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From: Roman Perepelitsa <roman.perepelitsa@gmail.com>
To: zeurkous@blaatscaahp.org
Cc: dominik.vogt@gmx.de, Zsh Users <zsh-users@zsh.org>
Subject: Re: Re: time command with shell builtins
Date: Mon, 23 Jan 2023 15:23:57 +0100	[thread overview]
Message-ID: <CAN=4vMpZAa3cRqoWfLi8=J=Jt0N5_6egwgRAeRjOF5yFamnmyA@mail.gmail.com> (raw)
In-Reply-To: <thinkcrap!zeurkous!1674483444.13585@uucp>

On Mon, Jan 23, 2023 at 3:20 PM <zeurkous@blaatscaahp.org> wrote:
>
> On Mon, 23 Jan 2023 14:42:05 +0100, Roman Perepelitsa <roman.perepelitsa@gmail.com> wrote:
> > On Mon, Jan 23, 2023 at 2:40 PM Dominik Vogt <dominik.vogt@gmx.de> wrote:
> >>
> >> Is it possible to get timing statistics of shell builtins too?
> >> Timing "echo" isn't very interesting, but timing loop constructs
> >> would be:
> >>
> >>   $ time while foo; do bar done
> >
> > This:
> >
> >     % time ( while foo; do bar; done )
>
> Doesn't that imply a fork, which will also be timed...?

Yes, it does.

> (Could lead to misleading results, in that case.)

Any tool that measures how long a piece of code takes to run gives you
an upper bound, so there is nothing new here. The standard solution is
to ensure that the code under benchmark takes a non-trivial amount of
time to execute. Here's the standard pattern I use:

    time ( repeat 1000 code-under-benchmark )

I tune the loop constant so that the benchmark takes around a second.

Roman.


  reply	other threads:[~2023-01-23 14:24 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-23 13:40 Dominik Vogt
2023-01-23 13:42 ` Roman Perepelitsa
2023-01-23 14:17   ` zeurkous
2023-01-23 14:23     ` Roman Perepelitsa [this message]
2023-01-23 14:40       ` zeurkous
2023-01-23 14:28   ` Dominik Vogt
2023-01-23 14:46     ` zeurkous
2023-01-23 16:31     ` Bart Schaefer
2023-01-23 18:31     ` Mikael Magnusson
2023-01-23 18:49       ` Dominik Vogt
2023-01-24  9:32         ` Mikael Magnusson
2023-01-24 10:48           ` Dominik Vogt
2023-01-24 23:12             ` Dominik Vogt
2023-01-24 23:36               ` Bart Schaefer
     [not found]                 ` <Y9B7A8dWLiZNXKfW@localhost>
2023-01-26 16:23                   ` Dominik Vogt
2023-01-26 16:56                     ` Bart Schaefer
2023-01-26 17:26                       ` Dominik Vogt
2023-01-26 17:40                         ` Bart Schaefer
2023-02-02 18:10                     ` Dominik Vogt
2023-02-02 18:28                       ` Bart Schaefer
2023-02-02 19:15                         ` Dominik Vogt
2023-02-02 19:15                           ` Dominik Vogt
2023-02-02 19:31                           ` Bart Schaefer
2023-01-24 23:32             ` Bart Schaefer
2023-01-25  7:43               ` Mikael Magnusson
2023-01-25 12:58                 ` Dominik Vogt

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