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Groups > linux.debian.user > #236802
| From | Greg Wooledge <greg@wooledge.org> |
|---|---|
| Newsgroups | linux.debian.user |
| Subject | Re: Useless use of shell pipelines [was: Useful use of dd] |
| Date | 2021-07-03 15:40 +0200 |
| Message-ID | <CwO2d-4tb-3@gated-at.bofh.it> (permalink) |
| References | (3 earlier) <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> <CwJcd-1q2-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Sat, Jul 03, 2021 at 10:23:39AM +0200, l0f4r0@tuta.io wrote:
> 2 juil. 2021, 23:30 de dpchrist@holgerdanske.com:
> > $ 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.
> Here is a better `sed` if you want a all-in-one:
> sed -n /xxxx/{s/bla/foo/p} useless-use-of-grep
Also:
awk '/xxxx/{sub("bla", "foo"); print}' useless-use-of-grep
> > $ 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 ? :)
unicorn:~$ time for n in {1..10000}; do perl -ne 's/bla/foo/ && print if /xxxx/' useless-use-of-grep; done >/dev/null
real 16.034 user 11.555 sys 4.847
unicorn:~$ time for n in {1..10000}; do sed -n '/xxxx/{s/bla/foo/p}' useless-use-of-grep; done >/dev/null
real 11.489 user 8.670 sys 3.251
unicorn:~$ time for n in {1..10000}; do awk '/xxxx/{sub("bla", "foo"); print}' useless-use-of-grep; done >/dev/null
real 15.690 user 11.575 sys 4.532
Sed wins this particular race, not surprisingly.
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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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