Shell (bash) brace expansion with Java's runtime.exec

Question

I'm trying to get an expansion command to work with runtime.exec, but the braces are being interpreted as literals rather than being expanded. Here's what I'm trying to do:

String command = "mkdir -p Foldername{1,2,3}/InnerFolder";
Runtime.getRuntime().exec( new String[] { "sh", "-c", command } );

Unfortunately, that gives me a single folder in my current directory named "Foldername{1,2,3}" instead of "Foldername1", "Foldername2", and "Foldername3". Does anyone know of a way to prevent the braces from being interpreted as literals?

Answer 1

You're trying to use Bash wildcards. They are interpreted within the Bash shell. You are running mkdir directly, so there is no shell to interpret {}. You need to specify path to the shell

String command = "mkdir -p Foldername{1,2,3}/InnerFolder";
Runtime.getRuntime().exec( new String[] { "/bin/bash", "-c", command } );

Source.