Is it a standard command that I can be assured is available on all standard-conformant operating systems? If so, what is the guarantee given by the relevant standard?

Is it, conversely, a non-standard command that is nonetheless widely available?

On what (Unix and Linux, of course) operating systems can I find a pstree command available, either as part of the operating system or as a package from the operating system's normal package repositories?

  • The package that pstree is typically included in is psmisc - pkgs.org/download/psmisc. It's intrinsically difficult to determine if utility X is installed by default on *ixes Y.
    – slm
    Commented Jul 27, 2018 at 1:46
  • It’s a good edit to the question, but I fear would have too broad an answer as time goes on. It’s the last question in the Question that pushes it over the edge for me.
    – Jeff Schaller
    Commented Jul 28, 2018 at 13:29
  • JdeBP thanks for the edit. @JeffSchaller I don’t mind browsing through every distribution’s docs to find out if this exists, but for the most common utilities, I kinda sense that there is some spec/convention being followed. My initial question was intended to find that. Do you think if the last question can be edited to ask the former, it might fit your criteria?
    – Sam Thomas
    Commented Jul 28, 2018 at 16:09
  • In my opinion, the best chance of specific question that can be concretely answered would be to ask which of these (X,Y,Z) current distributions include pstree in a default installation. I wouldn't expect an answerer to survey the hundreds (thousands?) of distributions, nor would I expect an answer to cover future distributions or ones that change their mind at some point. (1/2)
    – Jeff Schaller
    Commented Jul 30, 2018 at 11:25
  • 1
    Also, you might consider whether a random UNIX variant has come up with their own pstree command that takes different options and/or does different things -- in which case you might want to specify which exact pstree you're curious about -- on the assumption that you're distributing a script that depends on certain pstree behavior.
    – Jeff Schaller
    Commented Jul 30, 2018 at 11:26

1 Answer 1


It's on Linux distros by default, on AIX or whatever you'd need to install/compile it.

  • Is there a place I can refer incase I need to find out about commands other than pstree? Also since you have enough reputation, could you please tage this question with pstree rather than ps? Thanks
    – Sam Thomas
    Commented Jul 27, 2018 at 0:28

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