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Re^2: Windows and backslashes and replacements oh my!

by stevieb (Canon)
on Jun 18, 2021 at 18:57 UTC ( [id://11134016]=note: print w/replies, xml ) Need Help??


in reply to Re: Windows and backslashes and replacements oh my!
in thread Windows and backslashes and replacements oh my!

Changing the line to the following has resolved the issue:

call perl -i.bak -ne "my $bs=chr(92); s/berrybrew(?!\\+test)/berrybrew +${bs}${bs}test/; print" test/data/config.json

Thanks!

Replies are listed 'Best First'.
Re^3: Windows and backslashes and replacements oh my!
by LanX (Saint) on Jun 18, 2021 at 19:28 UTC
Re^3: Windows and backslashes and replacements oh my!
by The Perlman (Scribe) on Jun 19, 2021 at 09:34 UTC
    ${bs}${bs} means using two consecutive backslashes, which is still weird.

    Looks like somewhere a Unix tool like bash or another Perl is processing the file.

    (Update: Obviously Perl needs to escape the backslash inside a regex)

    FWIW: using $b2=chr(92)x2 might save you some typing

    - Ron
      One $bs is sufficient in my tests:

      d:\>perl -E"for $x (qw/C:\berrybrew\test C:\berrybrew /) {$_=$x; $bs=c +hr(92); s/berrybrew(?!\\+test)/berrybrew${bs}test/; say}" C:\berrybrew\test C:\berrybrew\test d:\>

      > Obviously Perl needs to escape the backslash inside a regex

      not after interpolation of variables like $bs

      Cheers Rolf
      (addicted to the Perl Programming Language :)
      Wikisyntax for the Monastery

        > > Obviously Perl needs to escape the backslash inside a regex

        > not after interpolation of variables like $bs

        I have to correct myself, it depends on the side of the substitution

        • the right side is a simple doublequoted string, so after interpolation no escaping
        • but the left side is a regex with two levels of escaping
          1. string interpolation with escaping first, i.e. \$bs won't be interpolated
          2. regex interpretation with escaping first, i.e. /\*/ is not a quantifier but literal * same with /$bs*/
        compare
        d:\>perl -E"for $x (qw/C:\berrybrew\test C:\berrybrew /) {$_=$x; $bs=c +hr(92); s#$bs$bs#<${bs}>#g; say}" C:<\>berrybrew<\>test C:<\>berrybrew d:\>

        or to eliminate the Win command line

        use v5.12; use warnings; use Data::Dump; my $bs=chr(92); for my $x (qw/C:\berrybrew\test C:\berrybrew /) { $_=$x; s#$bs$bs#<${bs}>#g; say; #ddx $_; } $_='$bs'; s/\$bs/<$&>/; say;
        C:<\>berrybrew<\>test C:<\>berrybrew <$bs>
        so this might be the OPs original problem

        see also

        s/RegEx/substitutions/: Variable interpolation and when to use /e - modifiers

        Cheers Rolf
        (addicted to the Perl Programming Language :)
        Wikisyntax for the Monastery

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