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javacmdprocessbuilder

ProcessBuilder and cmd

Why does 

ProcessBuilder pb = new ProcessBuilder("cmd","/C","dir");

work but 

ProcessBuilder pb = new ProcessBuilder("cmd","dir");

does not.
I mean in the latter case the cmd starts but the listing of the directory does not happen.Why is this?

Solution

  • It is the normal behaviour of cmd.exe - the same happens on the command line:

    C:\>cmd dir
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

    C:\>cmd /c dir
 Volume in drive C is System
 Volume Serial Number is ABCD-EF10
...

    With the first call, you are creating a new (interactive) command interpreter process, cmd.exe. With the second call, you are creating a new command interpreter process and tell it to execute the given command and then exit:

    /C      Carries out the command specified by string and then terminates