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•Update: I've retracted this post, it doesn't apply to the situation (I missed the part about it being db records that need to be updated) This stuff below is only useful if you need to do the substitutions in a string.

use strict; use warnings; my %replace = qw( COM SEC MOC COM SEC COM CO MOC ); my $searchpat = join '|', sort { length $b <=> length $a } keys %repla +ce; $searchpat = qr/$searchpat/; # optional, dunno if it speeds up things my $example = "FOO CO COM BAR MOC SEC"; $example =~ s/($searchpat)/$replace{$1}/g; print "$example\n";
Produces the output:
FOO MOC SEC BAR COM COM
As you can see, it also handles circularity without problem; COM <-> SEC.

Note that I'm sorting the keys on length to make sure longer patterns match first (otherwise "COM" would become "SECM").


If the search-string needs to occur as a word by itself, use \b, like:
my $example = "MOC.COMPUTER.COM.FOO / SEC.SECT / CO"; $example =~ s/\b($searchpat)\b/$replace{$1}/g; print "$example\n";
which prints:
COM.COMPUTER.SEC.FOO / COM.SECT / MOC

Note that in this case sorting on the length of the key is not necessary, so you can simply do my $searchpat = join '|', keys %replace;


Final note: this code assumes the keys don't contain any odd chars like regex metachars. Since your example shows all-uppercase abbreviations, so apparently this isn't a problem. If it is, then you'll need to look into using quotemeta.

 

In reply to Re: Ordering hash replacements to avoid clobbering things by xmath
in thread Ordering hash replacements to avoid clobbering things (update chaining) by grinder

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