% ps-etc -- pstree & friends for Linux, FreeBSD & MacOS.
% Jessica L. Parsons <orc@pell.portland.or.us>
% Wed Jan 16 01:36:26 PST 2008
#pstree

**Pstree** is a clone of the standard Linux pstree command, which displays
process information in a heirarchical fashion.   It builds and runs on
SLS linux, RedHat linux (tested rhel3,centos 7), Debian linux,
[FreeBSD](http://www.freebsd.org) (tested on 4.4 & 4.8,)
[MacOS](http://www.apple.com/macosx) 10.4 through 10.12, and
[Minix 3](http://www.minix3.org).   Unlike the
standard pstree, it uses either `sysctl()` [macOS], `kvm_getprocs()`
[FreeBSD 4.?] or `/proc` [SLS linux] as needed.

**pstree** is free software;  it is released under a
[BSD-style license](ps-etc-current/COPYRIGHT)
that allows you to do as you wish with it as long as you don't attempt
to claim it as your own work.

To install pstree, do

	$ ./configure.sh
	$ make

then become root and do

	# make install

If pstree needs to use `sysctl()` or `kvm_getprocs()` to read process
information, it will be installed as a setuid process to allow
it to read all of the process data.

##Source Code

=[v0.7](ps-etc-0.7.tar.bz2)=
    A small handful of tweaks to catch up to changes in MacOS (`echo`
    bit me again, so I modified `configure.inc` to generate a local
    echo command that does echo -n properly),  support for Minix 3.3
    (new `/proc` filesystem support), and a couple of bugfixes to deal
    with zero-length command lines.)

=[v0.6](ps-etc-0.6.tar.bz2)=
    FreeBSD 7.1 changed some of its kernel data structures, which
    made the whole `kvm_`... world just stop working.   After extensive
    work with `grep`, I figured out what had become of them and modified
    ps-etc to work here.

    And then I found a bug in the BSD support, in that if a process
    modified its command line, those changes wouldn't show up in
    `pstree -a`. It turns out that modified command lines end up in
    `argv[0]`, which I was clipping off in favor of the `kinfo_proc`
    process name.   So I had to redo that code to use `argv[0]` instead,
    and as a side-effect of that I was able to track changes in command
    names, so I can do the same thing that FreeBSD does with `ps -a` and
    put a `(command)` suffix onto the output if `argv[0]` was actually
    changed.

    ->\*whew!\*<-

    On top of all that, I modified the way commandlines are printed to
    have embedded spaces display as spaces instead of `\040` -- the
    `-s` option disables that new feature if you wish to see the old
    behavior.

=[v0.5](ps-etc-0.5.tar.gz)=
    `basename()` on the BSDs uses a static buffer to hold the new
    basename.  This makes it pretty much impossible to use `basename()`
    for anything non-trivial unless you surround it with a `strdup()`
    wrapper.   The 0.5 release corrects this misfeature by replacing
    `basename()` with a local function.

=[v0.4](ps-etc-0.4.tar.gz)=
    1.  Internal range checking to take away the fun of having a setuid
        program possibly doing a stack overrun and giving J. Random.
        Hacker a free doorway to root privileges.
    2.  [<s>Implement the **`-A`**
        option (like **`-a`**, except it shows, if possible, the full
        pathname to the program name.)  </s>](abbr:mysteriously disappeared in version 0.5!)
    3.  Try to automatically configure whether to look at `/proc` or use
        `sysctl()` or `kvm_getprocs()`.

=[v0.3](ps-etc-0.3.tar.gz)=
    A [README](ps-etc-current/README) file, support for the **`-l`**
    option, automatic window width detection, more work on `sysctl()`
    vs `kvm_getprocs()` so that it will work on FreeBSD versions that
    don't support `kvm_getprocs()` anymore.

=[v0.2](ps-etc-0.2.tar.gz)=
    The first release that works on more than one platform; 0.2
    works on FreeBSD 4.x and SLS linux, and doesn't have an embarrassing
    number of misfeatures and/or bugs.

=[v0.1](ps-etc-0.1.tar.gz)=
    The initial release, which almost works on SLS linux.