Spawning a new process
In this recipe, we will see how to spawn a new process using ProcessBuilder
. We will also see how to make use of the input, output, and error streams. This should be a very straightforward and common recipe. However, the aim of introducing this is to make this chapter a bit more complete and not just to focus on Java 9 features.
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Getting ready
There is a command in Linux called free
, which shows the amount of RAM that is free and how much is being used by the system. It accepts an option, -m
, to show the output in megabytes. So, just running free -m
gives us the following output:Â
We will be running the preceding code from within the Java program.
How to do it...
Follow these steps:
- Create an instance of
ProcessBuilder
by providing the required command and its options:Â
ProcessBuilder pBuilder = new ProcessBuilder("free", "-m");
An alternative way to specify the command and options is as follows:
pBuilder.command("free", "-m");
- Set up the input and output streams...