Hi monks, Update: I have decided to use HTML::Parser to get this work done!!! Please look here Using XML::Twig| HTML::Parser to help me with my other queries. I have to write a program to extract characters from a text file. The text file looks like this 
dd class="xref">GeneID:947412</dd>
                        
                    
                    <dd class="xref">GenomeReviews:AP009048_GR</dd>
                        
                    
                    <dd class="xref">GenomeReviews:U00096_GR</dd>
                        
                    
                    <dd class="xref"><a href="http://amigo.geneontolog
+y.org/cgi-bin/amigo/term-details.cgi?term=GO:0005524">GO:0005524</a><
+/dd>
                        
                    
                    <dd class="xref"><a href="http://amigo.geneontolog
+y.org/cgi-bin/amigo/term-details.cgi?term=GO:0005886">GO:0005886</a><
+/dd>
                        
                    
                    <dd class="xref"><a href="http://amigo.geneontolog
+y.org/cgi-bin/amigo/term-details.cgi?term=GO:0006810">GO:0006810</a><
+/dd>
                        
                    
                    <dd class="xref"><a href="http://amigo.geneontolog
+y.org/cgi-bin/amigo/term-details.cgi?term=GO:0016301">GO:0016301</a><
+/dd>
                        
                    
                    <dd class="xref">HOGENOM:P27254</dd>

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I want to write a regular expression to extract "GO:(followed by those numbers)" only from this text and also it has to be extracted only once. This extracted string has to be stored in an array so I can pass it to another search query. I tried with this code $line1 =~ m/"^\s+(.+)(GO:)(\d+).+"/g; and it is not working. Can anyone help me out??

In reply to Help regarding regular expression by chavanak

Title:
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