Re: Word boundary '\B'

Neither ' ', '&', nor ';' are word characters, so there is no word boundary between them.

On the other hand, 'a', and 'f' are word characters (and '&' and ';' still aren't), so there are your word boundaries.

You probably want either negative or positive lookahead/lookbehind for (non-)whitespace instead. Negative version:

$str = 'abac &#x0007E;&#x0007E;&#x0007E; afa&#x0007E;&#x0007E;&#x0007E
+;f';
$str =~ s|(?<!\s)\&\#x0007E\;\&\#x0007E\;\&\#x0007E\;(?!\s)|~~~|g;
print $str;
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Positive lookahead/lookbehind won't match at end/beginning of string:

$str = 'abac &#x0007E;&#x0007E;&#x0007E; afa&#x0007E;&#x0007E;&#x0007E
+;f';
$str =~ s|(?<=\S)\&\#x0007E\;\&\#x0007E\;\&\#x0007E\;(?=\S)|~~~|g;
print $str;
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print "Just another Perl ${\(trickster and hacker)},"
The Sidhekin proves Sidhe did it!

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Re^2: Word boundary '\B' - Question by prasadbabu (Prior) on Aug 21, 2006 at 15:46 UTC
Sidhekin, thanks for the clarification. I was deceived by the follwing line from the Perl in 21 days book. /\Bdef\B/ matches cdefg or abcdefghi, but not def, defghi, or abcdef. But now when i re-read the documentation i get clear answer. From Documentation: A word boundary (\b ) is a spot between two characters that has a \w on one side of it and a \W on the other side of it (in either order) Prasad	[reply]

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Re^2: Word boundary '\B' - Question
by prasadbabu (Prior) on Aug 21, 2006 at 15:46 UTC

Sidhekin, thanks for the clarification.

I was deceived by the follwing line from the Perl in 21 days book.

/\Bdef\B/ matches cdefg or abcdefghi, but not def, defghi, or abcdef.

But now when i re-read the documentation i get clear answer.

From Documentation:

A word boundary (\b ) is a spot between two characters that has a \w on one side of it and a \W on the other side of it (in either order)

Prasad

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