Well, considering the OP only wants files from one particular directory, he doesn't need the -r option.

But grep is still the way to go though.

The first place to look is glob, since it appears that you don't want to recurse down a directory tree. As an example (NOT TESTED)

# insert appropriate shebang line

use strict;
use warnings;

my @files = glob("chat/*.htm"); # use something like [Hh][Tt][Mm] if y
+ou're unsure about the case

@files = grep { -s $_ and -f _ and -r _} @list;

print "Enter search string :";

my $string = <>; # read from STDIN

chomp($string);  # strip off the line feed resulting from <enter>

my $quoted_string = quotemeta($string);  # quote all meta-characters. 
+ Remove if not needed

foreach my $file (@files) {

    my $filehandle;

    unless(open($filehandle, "<", $file)) {
         warn "Could not open $file because $!\n";
         next;
    }

    my @contents = <$filehandle>; # presuming the files are not too la
+rge

    chomp(@contents);
    close($filehandle) or die "Could't close $file because $!\n";


    @contents = grep { /$quoted_string/ } @contents;

    if(@contents){
       print "$string was found in $file:\n\t",join("\n\t",@contents),
+"\n";
   }
}
[download]

use File::Find::Rule

sub fullPathToFile #($StartDirectory,$SearchExpression)
{
    my ($StartDirectory,$SearchExpression)= @_;
    my(@files,$IsWin1,$IsWin2,@File_Paths,$Fl,@d,$c);
    @files = File::Find::Rule->file()->name("$SearchExpression")->in("
+$StartDirectory");
    $IsWin1=substr($StartDirectory,1,1);
    $IsWin2=substr($StartDirectory,0,2);
      #If $StartDirectory starts with D:\ or \\\\ than it is Win repla
+ce / with \
      if(($IsWin1 eq ':')||($IsWin2 eq '\\\\'))
      {
        foreach $Fl (@files) 
        {
          @d=split(/\//,$Fl);
          $c=join ("\\",@d);
          push(@File_Paths,$c);
        }
      }
      else
      {
        @File_Paths=@files;
      }
return @File_Paths;
}

$LocationOfTheStartDir='C:\chat';
$SearchExp='*.htm';
@AllFilePaths=fullPathToFile($LocationOfTheStartDir,$SearchExp);

foreach $InputFile (@AllFilePaths){
@AllLinesFromTheFile = `type $InputFile`;
    foreach $line (@AllLinesFromTheFile){
        if ($line=~/DesiredString/){
            print "$line";
        }

    }
@AllLinesFromTheFile=();
}
[download]

No help got only this Software error: syntax error at testi7.cgi line 8, near "use File::Find::Rule sub fullPathToFile #($StartDirectory,$SearchExpression) " Execution of testi7.cgi aborted due to compilation errors.

Put a semicolon after use File::Find::Rule in your code, missing from OP.

Most likely you have not installed File::Find::Rule Try this code without calling any modules

sub fullPathFileName #($StartDirectory,$RegularExpression)
{
    #my ($StartDirectory,$WhildCardSearch)= @_;
    my ($StartDirectory,$RegularExpression)= @_;
    my(@A,$e,$C,@B,$a,@C,@Dir,$InputDir,@AllTestSuitefiles,@TestSuitef
+iles,$p,@FullPath);
    #Purpose is to extract all paths to directories and subdirectories
    @A=`dir $StartDirectory /s/w ` ;
      foreach $e (@A)
      {
        $C=substr($e,0,10);
        #Extract only string that starts with Directory
        if($C eq " Directory")
        {
          push(@B,$e);
        }
      }
       # Directory of C:\cr1_qc\crnqcV3\CM\Bering\Results\object_test_
+mssql\Root\DirectorySuite\GroupsandRolesSuite\OutputPages
       # I want to start from  C:

      foreach $a (@B)
      {
        push(@C,substr($a,14));
      }
    #Remove lash char that is whitespace
    @Dir=trim(@C);

      foreach $InputDir (@Dir)
      {
        opendir(ODH,"$InputDir")|| die "Can't open dir\n";
        @AllTestSuitefiles=readdir(ODH);
        #  @TestSuitefiles=glob("$WhildCardSearch");
        closedir(ODH);
        # Find all  files
        @TestSuitefiles=grep(m/$RegularExpression/,@AllTestSuitefiles)
+;

        foreach $p (@TestSuitefiles)
        {
          push(@FullPath,"$InputDir\\$p");
        }
      }
return  @FullPath;
}#fullPathFileName

$LocationOfTheStartDir='C:\chat'; 
$SearchExp='*.htm';   
@AllFilePaths=fullPathToFile($LocationOfTheStartDir,$SearchExp);

foreach $InputFile (@AllFilePaths){
@AllLinesFromTheFile = `type $InputFile`;
    foreach $line (@AllLinesFromTheFile){
        if ($line=~/DesiredString/){
            print "$line";
        }

    }
@AllLinesFromTheFile=();
}
[download]

(: Life is short enjoy it :)