how to replace multiline text using matlab script which uses perl

Question

I came across a matlab script which uses a perl script called replaceinfile.m which uses

perlCmd = sprintf('"%s"',fullfile('/usr/bin/perl'));
perlstr = sprintf('%s -i.bak -pe"s/%s/%s/g" "%s"', perlCmd, str1, str2,infile);

and wanted to use the replaceinfile function to replace multiple lines of text, e.g.:

Line1
Line2
Line3
Line4

becomes:

Line1
Line4

I tried

replaceinfile('Line2\r\nLine3\r\n','',inputfile,outputfile)

since there are 'CR LF' line endings in my input file but this doesn't work and I can't figure out what the correct regex is.

Any advice? Thanks!

@user1637359 It is an alternation. It matches either `Line1\r\n` _or_ `Line2\r\n`. See [The Stack Overflow regex reference](http://stackoverflow.com/questions/22937618/reference-what-does-this-regex-mean)! — Unihedron, Aug 15 '14 at 16:30

score 2 · Accepted Answer · answered Aug 15 '14 at 15:46

2

You should use \R for matching all Unicode newline sequences. See this regex:

Line[23]\R

Here is a regex demo!

answered Aug 15 '14 at 15:46

Unihedron

Really glad it works for you. :) The technique of using `\R` was covered [here](http://stackoverflow.com/a/25091724/3622940) as well! – Unihedron Aug 15 '14 at 16:28

score 0 · Answer 2 · answered Aug 15 '14 at 15:51

0

The following should work

perlstr = sprintf('%s -i.bak -pe"undef $/; s/%s/%s/g" "%s"', perlCmd, str1, str2,infile);

Maybe it's a good idea to change \r to \r?, then it also works with LF only files.

answered Aug 15 '14 at 15:51

MrTux

2 Answers2