A perl script that finds BOM from the files under the directory specified.

findBOM.pl

use strict;
use warnings;

my $dir = $ARGV[0];
if((!$dir) or (! -d $dir)) {
    die "Need to specify a directory.";
}

my $isFound = 0;
checkBomFrom($dir);
if ($isFound == 0) {
    print "No files which include BOM.";
}

sub checkBomFrom {
    my $dir = shift;
    opendir(my $in, $dir) or die "Failed to open $dir: $!";
    my @fileList = readdir($in);
    closedir($in);
    
    foreach my $file (@fileList){
        if($file =~ /^\.{1,2}$/){
            next;
        }
        if( -d "$dir\\$file"){
            checkBomFrom("$dir\\$file");
        }
        else{
            printFileNameIfIncludeBom("$dir\\$file");
        }
    }
}

sub printFileNameIfIncludeBom {
    my $file = shift;
    if(-f $file) {
        open(my $in, $file) or die "Failed to open $file: $!";
        my $firstLine = <$in>;
        close($in);
        return if (!$firstLine);
        
        if($firstLine =~ /^\xef\xbb\xbf/) {
            print $file;
            if ($isFound == 0) {
                $isFound = 1;
            }
        }
    }
}