Re: Useless use of shell pipelines [was: Useful use of dd]

From	l0f4r0@tuta.io
Newsgroups	linux.debian.user
Subject	Re: Useless use of shell pipelines [was: Useful use of dd]
Date	2021-07-03 10:30 +0200
Message-ID	<CwJcd-1q2-1@gated-at.bofh.it> (permalink)
References	(2 earlier) <Cwhzj-715-1@gated-at.bofh.it> <CwilH-7y5-1@gated-at.bofh.it> <CwkdP-rs-3@gated-at.bofh.it> <Cwm5X-1xu-5@gated-at.bofh.it> <Cwz3c-135-5@gated-at.bofh.it>
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Hi,

2 juil. 2021, 23:30 de dpchrist@holgerdanske.com:

> Perhaps the underlying issue is useless use of shell pipelines ("The Unix Way"):
>
> 2021-07-02 12:44:43 dpchrist@dipsy ~/sandbox/perl
> $ cat useless-use-of-grep
> This is the first line: bla bla bla.
> This is line xxxx: bla bla bla.
> This is the last line: bla bla bla.
>
> 2021-07-02 12:45:38 dpchrist@dipsy ~/sandbox/perl
> $ grep xxxx useless-use-of-grep | sed -e 's/bla/foo/'
> This is line xxxx: foo bla bla.
>
>
> Versus "all-in-one":
>
> 2021-07-02 12:45:39 dpchrist@dipsy ~/sandbox/perl
> $ perl -ne 's/bla/foo/ && print if /xxxx/' useless-use-of-grep
> This is line xxxx: foo bla bla.
>
>
> The former is better from a "golfing" standpoint (e.g. fewer characters to type).
>
Here is a better `sed` if you want a all-in-one: 
sed -n /xxxx/{s/bla/foo/p} useless-use-of-grep

> But, it is interesting that the benchmark results defy the common perceptions of "userland tools are are fast" and "Perl is slow":
>
> 2021-07-02 12:59:55 dpchrist@dipsy ~/sandbox/perl
> $ time for n in {1..10000}; do grep xxxx useless-use-of-grep | sed -e 's/bla/foo/' > /dev/null ; done
>
> real	0m42.162s
> user	0m32.925s
> sys	0m45.787s
>
> 2021-07-02 13:00:45 dpchrist@dipsy ~/sandbox/perl
> $ time for n in {1..10000}; do perl -ne 's/bla/foo/ && print if /xxxx/' useless-use-of-grep > /dev/null; done
>
> real	0m23.624s
> user	0m14.308s
> sys	0m10.826s
>
I'm not in front of my Linux terminal, can someone launch the `time` command for my `sed` above please ? :)

