word & non-word boundries

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

I have a test file (text.txt) with following lines.

<String>
<This is the firstline>
<This is the secondline>
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What I want to do is to do a find the exact match & replace.

 open (FH,"text.txt");
 @lines=<FH>;
 
 @patterns = qw/<string> line secondline/;
 @replace = qw/'<REPLACED>' 'line_R' 'secondline_R'/;

 foreach $line (@lines){
    chomp $line;
    for ($i=0;$i<=2;$i++){
    if ($line =~ /\B$patterns[$i]\B/i){
       $line =~ s/$patterns[$i]/$replace[$i]/i;
       push @repd,$line;
    }
    }
 }

 foreach $line (@repd){
    print "$line\n";
 }
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My desired output.

'<REPLACED>' //<String>->'<REPLACED>' <This is the 'secondline_R'> // secondline->'secondline_R'
[download]
But what i am getting as output
With RegExp '/\B$patterns$i\B/i'

'<REPLACED>' //Match only non-word char boundary.

With RegExp "/\b$patterns$i\b/i"

<This is the 'secondline_R'> //failed to match non-word chars '<,>'.

Can anybody help fixing my REGEXP to exactly match word & non-word chars?
Thanks,

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Re: word & non-word boundries by almut (Canon) on Mar 03, 2010 at 11:27 UTC
Why don't you put the `\b` / `\B` in the patterns spec? `@patterns = qw/\B<string>\B \bline\b \bsecondline\b/; ... if ($line =~ /$patterns[$i]/i){ $line =~ s/$patterns[$i]/$replace[$i]/i;` [download]	[reply] [d/l] [select]