The process-tree script presented in this chapter does exactly what its name suggests: it prints out the names of some or all of the currently running processes that are present in the process table, displaying the parent/child relationships that exist among them in the form of a visual tree. There is an implementation of this functionality on some versions of Solaris (ptree) and on all flavors of Linux (pstree). These have proved very valuable to me for finding the root of a process group quickly, especially when that part of the process tree needs to be shut down.