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Re: Default PATH setting - reduce to something more sensible?

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scott@slp53.sl.home (Scott Lurndal) writes:
> Rainer Weikusat <rweikusat@talktalk.net> writes:
>>Janis Papanagnou <janis_papanagnou+ng@hotmail.com> writes:
>>> When I recently inspected an 'strace' log and saw the huge amount
>>> of system-calls done for a simple standard command (like 'rm') -
>>> it's more than a dozen! and most lead just to ENOENT - I wondered
>>> about the default PATH definition which is for my system
>>>   /usr/lib/lightdm/lightdm
>>>   /usr/local/sbin
>>>   /usr/local/bin
>>>   /usr/sbin
>>>   /usr/bin
>>>   /sbin
>>>   /bin
>>>   /usr/games
>>> (here I'm omitting my own additions, '~/bin' and '.', and I separated
>>> them, one on each line for a better visualization of the "problem" or,
>>> maybe better, for the "questions".)
>>>
>>> The above PATH components are for a terminal running under some
>>> window manager, a plain console window will not show the 'lightdm'
>>> entry (but I rarely work on plain consoles).
>>>
>>> This raises a few questions, and someone may shed some light on the
>>> rationale for above default settings... (and how to "fix" it best)
>>
>>Why do you want to change that? At worst, this will make seven execve to
>>execute binary. Usually, it will rather be 4. That's not going to take a
>>noticeable amount of time.
>>
>>As far as I could determine, some sort of path searching has existed
>>since the 6th edition of UNIX (., /bin and /usr/bin hardcoded in the
>>shell) and in its present form, it has existed since the 7th edition of
>>UNIX. Which means PATH searching was used on PDP-11 16-bit minicomputers
>>in the 1970s. It didn't cause performance problems back
>>then and will thus certainly don't cause any today.
>
> There are cases where it _does_ cause performance degradation, if one or
> more of the PATH elements refer to NFS filesystems, for example.

The internet RTT from Reading/ UK to Dallas/ Texas is about
0.12s. That's fast enough that there's no noticeable latency in
interactive shell sessions. I doubt that many real-world NFS
installations span ⅕ of the planet and hence, the latencies certainly
ought to be a lot lower.

I'm growing a bit allergic to NFS as universal example of deviant
behaviour --- that's a problem of NFS and not of code innocently and
unknowingly making use of it.

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Default PATH setting - reduce to something more sensible? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-01-14 11:14 +0100
  Re: Default PATH setting - reduce to something more sensible? cross@spitfire.i.gajendra.net (Dan Cross) - 2025-01-14 13:55 +0000
  Re: Default PATH setting - reduce to something more sensible? Rainer Weikusat <rweikusat@talktalk.net> - 2025-01-14 17:16 +0000
    Re: Default PATH setting - reduce to something more sensible? scott@slp53.sl.home (Scott Lurndal) - 2025-01-14 17:22 +0000
      Re: Default PATH setting - reduce to something more sensible? Kaz Kylheku <643-408-1753@kylheku.com> - 2025-01-14 17:59 +0000
      Re: Default PATH setting - reduce to something more sensible? Rainer Weikusat <rweikusat@talktalk.net> - 2025-01-14 19:23 +0000
        Re: Default PATH setting - reduce to something more sensible? scott@slp53.sl.home (Scott Lurndal) - 2025-01-14 22:17 +0000
          Re: Default PATH setting - reduce to something more sensible? cross@spitfire.i.gajendra.net (Dan Cross) - 2025-01-14 23:24 +0000
          Re: Default PATH setting - reduce to something more sensible? Rainer Weikusat <rweikusat@talktalk.net> - 2025-01-15 15:38 +0000
            Re: Default PATH setting - reduce to something more sensible? scott@slp53.sl.home (Scott Lurndal) - 2025-01-15 15:52 +0000
              Re: Default PATH setting - reduce to something more sensible? Rainer Weikusat <rweikusat@talktalk.net> - 2025-01-15 19:19 +0000
                Re: Default PATH setting - reduce to something more sensible? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-01-16 00:03 +0100
                Re: Default PATH setting - reduce to something more sensible? scott@slp53.sl.home (Scott Lurndal) - 2025-01-15 23:14 +0000
                Re: Default PATH setting - reduce to something more sensible? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-01-19 13:50 +0100
                Re: Default PATH setting - reduce to something more sensible? cross@spitfire.i.gajendra.net (Dan Cross) - 2025-01-15 23:26 +0000
                Re: Default PATH setting - reduce to something more sensible? Rainer Weikusat <rweikusat@talktalk.net> - 2025-01-16 11:51 +0000
                Re: Default PATH setting - reduce to something more sensible? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-01-19 14:10 +0100
                Re: Default PATH setting - reduce to something more sensible? Rainer Weikusat <rweikusat@talktalk.net> - 2025-01-19 20:36 +0000
                Re: Default PATH setting - reduce to something more sensible? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-01-19 15:55 -0800
                Re: Default PATH setting - reduce to something more sensible? antispam@fricas.org (Waldek Hebisch) - 2025-01-16 17:01 +0000
                Re: Default PATH setting - reduce to something more sensible? Rainer Weikusat <rweikusat@talktalk.net> - 2025-01-16 19:07 +0000

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