Re: regex/substitution question

Using that approach, you'll also have problems with

my %subs = (
   foo => 'bar',
   bar => 'baz',
);
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"foo" my end up being substituted with "baz".

You want to search for all regex in the same pass

s/(foo|bar)/$subs{$1}/g
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And you want to search for the longest matches first.

s/(Xaa11|Xaa1)/$subs{$1}/g
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So what you want is

my $pat = join '|', map quotemeta, sort { length($b) <=> length($a) } 
+keys(%subs);
s/($pat)/$subs{$1}/g;
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Alternatively, if you're always matching entire words, you could forgo the sorting in favour of using anchors.

my $pat = join '|', map quotemeta, keys(%subs);
s/\b($pat)\b/$subs{$1}/g;
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Re^2: regex/substitution question by slugger415 (Monk) on Feb 07, 2012 at 19:32 UTC
Excellent! Thank you. I've not used "map" before so will have to study that one. Regarding the use of \b, I'm wondering if my hash name contains a period at the end, what would happen? This seems to work fine but am I causing a potential problem? I guess my question is, since . is also a word boundary, might it leave it in in the substitution? `%subs = ("Xaa1." => "sub1"); foreach $s (keys %subs){ $data =~ s/\b$e\b[.]?/$subs{$s}/g; }` [download] Anyway thanks much, this is very helpful. UPDATE: Ignore that last question. What I meant was, if $data contains a period after Xaa1, not the name in %subs. `Here is my Xaa1. data string.` But I think I'm asking a confusing question.. so please ignore. :-)	[reply] [d/l] [select]
Re^3: regex/substitution question by ikegami (Patriarch) on Feb 07, 2012 at 21:43 UTC
I'm wondering if my hash name contains a period at the end, what would happen? Depends on what you expect to follow the period, but I'm betting it wouldn't be appropriate to use \b.	[reply]