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From: Michael Parson <mparson@bl.org>
To: tuhs@minnie.tuhs.org
Subject: Re: [TUHS] sh: cmd | >file
Date: Fri, 03 Jan 2020 16:49:26 -0600	[thread overview]
Message-ID: <c6db37131fdeace7dee01920f53ff85e@bl.org> (raw)
In-Reply-To: <CANCZdfqcLttTBo9H+W5bFncoeBkAJ20FdNb-VLR3px5=00+BxA@mail.gmail.com>

On 2020-01-03 13:44, Warner Losh wrote:
> On Fri, Jan 3, 2020, 1:39 PM markus schnalke <meillo@marmaro.de> wrote:
> 
>> Hoi.
>> 
>> [2020-01-03 13:45] markus schnalke <meillo@marmaro.de>
>> >
>> > I'd be interested in any stories and information around this
>> > topic.
>> 
>> Especially I'd like to know since when and why ``>file'' is a
>> full command? Was it clever design or by accident?
> 
> 
> It's used to open files in shell scripts. Iirc, exec >foo 5>& and the
> like...

I've also used it to truncate files:

$ dd if=/dev/zero of=file count=10
10+0 records in
10+0 records out
5120 bytes (5.1 kB, 5.0 KiB) copied, 0.000686599 s, 7.5 MB/s

$ ls -l file
-rw-rw-r-- 1 mparson mparson 5120 Jan  3 16:45 file

$ >file

$ ls -l file
-rw-rw-r-- 1 mparson mparson 0 Jan  3 16:46 file

A more likely use case is to truncate a log file then HUP syslogd.

-- 
Michael Parson
Pflugerville, TX
KF5LGQ

  reply	other threads:[~2020-01-03 23:01 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-03 12:45 markus schnalke
2020-01-03 14:00 ` Steffen Nurpmeso
2020-01-03 17:03   ` Brian Zick
2020-01-03 17:18     ` markus schnalke
2020-01-04  0:53       ` Sven Mascheck via TUHS
2020-01-04 20:41         ` Steffen Nurpmeso
2020-01-03 19:38 ` markus schnalke
2020-01-03 19:44   ` Warner Losh
2020-01-03 22:49     ` Michael Parson [this message]
2020-01-03 23:32   ` Dave Horsfall
2020-01-04  2:58 Doug McIlroy
2020-01-04 10:07 ` markus schnalke
2020-01-04 11:47   ` Robert Clausecker
2020-01-04 22:31     ` Chet Ramey
2020-01-04 21:02   ` Dave Horsfall
2020-01-04 21:06     ` Jon Steinhart
2020-01-05  0:03       ` Eric Allman
2020-01-05  1:49         ` Adam Thornton
2020-01-05  2:44           ` Chet Ramey
2020-01-05  8:15             ` Brantley Coile
2020-01-05 15:16               ` Chet Ramey
2020-01-04 21:11     ` Dave Horsfall
2020-01-04 21:39       ` Warner Losh
2020-01-04 22:19         ` Terry Jones
2020-01-04 22:33           ` Chet Ramey
2020-01-04 23:53             ` Dave Horsfall
2020-01-05  0:04               ` Andreas Kusalananda Kähäri
2020-01-05  2:41               ` Chet Ramey
2020-01-05 13:45                 ` Sven Mascheck via TUHS
2020-01-05 15:18                   ` Chet Ramey
2020-01-05 21:21                 ` Dave Horsfall
2020-01-06 13:53                   ` Chet Ramey
2020-01-06 15:42                     ` Brantley Coile
2020-01-06 15:46                       ` arnold
2020-01-06 16:13                         ` Clem Cole
2020-01-06 20:44                           ` arnold
2020-01-06 20:51                             ` Steve Nickolas
2020-01-06 21:32                             ` Clem Cole
2020-01-06 21:39                               ` Brad Spencer
2020-01-06 21:29                         ` Dave Horsfall
2020-01-06 21:55                           ` Chet Ramey
2020-01-06 22:22                             ` Dave Horsfall
2020-01-06 22:52                             ` Dan Cross
2020-01-07  0:50                             ` Adam Thornton
2020-01-06 22:10                           ` Bakul Shah
2020-01-04 22:44           ` markus schnalke
2020-01-04 23:01             ` Terry Jones
2020-01-04 22:22         ` Dave Horsfall
2020-01-06  3:24 Brian Walden
2020-01-06 15:42 ` Richard Salz
2020-01-06 15:45   ` Brantley Coile
2020-01-06 16:11 Brian Walden
2020-01-06 16:33 ` Clem Cole
2020-01-06 19:47 Doug McIlroy
2020-01-07  4:49 Brian Walden
2020-01-07  5:03 Brian Walden

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