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copied!<p>Since this is code review, let's go one by one:</p> <pre><code>#!/use/bin/perl </code></pre> <p>That shebang line is most likely a typo. It should probably be</p> <pre><code>#!/usr/bin/perl </code></pre> <p>or whatever <code>which perl</code> returns on your system.</p> <pre><code>use strict; use warnings; </code></pre> <p>Good.</p> <pre><code>open (FILE, "/home/user/Desktop/infile.phy") || die "cant open file\n"; </code></pre> <p>No need for package global filehandles when you can use lexical filehandles. The 3-argument form of <code>open</code> is preferable these days. Also, the error message should indicate the file which you could not open:</p> <pre><code>my $filename = '/home/user/Desktop/infile.phy'; open my $input, '<', $filename or die "Cannot open '$filename' for reading: $!"; my @body = <FILE>; </code></pre> <p>You are slurping the file into an array. That is completely unnecessary in this case.</p> <pre><code>my $count = 0; my $string = ''; </code></pre> <p>Declare and initialize (if necessary) any variables in the smallest possible scope.</p> <pre><code>my $count; </code></pre> <p>The variable <code>$string</code> is not used anywhere else in your code.</p> <pre><code>foreach $_(@body){ </code></pre> <p>This is silly. <code>for</code> uses $_ if no loop variable is specified. It is easier to keep things straight if you instead specify a lexical loop variable.</p> <pre><code>for my $line ( @body ) { </code></pre> <p>However, I do not think you should slurp the file.</p> <pre><code> if ($_ =~ m/[X]/){ </code></pre> <p>That results in a successful match if the line contains an X. So, it is equivalent to <code>/X/</code>. However, that will not tell you the word that contained the 'X'. For that, you need to decide what a word is and do your matching at the word level.</p> <p>With all that in mind, consider the following script. I have made a simplifying assumption regarding what I consider to be a word. You should be able to build on this to satisfy all the requirements:</p> <pre><code>#!/usr/bin/perl use strict; use warnings; my $filename = "$ENV{TEMP}/test.txt"; open my $input, '<', $filename or die "Cannot open '$filename' for reading: $!"; my $count; while ( my $line = <$input> ) { my @words = grep { /X/ } split /\b/, $line; $count += @words; print join(', ', @words), "\n"; } print "$count\n"; __END__ </code></pre> <p><strong>UPDATE:</strong> If you do not care about finding the words within each line that have one or more X characters, the while loop would be simplified:</p> <pre><code>while ( <$input> ) { $count += (my @matches = /(X)/g ); print if @matches; } </code></pre> <p>by using $_. That, however, is probably inefficient (given that we are saving each matched X character). In this case, <code>tr</code> works best:</p> <pre><code>my ($count, $n); $n = tr/X// and $count += $n and print while <$input>; </code></pre>

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