CheckTxt

#! /usr/bin/perl

# This is a script for checking whether a file contains any carriage return
# characters, and whether it is valid UTF-8.

use Encode;

# This subroutine does the work for one file.

$yield = 0;
$ascii = 0; # bool
$crlf = 0; # bool

sub checktxt {
my($file) = $_[0];
open(IN, "<:raw", "$file") || die "Can't open $file for input";
$bin = do { local $/ = undef; <IN> };
close(IN);
my $data;
eval
  {
  $data = Encode::decode("UTF-8", $bin, Encode::FB_CROAK);
  1; # return true
  }
or do
  {
  printf "Bad UTF-8 in $file\n";
  $yield = 1;
  return;
  };
if (!$crlf && index($data, "\r") != -1)
  {
  printf "CR in $file\n";
  $yield = 1;
  }
if ($ascii && $data =~ /[^\x01-\x7e]/)
  {
  printf "Non-ASCII in $file\n";
  $yield = 1;
  }
}

# This is the main program

$, = "";   # Output field separator
for ($i = 0; $i < @ARGV; $i++)
  {
  if ($ARGV[$i] eq "-ascii")
    {
    $ascii = 1;
    }
  elsif ($ARGV[$i] eq "-crlf")
    {
    $crlf = 1;
    }
  else
    {
    checktxt($ARGV[$i]);
    }
  }

exit $yield;

# End