Redirecting the process output and error streams to file

In this recipe, we will see how to deal with the output and error streams of a process spawned from the Java code. We will write the output or error produced by the spawned process to a file. 

 

 

Getting ready

In this recipe, we will make use of the iostat command. This command is used for reporting the CPU and I/O statistics for different devices and partitions. Let's run the command and see what it reports:

$ iostat

Note

In some Linux distributions, such as Ubuntu, iostat is not installed by default. You can install the utility by running sudo apt-get install sysstat.

The output of the preceding command is as follows:

How to do it...

Follow these steps:

1. Create a new ProcessBuilder object by specifying the command to be executed:

        ProcessBuilder pb = new ProcessBuilder("iostat");

2. Redirect the output and error streams to the file's output and error, respectively:

        pb.redirectError(new File("error"))
          .redirectOutput(new File...