errorlevel

问题 I think i have a basic understanding of ERRORLEVEL vs %ERRORLEVEL% but !ERRORLEVEL! confuses me. I'm making a script that calls an executable, then tasklist to see if its running, then taskkill to kill it if it is and then trying to output the errorlevels and repeating for other exe's and i'm realising i really don't understand errorlevels in batch. I set a variable equal to !errorlevel! then used that variable without quotation marks in an echo, and the variable changed from one uint16 to

问题 Just stumbled into a weird thing with %ERRORLEVEL% and wanted to see if anyone knows why and if there's a way to fix it. Essentially, it seems as if commands executed inside if statements don't set the %ERRORLEVEL% variable. The ERRORLEVEL (as in IF ERRORLEVEL 1 , which is different from IF %ERRORLEVEL% EQU 1 ) check seems to still work fine though, so I can probably work around it, but it would still be nice to be able to print the error level. For debugging or whatever. @echo off Set

问题 A frequent method to handling errors within Windows batch scripts is to use things like if errorlevel 1 ... or if %errorlevel% neq 0 ... . Often times one wants the error handling code to preserve the ERRORLEVEL. I believe all external commands will always result in ERRORLEVEL being set to some value, so the error handling code must preserve the ERRORLEVEL in an environment variable prior to executing an external command. But what about internal commands? The problem is, some internal

问题 The ERRORLEVEL is a value returned by most cmd.exe commands when they end that change depending on a series of conditions, so knowing the value that the commands return is valuable information that may aid to write better Batch files. All external .exe programs change the ERRORLEVEL when they end (that is an inherent mechanism of both ExitProcess and TerminateProcess Win-32 API functions) and usually such values are documented, but the values returned by internal cmd.exe commands are not