check if command was successful in a batch file

Question

How within a batch file to check if command  start    javaw -jar   p0 example jar   was successful or produced an error   I want to use if else statements to echo this info out

User · Accepted Answer

You can use  if errorlevel 1 echo Unsuccessful   in some cases  This depends on the last command returning a proper exit code  You won t be able to tell that there is anything wrong if your program returns normally even if there was an abnormal condition   Caution with programs like Robocopy  which require a more nuanced approach  as the error level returned from that is a bitmask which contains more than just a boolean information and the actual success code is  AFAIK  3

User · Answer

Most commands programs return a 0 on success and some other value  called errorlevel  to signal an error   You can check for this in you batch for example by   call  lt THE COMMAND HERE gt  if  ERRORLEVEL     0 goto  next echo  Errors encountered during execution   Exited with status   errorlevel   goto  endofscript   next echo  Doing the next thing    endofscript echo  Script complete

User · Answer

I don t know if javaw will write to the  errorlevel  variable  but it might    echo  errorlevel  after you run it directly to see   Other than that  you can pipe the output of javaw to a file  then use find to see what the results were  Without knowing the output of it  I can t really help you with that

User · Answer

This likely doesn t work with start  as that starts a new window  but to answer your question   If the command returns a error level you can check the following ways  By Specific Error Level  commandhere if  errorlevel   131 echo do something   By If Any Error  commandhere    echo what to do if error level ISN T 0   By If No Error  commandhere  amp  amp  echo what to do if error level IS 0   If it does not return a error level but does give output  you can catch it in a variable and determine by the output  example  note the tokens and delims are just examples and would likely fail with any special characters   By Parsing Full Output  for  f  tokens   delims     a in   somecommand   do set output   a if  output   whateveritwouldsayinerror echo error   Or you could just look for a single phrase in the output like the word Error  By Checking For String      commandhere   find  Error     echo There was no error  commandhere   find  Error   amp  amp  echo There was an error    And you could even mix together  just remember to escape   with    if in a for statement   Hope this helps

User · Answer

Goodness I had a hard time finding the answer to this    Here it is   cd thisDoesntExist if  errorlevel     0     echo Oh  I guess it does   echo Huh

[batch-file] check if command was successful in a batch file

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