CODEWITHSUNDEEP
regexperlawksed
chrise
chrise

Reputation: 63

Trying to replace \r\n\n but not \r\n in a file

This is using GNU sed version 4.2.1 but I've also tried awk and Perl without any success so far.

I have a file that is produced by a COBOL program (on Linux) and it has what can be considered nonstandard CRLF instead of LF (CRLF of course being Windows line terminators) but that's what I need to retain - anything CRLF stays.

So \r\n sequences stay.

What I need to replace are occasional \r\n\n sequences with \r\n\r\n without disturbing anything else.

I have to match this file I produce using diff with the original file produced on BSD or SCO or something.

This doesn't work and I expect the first /n is getting stripped by Sed as the line terminator

sed -e 's/\r\n\n/\r\n\r\n/g'  infile  > outfile

I tried hex 0x and also double escape too

Thanks for any suggestions

Upvotes: 1

Views: 316

Answers (5)

Robin Hsu
Robin Hsu

Reputation: 4504

Try unix2dos utility: It handle all unix/dos/ and mixture of unix/dos cases. Note: dos2unix is also a good utility.

Overwrite:

unix2dos your-file

Create new file:

unix2dos < your-file > your-new-file

Upvotes: 0

Ed Morton
Ed Morton

Reputation: 203985

WIth GNU awk for multi-char RS:

awk -v RS='\r\n\n' -v ORS='\r\n\r\n' '1' file

Upvotes: 0

glenn jackman
glenn jackman

Reputation: 247012

sed being a line oriented tool, blah\r\n\n will be a line blah\r followed by an empty line. So, add a \r to any empty line:

sed 's/^$/\r/' infile > outfile

Upvotes: 2

mvp
mvp

Reputation: 116317

Just use this Perl one-liner:

perl -pe "s/\R/\r\n/g" <input.txt >output.txt

Magic here is about \R which matches any new-line combination accepted by Perl: \n, \r\n or \r alone. As far as I know, \R is Perl-only - not supported by sed or awk.

Upvotes: 0

Borodin
Borodin

Reputation: 126742

I suggest you just add a CR before any LF that isn't already preceded by one.

s/ (?<!\r) (?=\n) /\r/xg

In a program that alters the data in a file it would look something like this

use strict;
use warnings;

use open IO => ':raw';

my $data = do {
  local $/;
  <>;
};

$data =~ s/ (?<!\r) (?=\n) /\r/xg;

print $data;

and you would run it like

perl add_cr.pl myfile > newfile

or, if you wanted to modify your file in-place (after testing it) you could use just

perl -i add_cr.pl myfile

Upvotes: 2

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