fouinix has asked for the wisdom of the Perl Monks concerning the following question:

Hi all; I simply want to do a search/replace of an ip adresse like this : 
my $ip_wan = new NetAddr::IP("10.20.20.1/24");
for (@line) {

s/<IP_WAN>/$ip_wan->addr()/;
}

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Perl replace "<IP_WAN>" by "10.20.20.1/24->addr()" and not "10.20.20.1". It seems perl ignore arrow operator "->" I tried with simple quote ' ' or double quote " " No success :(

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Re: Perl ignore arrow object operator in search/replace
by pajout (Curate) on Feb 17, 2014 at 12:19 UTC
    But specially for your example, you can do it like
    my $ip_wan = new NetAddr::IP("10.20.20.1/24");
my $ip_addr = $ip_wan->addr();

for (@line) {
  s/<IP_WAN>/$ip_addr/;
}

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      Thanks :)
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Re: Perl ignore arrow object operator in search/replace (s/searchregex/replacestring/)
by Anonymous Monk on Feb 17, 2014 at 12:10 UTC
    There are no arrow operators in strings, the right hand side of the s///ubstitution operator  s{regex}{right} is a string, unless you use the /e modifier to signal that its code; so use s///e for code (one e is code, two ee is eval, three eee is eval eval --- insane )
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      > There are no arrow operators in strings,

      That's wrong! Variable interpolation does easily dereference hashes and arrays (i.e. within strings and substitutes). 

        DB<114> $h={a=>42}
 => { a => 42 }

  DB<115> "$h->{a}"
 => 42

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      Though coderefs seem to be excluded. 

        DB<118> $sub=sub { "nope" }
 => sub { "???" }

  DB<119> "$sub->()"
 => "CODE(0xa5cc200)->()"

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      But the @{[...]} ("local eval") trick always helps where a general /e would cause too much harm.

        DB<120> $_="X"
 => "X"

  DB<121> s/X/@{[ $sub->() ]}/
 => 1

  DB<122> $_
 => "nope"

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

      Cheers Rolf

      ( addicted to the Perl Programming Language)

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        The arrow operator works in strings for dereferencing hash and array elements, but not for calling coderefs, and not for method calls.

        As well as the "@{[ ... ]}" trick, another option is "${\ ... }".

        use Moops; class Cow :rw { has name => (default => 'Ermintrude') }; say Cow->new->name
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