Meaning of the pstree output

Question

-bash-3.2$ pstree 27108
Script.sh---java---15*[{java}]

What does this 15* mean here, also any meanings defined for [] & {} in the context of command?

Answer 1

Its right there in the man page:

   pstree shows running processes as a tree. The tree is rooted at either pid or init
   if pid is omitted. If a user name is specified, all process trees rooted  at  pro-
   cesses owned by that user are shown.

   pstree  visually  merges identical branches by putting them in square brackets and
   prefixing them with the repetition count, e.g.

       init-+-getty
            |-getty
            |-getty
            ‘-getty

   becomes

       init---4*[getty]

   Child threads of a process are found under the parent process and are  shown  with
   the process name in curly braces, e.g.

       icecast2---13*[{icecast2}]

In your case, the process 27108 was started by the script Script.sh. The Script.sh created a java process which spawned another 15 java threads.

A ps -eLf | grep java | wc -l should returned you a count around the number 15.

Answer 2

man pstree:

  pstree visually merges identical branches by putting them in square brackets and prefixing them with the repetition count, e.g.

       init-+-getty
            |-getty
            |-getty
            `-getty

   becomes

       init---4*[getty]

   Child threads of a process are found under the parent process and are shown with the process name in curly braces, e.g.

       icecast2---13*[{icecast2}]

So, 15 threads of java process.