught in a different script from where it was thrown.
If no active TRY is found after throwing an exception, then an unhandled
exception message is printed to stderr, all processing is terminated within the
current CMD shell, and control is returned to the shell command line.
TRY blocks are specified using macros. Obviously the macros must be defined
before they can be used. The TRY macros are defined using the following CALL
call exception init
Besides defining @Try and @EndTry, the init routine also explicitly clears any
residual exception that may have been left by prior processing.
A TRY/CATCH block is structured as follows:
%@Try%
REM any normal code goes here
%@EndTry%
:@Catch
REM exception handling code goes here
:@EndCatch
- Every TRY must have an associated CATCH.
- TRY/CATCH blocks cannot be nested.
- Any script or :labeled routine that uses TRY/CATCH must have at least one
SETLOCAL prior to the appearance of the first TRY.
- TRY/CATCH blocks use labels, so they should not be placed within parentheses.
It can be done, but the parentheses block is broken when control is passed to
the :@Catch or :@EndCatch label, and the code becomes difficult to interpret
and maintain.
- Any valid code can be used within a TRY or CATCH block, including CALL, GOTO,
:labels, and balanced parentheses. However, GOTO cannot be used to leave a
TRY block. GOTO can only be used within a TRY block if the label appears
within the same TRY block.
- GOTO must never transfer control from outside TRY/CATCH to within a TRY or
CATCH block.
- CALL should not be used to call a label within a TRY or CATCH block.
- CALLed routines containing TRY/CATCH must have labels that are unique within
the script. This is generally good batch programming practice anyway.
It is OK for different scripts to share :label names.
- If a script or routine recursively CALLs itself and contains TRY/CATCH, then
it must not throw an exception until after execution of the first %@Try%
Exceptions are thrown by using
call exception throw Code Message Location
where
Code = The numeric code value for the exception.
Message = A description of the exception.
Location = A string that helps identify where the exception occurred.
Any value may be used. A good generic value is "%~f0[%~0]",
which expands to the full path of the currently executing
script, followed by the currently executing routine name
within square brackets.
The Message and Location values must be quoted if they contain spaces or poison
characters like & | < >. The values must not contain additional internal quotes,
and they must not contain a caret ^.
The following variables will be defined for use by the CATCH block:
exception.Code = the Code value
exception.Msg = the Message value
exception.Loc = the Location value
exception.Stack = traces the call stack from the CATCH block (or command line
if not caught), all the way to the exception.
If the exception is not caught, then all four values are printed as part of the
"unhandled exception" message, and the exception variables are not defined.
A CATCH block should always do ONE of the following at the end:
- If the exception has been handled and processing can continue, then clear the
exception definition by using
call exception clear
Clear should never be used within a Try block.
- If the exception has not been fully handled, then a new exception should be
thrown which can be caught by a higher level CATCH. You can throw a new
exception using the normal THROW, which will clear exception.Stack and any
higher CATCH will have no awareness of the original exception.
Alternatively, you may rethrow an exception and preserve the exeption stack
all the way to the original exception:
call exception rethrow Code Message Location
It is your choice as to whether you want to pass the original Code and/or
Message and/or Location. Either way, the stack will preserve all exceptions
if rethrow is used.
Rethrow should only be used within a CATCH block.
One last restriction - the full path to EXCEPTION.BAT must not include ! or ^.
This documentation can be accessed via the following command
exception help
The version of this utility can be accessed via
call exception version
EXCEPTION.BAT was designed and written by Dave Benham, with important
contributions from DosTips users jeb and siberia-man.
Development history can be traced at:
http://www.dostips.com/forum/viewtopic.php?f=3&t=6497
Dave Benham