#39 EOL Converter

Because different operating systems use different EOL conventions, when moving text files from one system to another, you must perform an EOL conversion. This script shows you one way of doing this.

The Code

   1 use strict;
   2 use warnings;
   3
   4 sub usage()
   5 {
   6     print STDERR "Usage $0 <unix|linux|dos|mac|apple>\n";
   7     exit(8);
   8 }
   9
  10 binmode(STDIN);
  11 binmode(STDOUT);
  12
  13 my $eol = "\n";
  14
  15 if ($#ARGV != 0) {
  16     usage();
  17 }
  18 if ($ARGV[0] eq "linux") {
  19     $eol = "\n";
  20 } elsif ($ARGV[0] eq "unix") {
  21     $eol = "\n";
  22 } elsif ($ARGV[0] eq "dos") {
  23     $eol = "\r\n";
  24 } elsif ($ARGV[0] eq "apple") {
  25     $eol = "\r";
  26 } elsif ($ARGV[0] eq "mac") {
  27     $eol = "\r";
  28 } else {
  29     usage();
  30 }
  31
  32 while (1) {
  33     my $ch;     # Character from the input
  34
  35     # Read a character
  36     my $status = sysread(STDIN, $ch, 1);
  37     if ($status <= 0) {
  38         last;
  39     }
  40
  41     if ($ch eq "\n") {
  42         syswrite(STDOUT, $eol);
  43         next;
  44     }
  45
  46     if ($ch eq "\r") {
  47         my $next_ch;    # Check for \r\n
  48         $status = sysread(STDIN, $next_ch, 1);
  49         if ($status <= 0) {
  50             syswrite(STDOUT, $eol);
  51             last;
  52         }
  53
  54         # Check for \r\n
  55         if ($next_ch eq "\n") {
  56             syswrite(STDOUT, $eol);
  57             next;
  58         }
  59
  60         syswrite(STDOUT, $eol);
  61         $ch = $next_ch;
  62     }
  63     syswrite(STDOUT, $ch);
  64 }