Best regards, 
l0f4r0

Thread

Whole Disk Encryption + SSD piorunz <piorunz@gmx.com> - 2021-06-28 17:00 +0200
  Re: Whole Disk Encryption + SSD Jochen Spieker <ml@well-adjusted.de> - 2021-06-28 18:00 +0200
  Re: Whole Disk Encryption + SSD David Christensen <dpchrist@holgerdanske.com> - 2021-06-28 22:40 +0200
    Re: Whole Disk Encryption + SSD David Christensen <dpchrist@holgerdanske.com> - 2021-06-29 00:00 +0200
    Re: Whole Disk Encryption + SSD Stefan Monnier <monnier@iro.umontreal.ca> - 2021-06-29 02:00 +0200
      Re: Whole Disk Encryption + SSD <tomas@tuxteam.de> - 2021-06-29 09:50 +0200
        Re: Whole Disk Encryption + SSD Stefan Monnier <monnier@iro.umontreal.ca> - 2021-06-30 00:50 +0200
        Re: Whole Disk Encryption + SSD David Christensen <dpchrist@holgerdanske.com> - 2021-06-30 01:00 +0200
    Re: Whole Disk Encryption + SSD Jonathan Dowland <jon+debian-user@dow.land> - 2021-06-29 11:30 +0200
    Re: Whole Disk Encryption + SSD piorunz <piorunz@gmx.com> - 2021-06-29 14:10 +0200
      Re: Whole Disk Encryption + SSD David Christensen <dpchrist@holgerdanske.com> - 2021-06-30 02:20 +0200
    Re: Whole Disk Encryption + SSD David Wright <deblis@lionunicorn.co.uk> - 2021-07-02 05:00 +0200
      Re: Whole Disk Encryption + SSD David Christensen <dpchrist@holgerdanske.com> - 2021-07-02 05:50 +0200
        Useless use of "dd" Teemu Likonen <tlikonen@iki.fi> - 2021-07-02 07:50 +0200
          Useful use of dd [was: Useless use of "dd"] <tomas@tuxteam.de> - 2021-07-02 09:50 +0200
            Re: Useful use of dd [was: Useless use of "dd"] Teemu Likonen <tlikonen@iki.fi> - 2021-07-02 12:30 +0200
              Re: Useful use of dd "Thomas Schmitt" <scdbackup@gmx.net> - 2021-07-02 13:00 +0200
                Re: Useful use of dd <tomas@tuxteam.de> - 2021-07-02 13:20 +0200
                Re: Useful use of dd Teemu Likonen <tlikonen@iki.fi> - 2021-07-02 13:30 +0200
                Re: Useful use of dd David Christensen <dpchrist@holgerdanske.com> - 2021-07-02 23:50 +0200
              Re: Useful use of dd [was: Useless use of "dd"] <tomas@tuxteam.de> - 2021-07-02 13:20 +0200
              Re: Useful use of dd Michael Stone <mstone@debian.org> - 2021-07-02 14:50 +0200
              Re: Useful use of dd [was: Useless use of "dd"] Kushal Kumaran <kushal@locationd.net> - 2021-07-02 21:10 +0200
                Creation of empty files [was: Useful use of dd] David Christensen <dpchrist@holgerdanske.com> - 2021-07-02 23:40 +0200
                Re: Creation of empty files [was: Useful use of dd] David Christensen <dpchrist@holgerdanske.com> - 2021-07-03 00:00 +0200
                Re: Creation of empty files [was: Useful use of dd] Michael Stone <mstone@debian.org> - 2021-07-03 15:50 +0200
                Re: Creation of empty files [was: Useful use of dd] David Christensen <dpchrist@holgerdanske.com> - 2021-07-03 23:40 +0200
                Re: Creation of empty files [was: Useful use of dd] Michael Stone <mstone@debian.org> - 2021-07-04 06:00 +0200
            Re: Useful use of dd [was: Useless use of "dd"] Greg Wooledge <greg@wooledge.org> - 2021-07-02 13:40 +0200
              Re: Useful use of dd [was: Useless use of "dd"] <tomas@tuxteam.de> - 2021-07-02 13:40 +0200
                Re: Useful use of dd [was: Useless use of "dd"] David Wright <deblis@lionunicorn.co.uk> - 2021-07-02 17:10 +0200
                Re: Useful use of dd [was: Useless use of "dd"] <tomas@tuxteam.de> - 2021-07-02 17:40 +0200
                Re: Useful use of dd [was: Useless use of "dd"] Gunnar Gervin <dofeelok@gmail.com> - 2021-07-03 09:20 +0200
                Re: Useful use of dd [was: Useless use of "dd"] <tomas@tuxteam.de> - 2021-07-03 09:30 +0200
            Useless use of shell pipelines [was: Useful use of dd] David Christensen <dpchrist@holgerdanske.com> - 2021-07-02 23:40 +0200
              Re: Useless use of shell pipelines [was: Useful use of dd] l0f4r0@tuta.io - 2021-07-03 10:30 +0200
                Re: Useless use of shell pipelines [was: Useful use of dd] Greg Wooledge <greg@wooledge.org> - 2021-07-03 15:40 +0200
          Re: Useless use of "dd" David Christensen <dpchrist@holgerdanske.com> - 2021-07-02 21:40 +0200
        Re: Whole Disk Encryption + SSD David Wright <deblis@lionunicorn.co.uk> - 2021-07-02 17:10 +0200
          Re: Whole Disk Encryption + SSD Michael Stone <mstone@debian.org> - 2021-07-02 17:30 +0200
          Re: Whole Disk Encryption + SSD David Christensen <dpchrist@holgerdanske.com> - 2021-07-02 20:40 +0200

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