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Re: a sed question

From Salvador Mirzo <smirzo@example.com>
Newsgroups comp.unix.shell
Subject Re: a sed question
Date 2024-12-19 09:05 -0300
Organization A noiseless patient Spider
Message-ID <87wmfv27yy.fsf@example.com> (permalink)
References <874j304vv3.fsf@example.com> <lshab3Fk6t3U1@mid.individual.net>

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Ralf Damaschke <rwspam@gmx.de> writes:

> Salvador Mirzo wrote:
>
>> I failed the exercise I gave myself.  Can you help me to understand why
>> the q command isn't stopping sed as I thought it would?  I'd like to get
>> a better intuition.
>
> The specification in https://pubs.opengroup.org/onlinepubs/9799919799/

That's the home page.  I believe you meant to link the sed page
directly.  When copying URLs from the specification, we need to copy the
framed URL, otherwise we always end up at the home page.  The framed sed
page is at 

  https://pubs.opengroup.org/onlinepubs/9799919799/utilities/sed.html

> says at the end of the c command "Start the next cycle."
> So any commands following it won't be executed.
> The rationale does not mention the reason for the behavior specified.

Interesting.  Thanks for mentioning.  I wonder if I understand the
information.  I tried to change a line and then append another.  In both
FreeBSD's and GNU's sed, I the append takes place (and I thought they
would not if they were to obey the specification).

$ cat x.txt
a line
x
more lines
more lines

$ sed '/^x/{c\
hello
a\
hi
}' x.txt
a line
hello
hi
more lines
more lines
$

> Here, replacing the single-line c command with s/.*/$tag/ would do it.
> If you needed a range of lines to be changed, that might become tricky.

I don't need a range of lines to be changed, but I'd like to replace the
string only in the second line of the narrow region of interest.  I
tried your idea and it works, so I guess that way I can be POSIX-compliant.

-- 
Thanks!

