substitution problem with ()

sroy5 has asked for the wisdom of the Perl Monks concerning the following question:

Hi,
The prob is as follows:

$_ = "Child(x,y)";
$To = "Child(x,z)";
I need to substitute the above as
s/$_/$To/
print $_;
[download]

The Outcome should be as Child(x,z).
Note: the $_ data x,y and z are variable numeric depends on the numeric data it gets at run time.

Comment on substitution problem with () Download Code

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Re: substitution problem with () by ikegami (Patriarch) on Jun 12, 2007 at 16:39 UTC
The first argument of the substitution operator (`s///`) is a regexp, not arbitrary text. An easy way to convert arbitrary text into a regular expressions in to use `quotemeta`. `my $from_re = quotemeta($_); s/$from_re/$to/;` [download]	[reply] [d/l] [select]
Re^2: substitution problem with () by bart (Canon) on Jun 12, 2007 at 17:01 UTC
Or, in one go (and IMO simpler): `s/\Q$from_re/$to/;` [download] `"\Q$string"` is the same as `quotemeta($string)`, both in a doublequotish string and in a regexp.	[reply] [d/l] [select]
Re: substitution problem with () by shmem (Chancellor) on Jun 12, 2007 at 17:01 UTC
Note: the $_ data x,y and z are variable numeric depends on the numeric data it gets at run time. Unclear spec. In you code `z` isn't contained in `$_`. Where does it come from? I know what I mean. Why don't you? Read perlretut and perlre, that should get you on the way. --shmem _($_=" "x(1<<5)."?\n".q·/)Oo. G°\ / /\_¯/(q / ---------------------------- \__(m.====·.(_("always off the crowd"))."· ");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}	[reply] [d/l] [select]
Re: substitution problem with () by thezip (Vicar) on Jun 12, 2007 at 16:46 UTC
sroy5, could you please provide a few real-world examples of the transformation you seek? There's really not enough context here to see what you're trying to do. Where do you want them* to go today?*	[reply]


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