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Re: Escaping of line breaks for text replacement

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Markus Elfring <Markus.Elfring@web.de> wrote:
>>> I wonder why I do not get this approach to work so far with some
>>> additional backslashes here. How should newlines be escaped for
>>> this purpose?
>> 
>> Use the shell's backslash-escape expansion ($'what\never').
> 
> Is the shell pattern substitution alone really insufficient for the
> requested use case?

XY='one
two
three
four'

If you don't mind using embedded newlines in the substitution:

Z=${XY//'
'/'\
'}

Or

nl='
'

Z=${XY//"$nl"/"\\$nl"}

> 
> 
>> It's not just newlines, any characters in the replacement text which
>> match sed's s command delimiter
> 
> Thanks for your reminder.

See Kaz' post for a correction to that -- there are other characters
(and sequences) which would cause errors if they appear in the replacement
text.

  $ foo="&&"
  $ echo "error" | sed "s,r,$foo,g"
  errrrorr
  $ foo='\1'
  $ echo "error" | sed "s,r,$foo,g"
  sed: -e expression #1, char 8: invalid reference \1 on `s' command's RHS

> 
>> ('/' by default)
> 
> Would you like to indicate here that this special character can
> eventually be adjusted by a parameter or environment variable?

sed accepts any character as delimiter for the substitution command
making it possible to use any character which is known not to appear
in the replacement text.

Here with a comma:

  sed "s,something,${XY},g"

If you need it to be adjustable:

  sep=:
  sed "s${sep}something${sep}${XY}${sep}g"

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Thread

Escaping of line breaks for text replacement Markus Elfring <Markus.Elfring@web.de> - 2014-03-02 14:00 +0100
  Re: Escaping of line breaks for text replacement jt@toerring.de (Jens Thoms Toerring) - 2014-03-02 15:49 +0000
    Re: Escaping of line breaks for text replacement Markus Elfring <Markus.Elfring@web.de> - 2014-03-03 08:38 +0100
  Re: Escaping of line breaks for text replacement dave.gma+news002@googlemail.com.invalid (Dave Sines) - 2014-03-02 16:52 +0000
    Re: Escaping of line breaks for text replacement Kaz Kylheku <kaz@kylheku.com> - 2014-03-02 17:53 +0000
      Re: Escaping of line breaks for text replacement Kaz Kylheku <kaz@kylheku.com> - 2014-03-02 20:27 +0000
        Re: Escaping of line breaks for text replacement dave.gma+news002@googlemail.com.invalid (Dave Sines) - 2014-03-03 16:17 +0000
          Re: Escaping of line breaks for text replacement Kaz Kylheku <kaz@kylheku.com> - 2014-03-03 17:44 +0000
            Re: Escaping of line breaks for text replacement Geoff Clare <geoff@clare.See-My-Signature.invalid> - 2014-03-04 13:30 +0000
    Re: Escaping of line breaks for text replacement Markus Elfring <Markus.Elfring@web.de> - 2014-03-02 20:50 +0100
      Re: Escaping of line breaks for text replacement dave.gma+news002@googlemail.com.invalid (Dave Sines) - 2014-03-03 16:52 +0000
    Re: Escaping of line breaks for text replacement Markus Elfring <Markus.Elfring@web.de> - 2014-03-03 09:24 +0100
    Re: Escaping of line breaks for text replacement Markus Elfring <Markus.Elfring@web.de> - 2014-03-03 12:55 +0100
      Re: Escaping of line breaks for text replacement dave.gma+news002@googlemail.com.invalid (Dave Sines) - 2014-03-03 17:02 +0000
        Re: Escaping of line breaks for text replacement Markus Elfring <Markus.Elfring@web.de> - 2014-03-06 12:02 +0100
          Re: Escaping of line breaks for text replacement dave.gma+news002@googlemail.com.invalid (Dave Sines) - 2014-03-06 18:51 +0000
            Re: Escaping of line breaks for text replacement Markus Elfring <Markus.Elfring@web.de> - 2014-03-06 20:48 +0100
              Re: Escaping of line breaks for text replacement dave.gma+news002@googlemail.com.invalid (Dave Sines) - 2014-03-06 22:59 +0000
                Re: Escaping of line breaks for text replacement Kaz Kylheku <kaz@kylheku.com> - 2014-03-07 06:38 +0000
                Re: Escaping of line breaks for text replacement Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-03-07 13:33 +0000
                Re: Escaping of line breaks for text replacement dave.gma+news002@googlemail.com.invalid (Dave Sines) - 2014-03-07 15:08 +0000
                Re: Escaping of line breaks for text replacement Markus Elfring <Markus.Elfring@web.de> - 2014-03-07 11:23 +0100
                Re: Escaping of line breaks for text replacement dave.gma+news002@googlemail.com.invalid (Dave Sines) - 2014-03-07 14:43 +0000
                Re: Escaping of line breaks for text replacement Markus Elfring <Markus.Elfring@web.de> - 2014-03-07 17:23 +0100
                Re: Escaping of line breaks for text replacement dave.gma+news002@googlemail.com.invalid (Dave Sines) - 2014-03-07 19:53 +0000
                Bash 4.3.0 escape expansion (was: Re: Escaping of line breaks for text replacement) dave.gma+news002@googlemail.com.invalid (Dave Sines) - 2014-03-08 12:26 +0000
                Re: Bash 4.3.0 escape expansion (was: Re: Escaping of line breaks for text replacement) Kaz Kylheku <kaz@kylheku.com> - 2014-03-08 20:05 +0000
                Re: Bash 4.3.0 escape expansion Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-03-09 03:48 +0000
                Re: Bash 4.3.0 escape expansion dave.gma+news002@googlemail.com.invalid (Dave Sines) - 2014-03-09 13:21 +0000
  Re: Escaping of line breaks for text replacement Kaz Kylheku <kaz@kylheku.com> - 2014-03-02 18:11 +0000
    Re: Escaping of line breaks for text replacement Markus Elfring <Markus.Elfring@web.de> - 2014-03-02 20:08 +0100
      Re: Escaping of line breaks for text replacement Kaz Kylheku <kaz@kylheku.com> - 2014-03-02 20:35 +0000
        Re: Which content should be escaped? Markus Elfring <Markus.Elfring@web.de> - 2014-03-03 10:30 +0100
          Re: Which content should be escaped? dave.gma+news002@googlemail.com.invalid (Dave Sines) - 2014-03-04 14:04 +0000
            Re: Which content should be escaped? Kaz Kylheku <kaz@kylheku.com> - 2014-03-04 17:32 +0000
  Re: Escaping of line breaks for text replacement Siri Cruz <chine.bleu@yahoo.com> - 2014-03-07 02:47 -0800

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