Batch Files Error Handling
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Error Checking In Batch Script
hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss batch script catch error Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Batch Programming, Error Handling, batch file error handling tutorial and Start Command up vote 6 down vote favorite I am just starting to learn how to script. I'm trying to understand how the system handles Error Levels and how they can be used in error handling. I know there is a difference between the environment variable %ERRORLEVEL% and the Error Level of the system. If I understand this correctly, then the If ERRORLEVEL 1
Batch File Error Handling Errorlevel
code would check the environment variable before it checks the error level of the previous command. So, in my program I am trying to interface a startup/stop script that will start/stop all scripts of a given machine (for testing I'm just using one application notepad.exe as an example). I have two wrapper scripts that will either start up or stop the applications by passing arguments to the independent script. If there is an error in the independent script, it will set the errorlevel using the EXIT /B n command. Once control is returned to the calling script, it will go to an error handling script if the exit status is non-zero. At first I was setting the %ERRORLEVEL% to zero manually and then testing for an error after a START or TASKKILL command. But then I read that clearing %ERRORLEVEL% with SET ERRORLEVEL= is a better method. My issue comes in when I try to start the app with START "" notepad.exe Whenever I test the errorlevel after this command it is always greater than or equal to 1 unless I use SET ERRORLEVEL=0 before I run the start command. I have inserte
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Try Catch Batch File
programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Does Windows batch support exception handling? up vote 13 down vote favorite 7 Does Windows batch programming support exception handling? http://stackoverflow.com/questions/6498460/batch-programming-error-handling-and-start-command If not, is there any way to effectively emulate exception handling within batch files? I would like to be able to "throw an exception" anywhere within a batch script, at any CALL level, and have the CALL stack popped repeatedly until it finds an active "TRY block", whereupon a "CATCH block" can handle the exception fully and carry on, or do some cleanup and continue popping the CALL stack. If the exception is http://stackoverflow.com/questions/31445330/does-windows-batch-support-exception-handling never handled, then batch processing is terminated and control returns to the command line context with an error message. There are already couple posted ways to terminate batch processing at any CALL depth, but none of those techniques allow for any structured cleanup activity that would normally be provided within other languages via exception handling. Note: This is a case where I already know a good answer that has only recently been discovered, and I want to share the info batch-file exception exception-handling cmd share|improve this question asked Jul 16 '15 at 4:24 dbenham 77.7k11114179 add a comment| 2 Answers 2 active oldest votes up vote 14 down vote accepted Windows batch scripting certainly does not have any formal exception handling - hardly surprising considering how primitive the language is. Never in my wildest dreams did I ever think effective exception handling could be hacked up. But then some amazing discoveries were made on a Russian site concerning the behavior of an erroneous GOTO statement (I have no idea what is said, I can't read Russian). An English summary was posted at DosTips, and the behavior was further investigated. It turns out that (GOTO) 2>NUL behaves almost identically to EXIT /B, except concatenated commands within an already parsed block of code are still executed after the effective
Checking and Running as Scheduled Tasks ★★★★★★★★★★★★★★★ Paul Adams (ex-MSFT)June 6, 201016 0 0 0 Batch files may be considered “old hat” by a lot of people (or a complete mystery to the younger ones!) https://blogs.technet.microsoft.com/mrsnrub/2010/06/06/batch-files-basic-error-checking-and-running-as-scheduled-tasks/ but they are sometimes still the easiest way to execute simple jobs as they have practically no requirements other than a command shell process to run within – yes there is a strong probability that a http://www.robvanderwoude.com/errorlevel.php script could achieve an identical (or at least equivalent) result, but the fact is that it will be more complex and therefore longer to create and administer. Something that trips up a fair number of people error handling is the difference between double-clicking a .BAT file and scheduling it as a task to run at a certain time, on a trigger or on a schedule – it can seem that the batch file just simply does not run at all, and the return code sent back to the Task Scheduler is often 0x2, “path not found”, even though the file most definitely is there. When you double-click a .BAT batch file error or .CMD file through Explorer, a cmd.exe process is started to provide the environment in which it will run. The credentials used are your own (or more correctly, inherited from the Explorer process). The “current working directory” is set to that where the batch file lives. When the Task Scheduler service starts the same batch file it actually invokes an instance of cmd.exe (as SYSTEM impersonating the user whose credentials are defined in the task) to carry out the process and waits for it to exit with a return code – the current working directory for this process is not that of the batch file, but that of cmd.exe itself. i.e. %windir%\system32 Now, if your batch file assumes that you launched it through Explorer or from an existing command prompt with the current working directory set to its own location, you can run into problems. One simple way to verify if your batch file should work as a scheduled task is to call it from an existing cmd.exe process from a different current working directory (such as your profile, or a temp folder). Be very, very careful if your batch file does any kind of file deletion – especially if wildcards are involved – you do not want to be in the wr
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