Question

I am writing a perl script. I want to filter out lines that do not match a given regex. The problem is that I can not do that.

I have the following lines:

"com/puppycrawl/tools/checkstyle/Checker" -> "com/puppycrawl/tools/checkstyle/api/SeverityLevelCounter"
"com/puppycrawl/tools/checkstyle/Checker" -> "com/puppycrawl/tools/checkstyle/api/FilterSet"
"com/puppycrawl/tools/checkstyle/Checker" -> "java/util/Locale"
"com/puppycrawl/tools/checkstyle/Checker" -> "com/puppycrawl/tools/checkstyle/api/CheckstyleException"
"com/puppycrawl/tools/checkstyle/Checker" -> "com/puppycrawl/tools/checkstyle/PackageObjectFactory"
"com/puppycrawl/tools/checkstyle/Checker" -> "com/puppycrawl/tools/checkstyle/DefaultContext"
"com/puppycrawl/tools/checkstyle/Checker" -> "com/puppycrawl/tools/checkstyle/api/AutomaticBean"
"com/puppycrawl/tools/checkstyle/Checker" -> "com/puppycrawl/tools/checkstyle/api/FileSetCheck"
"com/puppycrawl/tools/checkstyle/Checker" -> "com/puppycrawl/tools/checkstyle/api/Filter"
"com/puppycrawl/tools/checkstyle/Checker" -> "com/puppycrawl/tools/checkstyle/api/AuditListener"
"com/puppycrawl/tools/checkstyle/Checker" -> "java/lang/StringBuilder"
"com/puppycrawl/tools/checkstyle/Checker" -> "java/lang/Exception"
"com/puppycrawl/tools/checkstyle/Checker" -> "java/io/File"

And I want to remove all those that do not start with com/puppycrawl/tools/checkstyle/ after the ->

So far my script looks like:

#! /usr/bin/perl -s

use File::Find;

our ($roll);

$dir = shift or die("Folder missing\n");
$prefix = shift;


$command = "javap -v";
$extension = "class";
$temp_file = "temp.tmp";

find(\&wanted, $dir);
sub wanted 
{
    if ($_ =~ /\.$extension$/)
    {
        push (@class_files, $File::Find::name);
    }
}

print "digraph G\n{\n";
    print "node [shape=box]\n";

    foreach $class (@class_files) {
        $class=~ s/(.*)\..*/$1/;
        $_result= `$command $class | grep " = class"`;
        $_result=~ s/.*\/\/ */\"$class\" -> /g;

        $_line.=$_result;
    }

    $_line=~ s/"$dir\//"/g;
    $_line=~ s/\[[A-Z]?//g;
    $_line=~ s/\;//g;
    $_line=~ s/->\s*(.*)/-> \"$1\"/g;   

Answer 1

Something like this maybe?

   perl -ne 'print unless /->\s+"com\/puppycrawl\/tools\/checkstyle"/' filename.txt