Collect Linux command output

Question

I am now on a linux machine. I have a Java program which would run some linux command, for example ps, top, list or free -m.

The way to run a command in Java is as follows:

Process p = Runtime.getRuntime().exec("free -m");

How could I collect the output by Java program? I need to process the data in the output.

Answer 1

Use Process.getInputStream() to get an InputStream that represents the stdout of the newly created process.

Note that starting/running external processes from Java can be very tricky and has quite a few pitfalls.

They are described in this excellent article, which also describes ways around them.