in reply to Re: finding different linebreaks with <>
in thread finding different linebreaks with <>

OK, cool thank you for your prompt replies.
So, i finally get the file to output, line by line, with this code:

#!/usr/bin/perl - w
use strict;

local $/="\cM";
my $file = $ARGV[0];
open my $fh, '<', $file or die $!;
while(<$fh>){
print $_."\n";
}

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I had to add the "\n" to the end of each line so that it printed out correctly in the unix system, the reason given by you guys

However, what if my file could be EITHER *nix/mac or windows, what's the best way to tell??

I'm hoping you can use a regular expression with the '$/' and do something like this:

local $/ = "[\n\r\cM]";

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which then gets regexp for any or either, does that make sense?

Cheers
Sam

Replies are listed 'Best First'.
Re: Re: Re: finding different linebreaks with <>
by hardburn (Abbot) on Apr 08, 2004 at 20:20 UTC

    Sorry, no regexen are allowed in $/.

    The best solution is to convert the data file into a consistant form before the main program gets it.

    ----
    : () { :|:& };:

    Note: All code is untested, unless otherwise stated

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      no regexen are allowed in $/.

      You missed a chance to quote perlvar:

      Remember: the value of $/ is a string, not a regex. awk has to be better for something. :-)

      ($_='kkvvttuubbooppuuiiffssqqffssmmiibbddllffss')
      =~y~b-v~a-z~s; print
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      I understand, that I will do, thanks for your help
      Sam
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Re: Re: Re: finding different linebreaks with <>
by tilly (Archbishop) on Apr 09, 2004 at 01:20 UTC
    You can do exactly what you asked for with File::Stream. A moderately portable regular expression to use is qr/\r\n?|\n\r?/. That should handle Unix, DOS and MacOS line endings on any of those three platforms.
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      Dear Tilly,

      Thanks so much for your help, I've downloaded and used File::Stream to great success. I'm using the regular expression below: 

      my ($handler, $stream) = File::Stream->new(\*FILE, separator => qr{[\c
+M\r\n][\cM\r\n]?});

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      Does anyone see any pitfalls with this one? I wanted to make sure I got all three 'types' of characters.

      Thanks
      Sam

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        That RE will incorrectly read 2 returns as just one.
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Re: Re: Re: finding different linebreaks with <>
by Anomynous Monk (Scribe) on Apr 08, 2004 at 23:07 UTC
    Nope, no regexes for $/. If the file isn't too large or performance isn't too critical, you could do something like (untested, and requires 5.8.0): 
    open my $fh, "filename" or die $!;
while (my $line = <$fh>) {
   local $/ = "\r";
   open my $fh, "<", \$line or die $!;
   while (my $line = <$fh>) {
      # process $line here
   }
}

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    Otherwise, open the file and read a bunch of characters (e.g. by setting $/=\1024; see perldoc perlvar) and check for \n or \r (e.g. with $/ = $1 if $buffer=~/([\r\n])/;)and set $/ appropriately; then seek to the beginning of the file and start the read loop.
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