This simple piece of code should do the trick for you... 
open FILE, 'test_file.txt' || die "$!\n";
my $text = join( '', @{ [ <FILE> ] } );
close FILE;

die "The file supplied is not of unix format!\n" if ( $text =~ /\r\n/ 
+);

[download]
You might not want to take this snippet as literal, for it will load the entire contents of the file into memory and test the entite thing. This will be quite inneficient. However, this should give you the general idea of how to do what you are looking for.

Update:
I might as well give you an example of something that will be, possibly, a little less memory intensive: 
open FILE, 'test_file.txt' || die "$!\n";
while ( my $line = <FILE> ) {
  die "File is not of UNIX format!\n" if ( $line =~ /\r\n/ );
  last;
}
close FILE;

[download]
This one will only check the first line for Windows format. If it finds it, it will die; otherwise will simply move on with the rest of the application.

Good Luck!

---hA||ta----
print map{$_.' '}grep{/\w+/}@{[reverse(qw{Perl Code})]} or die while ( 'trying' );

In reply to Re: Determine whether file is dos or unix format by wazzuteke
in thread Determine whether file is dos or unix format by fritzvtb

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