in reply to hex code passed from command line is interpreted literally in substitution

Add /e to the substitution: 

$var =~ s@$arg_1@$arg_2@e;

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Re^2: hex code passed from command line is interpreted literally in substitution
by Allasso (Monk) on Mar 05, 2011 at 21:17 UTC

    "Add /e to the substitution:"

    that didn't work for me.

[reply]

      Then I guess I misunderstand what you are trying to do: 

      $find = "\x20"; $rep = "\x30";;

$s = "The quick brown fox jumps over the lazy dog";;

$s =~ s[$find][$rep]eg;;

print $s;;
The0quick0brown0fox0jumps0over0the0lazy0dog

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      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
[d/l]
        I am trying to pass those expressions from the command line. It works fine the way you have your code written, but try this: 
        
my ($find, $rep) = @ARGV;

$s = "The quick brown fox jumps over the lazy dog";;

$s =~ s[$find][$rep]eg;;


./arg.pl '\x20' '\x30'

#prints:

The\x30quick\x30brown\x30fox\x30jumps\x30over\x30the\x30lazy\x30dog

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[reply]
[d/l]

        The /e option on your s/// makes no difference there for two reasons.

        First, you aren't testing what was asked about. $rep = "\x30"; is identical to $rep = "0";. "0" evaluates to "0" so /e makes no difference.

        Second, s/.../$rep/ (no /e) does string interpolation on the $rep part which results in the value from $rep being used. s/.../$rep/e (with /e) interpolates $rep as Perl code and the value of eval '$rep' is also just the value stored in $rep.

        - tye        

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