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POHow can I detect a blank line in Perl?
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  1. POHow can I detect a blank line in Perl?
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    copied!<ul> <li><p>How do I check a line ($_ value) is a blank line in Perl? Or another good method to check it instead of using $_?</p> <p>I want to code like this</p> <p>if ($_ eq '') # Check current line is a blank line (no any characters) { $x = 0; }</p></li> </ul> <hr> <p>I updated some code with a question solution below.</p> <p>My <strong>test.txt</strong> for parsing:</p> <pre><code> constant fixup private GemAlarmFileName = &lt;A "C:\\TMP\\ALARM.LOG"&gt; vid = 0 name = "" units = "" constant fixup private GemConfigAlarms = &lt;U1 0&gt; /* my Comment */ vid = 1 name = "CONFIGALARMS" units = "" min = &lt;U1 0&gt; max = &lt;U1 2&gt; default = &lt;U1 0&gt; </code></pre> <p>My code is below.</p> <p>That's why I need to initially set $x = 0. I am not sure if it is a normal solution or not.</p> <pre><code> sub ConstantParseAndPrint { if (/^$/) // SOLUTION! { $x = 0; } if ($x == 0) { if (/^\s*(constant)\s*(fixup|\/\*fixup\*\/|)\s*(private|)\s*(\w+)\s+=\s+&lt;([a-zA-Z0-9]+)\s+(["']?)([a-zA-Z0-9.:\\]+)\6&gt;\s*(\/\*\s*(.*?)\s*\*\/|)(\r|\n|\s)/) { $name1 = $1; # Constant $name2 = $2; # Fixup $name3 = $3; # Private $name4 = $4; $name5 = $5; $name6 = $7; $name7 = $8; # start print if (!$name7 eq '') { print DEST_XML_FILE "&lt;!-- $name7--&gt;\n"; } print DEST_XML_FILE " &lt;ECID"; print DEST_XML_FILE " logicalName=\"$name4\""; print DEST_XML_FILE " valueType=\"$name5\""; print DEST_XML_FILE " value=\"$name6\""; $x = 1; } } elsif ($x == 1) { if(/\s*vid\s*=\s*(.*?)(\s|\n|\r)/) { $nID = $1; print DEST_XML_FILE " vid=\"$nID\""; $x = 2; } } elsif ($x == 2) { if(/\s*name\s*=\s*(.*?)(\s|\n|\r)/) { $nName = $1; print DEST_XML_FILE " name=$nName"; $x = 3; } } elsif ($x == 3) { if (/\s*units\s*=\s*(.*?)(\s|\n|\r)/) { $nUnits = $1; print DEST_XML_FILE " units=$nUnits"; $x = 4; } } elsif ($x == 4) { # \s+&lt;([a-zA-Z0-9]+)\s+([a-zA-Z0-9]+)&gt;\ if (/\s*min\s*=\s+&lt;([a-zA-Z0-9]+)\s+([a-zA-Z0-9]+)&gt;(\s|\n|\r)/) { #$nMinName1 = $1; $nMinName2 = $2; # Find the nMin Value #$nMinName3 = $3; #$nMinName4 = $4; print DEST_XML_FILE " min=\"$nMinName2\""; $x = 5; } else { print DEST_XML_FILE "&gt;&lt;/ECID&gt;\n"; $x = 0; # There is no line 4 and line 5 } } elsif ($x == 5) { if (/\s*max\s*=\s+&lt;([a-zA-Z0-9]+)\s+([a-zA-Z0-9]+)&gt;(\s|\n|\r)/) { #$nMaxName1 = $1; $nMaxName2 = $2; # Find the nMax Value #$nMaxName3 = $3; #$nMaxName4 = $4; print DEST_XML_FILE " max=\"$nMaxName2\""; $x = 6; } } elsif ($x == 6) { if (/\s*default\s*=\s+&lt;([a-zA-Z0-9]+)\s+([a-zA-Z0-9]+)&gt;(\s|\n|\r)/) { #$nDefault1 = $1; $nDefault2 = $2; # Find the default Value #$nDefault3 = $3; #$nDefault4 = $4; print DEST_XML_FILE " default=\"$nDefault2\"&gt;"; print DEST_XML_FILE "&lt;/ECID&gt;\n"; $x = 0; } } } </code></pre>
 

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