get Hard Link Count in Java

Question

I need something to get the hard link count from a file in a solaris10 os in java.

parsing ls -l is not an option.

I tried using posix for java http://bmsi.com/java/posix/index.html but couldn't manage to get it working.

Is there any other lightweight API or code to get this info?

Answer 1

In Java 7 you can use the new file attributes API to get it with java.nio.file.Files.getAttribute(path, "unix:nlink").

The "unix" attribute view is not actually defined as part of the standard API (and the "posix" view does not give you nlink), but is available in the standard Oracle/OpenJDK implementation. On the other hand creating a link is now available with the standard createLink method on Files. Go figure.

Answer 2

Short of using JNI and stat/lstat in C the only thing better than parsing ls would be to run:

stat --format=%h filename

which just outputs a number and is easy to parse.

But it all gets complicated when there can be non-ascii characters in filenames. You'd need to convert filename to native encoding, and sometimes not all characters allowed in filename can be converted (if native encoding isn't some kind of unicode).

Answer 3

Also consider trying the jnr-posix implementation of stat(2) for this.