Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > gnu.bash.bug > #15997
| Path | csiph.com!goblin1!goblin.stu.neva.ru!usenet.stanford.edu!not-for-mail |
|---|---|
| From | Peng Yu <pengyu.ut@gmail.com> |
| Newsgroups | gnu.bash.bug |
| Subject | Performance bug of {1..1000000}? |
| Date | Sat, 7 Mar 2020 10:39:36 -0600 |
| Lines | 26 |
| Approved | bug-bash@gnu.org |
| Message-ID | <mailman.2243.1583599181.2412.bug-bash@gnu.org> (permalink) |
| References | <CABrM6wmte=vqL1a8aHwLidDzcaUx3=G+n3ZsOz0TweHVFeQLjg@mail.gmail.com> |
| NNTP-Posting-Host | lists.gnu.org |
| Mime-Version | 1.0 |
| Content-Type | text/plain; charset="UTF-8" |
| X-Trace | usenet.stanford.edu 1583599181 24017 209.51.188.17 (7 Mar 2020 16:39:41 GMT) |
| X-Complaints-To | action@cs.stanford.edu |
| To | bug-bash@gnu.org |
| Envelope-to | bug-bash@gnu.org |
| DKIM-Signature | v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=3H/v3zqzfWYc01OaUhaVKRsGmUJ0PWtixOl4X0Aii7o=; b=QI+BDKkvAVzeY8xndvuGoyajsS4v19zLdUti/GmLanmOLPl7YgMnqRMvl+b59JtKyW ama6UGRa/Sxn9CC6wvvCPQEg4Yw0QsVxGmwxK2jYXKpxrlZdC7kcq5Angno+ble35Lhg 4/vhxVwksNElqgXFuZFbexrp6HnU64AHYWBXeChLk3Es2z1CM5FJBuwzDmmKIeP4jHsP 5YFnLsErtL34tvUSoCwUkizpfKw4c94S+5xKZfCyt7HJL3LBkDicl921Cp7YYrJTaQVn SICg6CdZ9sPH9LIcodDd2x+txXYdUizQVv+5iKjKs7P75JU9sS1JebpaGKYkr8BJBEMk Y1sg== |
| X-Google-DKIM-Signature | v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=3H/v3zqzfWYc01OaUhaVKRsGmUJ0PWtixOl4X0Aii7o=; b=qEngpgERcECVjKTIXO1lO3I0VyPw3Dcu8n3hXBtLKTtgj+uDEtBLdY+I3VnWaOxooG +ODYavLKn3BYUEOzfaZVju/mvsCDBfRUp55iJqtnxHzenNZRkvDYCXoMXMWAsPXibxzp TcMzmo9rVP8toLsqC7TItclGBx+jisDLRyAix422LOI9I1IuSABoyHltTt6eMppbrDeB dXyt0IekJPDQdz9L99+U6RYW/TeYN/X42k0BLCcKGaf523hSsMJklZwbRHSteTCXSOAG WuG+hPQTt18yI5qtzLP9hBrdWw5BeyUD6Qggzu2mjNg7bt5HhcxhlxS9jQV3IEPGZdM3 EbkA== |
| X-Gm-Message-State | ANhLgQ0Caugaty7iEU7RaghQfpJxQkZsbWvhAmJoA3tRn+kew32hGFLg +1ybJEJlD9DS+1LCmz+mQLi3w722rG4csP4gplqfzA== |
| X-Google-Smtp-Source | ADFU+vs+MrG/4HtKn5KaF2SEhSab7SOx4/yKcghc8dxNMQLMYSXCOahLoPxZBrLgydSDsWPENkBxsb+VhSGZ9XKP/PU= |
| X-Received | by 2002:a02:6947:: with SMTP id e68mr8355248jac.137.1583599176608; Sat, 07 Mar 2020 08:39:36 -0800 (PST) |
| X-detected-operating-system | by eggs.gnu.org: Genre and OS details not recognized. |
| X-Received-From | 2607:f8b0:4864:20::d2a |
| X-BeenThere | bug-bash@gnu.org |
| X-Mailman-Version | 2.1.23 |
| Precedence | list |
| List-Id | Bug reports for the GNU Bourne Again SHell <bug-bash.gnu.org> |
| List-Unsubscribe | <https://lists.gnu.org/mailman/options/bug-bash>, <mailto:bug-bash-request@gnu.org?subject=unsubscribe> |
| List-Archive | <https://lists.gnu.org/archive/html/bug-bash> |
| List-Post | <mailto:bug-bash@gnu.org> |
| List-Help | <mailto:bug-bash-request@gnu.org?subject=help> |
| List-Subscribe | <https://lists.gnu.org/mailman/listinfo/bug-bash>, <mailto:bug-bash-request@gnu.org?subject=subscribe> |
| X-Mailman-Original-Message-ID | <CABrM6wmte=vqL1a8aHwLidDzcaUx3=G+n3ZsOz0TweHVFeQLjg@mail.gmail.com> |
| Xref | csiph.com gnu.bash.bug:15997 |
Show key headers only | View raw
See the following run time comparison. {1..1000000} is slower than
$(seq 1000000).
Since seq involves an external program, I'd expect the latter to be
slower. But the comparison shows the opposite.
I guess seq did some optimization?
Can the performance of {1..1000000} be improved so that it is faster
than $(seq 1000000)?
$ time builtin printf %.sx {1..1000000} > /dev/null
real 0m2.614s
user 0m2.361s
sys 0m0.166s
$ time builtin printf %.sx $(seq 1000000) > /dev/null
real 0m1.516s
user 0m1.317s
sys 0m0.158s
--
Regards,
Peng
Back to gnu.bash.bug | Previous | Next | Find similar
Performance bug of {1..1000000}? Peng Yu <pengyu.ut@gmail.com> - 2020-03-07 10:39 -0600
csiph-web