I had a need for a piece of my software to be platform independent when reading/writing files with any type of line endings. So, I'm sure there are better/more efficient ways to do this, but I couldn't find one and really wanted to better understand record separators, so I wrote File::Edit::Portable.

This module will read in a file on any platform, save the existing record separators (line endings), and modify them to the local platforms endings for use. It'll return either a file handle or an array of the file contents.

You can optionally then push back an array of contents, and the module will rewrite the file (or optionally a new one), using the line endings that were found while reading (or optionally a user supplied one). This means it'll open Unix files on Windows and rewrite the file with Unix endings, and vice-versa on Windows and Mac (the three I've tested).

use warnings;
use strict;

use File::Edit::Portable;

my $rw = File::Edit::Portable->new;

my $recsep;

$recsep = $rw->recsep('unix.txt');
print "unix file before write: $recsep\n";

$recsep = $rw->recsep('win.txt');
print "win file before write: $recsep\n";

my $ufh = $rw->read(file => 'unix.txt');
my @unix_contents = <$ufh>;
close $ufh;

$rw->write(contents => \@unix_contents);
$recsep = $rw->recsep('unix.txt');
print "unix file after rewrite: $recsep\n";

my $wfh = $rw->read(file => 'win.txt');
my @win_contents = <$wfh>;
close $wfh;

$rw->write(contents => \@win_contents);
$recsep = $rw->recsep('win.txt');
print "win file after rewrite: $recsep\n";
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Output:

# unix

$ ./find.pl

unix file before write: \0a
win file before write: \0d\0a
unix file after rewrite: \0a
win file after rewrite: \0d\0a

# windows

E:\test>perl find.pl

unix file before write: \0a
win file before write: \0d\0a
unix file after rewrite: \0a
win file after rewrite: \0d\0a
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We've also got a non-OO interface:

use File::Edit::Portable qw(pread pwrite);

my $fh = pread('file.txt');

# or even

my @contents = pread('file.txt');

# then, later

pwrite('file.txt', \@contents);
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I definitely know it's quite inefficient, but it's my first working prototype. There are a lot of things missing (unicode and open filters for instance). Criticisms or existing ways to do this are very welcome.

-stevieb