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Thread

a sed question Salvador Mirzo <smirzo@example.com> - 2024-12-18 16:46 -0300
  Re: a sed question John-Paul Stewart <jpstewart@personalprojects.net> - 2024-12-18 15:12 -0500
  Re: a sed question Ralf Damaschke <rwspam@gmx.de> - 2024-12-19 01:14 +0000
    Re: a sed question Salvador Mirzo <smirzo@example.com> - 2024-12-19 09:05 -0300
      Re: a sed question Ralf Damaschke <rwspam@gmx.de> - 2024-12-20 00:55 +0000
        Re: a sed question gazelle@shell.xmission.com (Kenny McCormack) - 2024-12-20 12:44 +0000
          Re: a sed question Ralf Damaschke <rwspam@gmx.de> - 2024-12-21 00:17 +0000
            Re: a sed question Kaz Kylheku <643-408-1753@kylheku.com> - 2024-12-21 03:09 +0000
              sed... (Was: a sed question) gazelle@shell.xmission.com (Kenny McCormack) - 2024-12-21 03:36 +0000
                Re: sed... (Was: a sed question) Kaz Kylheku <643-408-1753@kylheku.com> - 2024-12-21 03:57 +0000
                Re: sed... (Was: a sed question) Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-21 15:38 +0100
                Re: sed... (Was: a sed question) Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-21 17:29 +0100
                Re: sed... Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-12-21 14:23 -0800
                Re: sed... Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-22 00:33 +0100
                Re: sed... (Was: a sed question) Lars Poulsen <lars@cleo.beagle-ears.com> - 2024-12-21 21:46 +0000
                Re: sed... (Was: a sed question) Kaz Kylheku <643-408-1753@kylheku.com> - 2024-12-22 21:22 +0000
              Re: a sed question Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-21 15:35 +0100
              Re: a sed question Ralf Damaschke <rwspam@gmx.de> - 2024-12-22 00:43 +0000
  Re: a sed question Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-20 15:55 +0100
    Checking for right # of args in a shell script (Was: a sed question) gazelle@shell.xmission.com (Kenny McCormack) - 2024-12-20 15:11 +0000
      Re: Checking for right # of args in a shell script (Was: a sed question) Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-20 16:49 +0100
        Re: Checking for right # of args in a shell script (Was: a sed question) gazelle@shell.xmission.com (Kenny McCormack) - 2024-12-20 17:43 +0000
    Re: a sed question Salvador Mirzo <smirzo@example.com> - 2024-12-21 09:17 -0300
      Re: a sed question Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-21 16:19 +0100
        Re: a sed question Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-12-21 13:41 -0800
          Re: a sed question Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-22 00:50 +0100
            Re: a sed question Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-12-21 16:26 -0800
              Re: a sed question Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-22 01:41 +0100
            Re: a sed question Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-12-22 00:31 +0000
              Re: a sed question Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-22 02:06 +0100
      Re: a sed question Andy Walker <anw@cuboid.co.uk> - 2024-12-21 15:34 +0000
        Re: a sed question Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-21 17:14 +0100
        Re: a sed question Salvador Mirzo <smirzo@example.com> - 2024-12-21 15:21 -0300
          Re: a sed question Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-21 20:48 +0100
      Re: a sed question Helmut Waitzmann <nn.throttle@xoxy.net> - 2024-12-21 19:20 +0100
    Re: a sed question Ordatious <order@order.invalid> - 2024-12-22 09:19 +0000
      Re: a sed question Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-22 19:23 +0100
  Re: a sed question Ed Morton <mortonspam@gmail.com> - 2024-12-21 08:13 -0600
    Re: a sed question Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-12-21 21:09 +0000
      Re: a sed question Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-22 01:02 +0100
        Re: a sed question Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-12-22 00:28 +0000
          Re: a sed question Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-12-21 16:36 -0800
            Re: a sed question Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-12-22 01:52 +0000
              Re: a sed question Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-12-21 21:09 -0800
                Re: a sed question Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-12-22 05:56 +0000
                Re: a sed question Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-12-21 22:55 -0800
                Re: a sed question Eric Pozharski <apple.universe@posteo.net> - 2024-12-23 10:09 +0000
                Re: a sed question gazelle@shell.xmission.com (Kenny McCormack) - 2024-12-23 12:41 +0000
                Re: a sed question Kaz Kylheku <643-408-1753@kylheku.com> - 2024-12-23 18:47 +0000
                Re: a sed question Eric Pozharski <apple.universe@posteo.net> - 2024-12-24 11:20 +0000
          Re: a sed question Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-22 02:22 +0100
      Re: a sed question gazelle@shell.xmission.com (Kenny McCormack) - 2024-12-22 01:09 +0000
      Re: a sed question Kaz Kylheku <643-408-1753@kylheku.com> - 2024-12-22 20:03 +0000
      Re: a sed question Ed Morton <mortonspam@gmail.com> - 2024-12-23 07:26 -0600
        How to solve The Miracle (was Re: a sed question) Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-12-23 21:09 +0100
        Re: a sed question Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-12-23 22:57 +0000
          Re: a sed question Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-12-23 15:06 -0800
            Re: a sed question Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-12-24 00:28 +0000
              Re: a sed question anthk <anthk@openbsd.home> - 2025-03-23 09:45 +0000
                Re: a sed question Lawrence D'Oliveiro <ldo@nz.invalid> - 2025-03-23 23:41 +0000
          Re: a sed question Ed Morton <mortonspam@gmail.com> - 2024-12-24 06:20 -0600
            Dealing with four-year-olds... (Was: a sed question) gazelle@shell.xmission.com (Kenny McCormack) - 2024-12-24 12:58 +0000
            Re: a sed question Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-12-24 20:57 +0000
              Re: a sed question Kaz Kylheku <643-408-1753@kylheku.com> - 2024-12-24 21:46 +0000
                Arguing with a four-year-old (Was: a sed question) gazelle@shell.xmission.com (Kenny McCormack) - 2024-12-24 23:53 +0000

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