[Lazarus] Process ID

Mark Morgan Lloyd markMLl.lazarus at telemetry.co.uk
Thu Sep 13 11:04:22 CEST 2012

Kaj Mikkelsen wrote:

> I have never seen a Linux or Unix system that did not have ps installed.

No, but I've seen it not working because /proc wasn't available- which 
gives you absolutely no advantage attempting to use ps compared with 
going to /proc directly (i.e. you get an unparseable error message from 
ps compared with a clear indication that there's nothing mounted on /proc).

> Unless we are talking embedded systems or similar.
> Unix systems (Solaris, AIX, SCO ) do not have the /proc file system, at
> least it is not usable.

Wrong. I've got a terminal session connected to a Solaris 10 system on 
my desk at the moment (because I'm trying to debug some LOM issues), and 
/proc is fine. However, it's worth remembering that non-Linux 
implementations tend to have less in the /proc tree than Linux, and that 
the Linux kernel developers are trying to move towards this model.

I would say that Solaris appears not to have /proc/nnn/cmdline, I think 
the equivalent is in /proc/nnn/psinfo. Irrespective of which, I still 
think it's better practice to either go directly to /proc or to look for 
a portable library- I don't know whether there's a POSIX API for this in 
the same way that there's a POSIX-compliant capabilities library on top 
of the Linux/Solaris/etc. kernel.

Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

[Opinions above are the author's, not those of his employers or colleagues]

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