CODEWITHSUNDEEP
regexperl
searcot jabali
searcot jabali

Reputation: 438

Perl regex substitution

I need to match exactly "", but not ,"", for example in this string

"abc","123","def","","asd","876"",345

I need to substitute the "", following the "876" but leave the "" after "def" alone.

The regex I have right now is 

$line =~ s/[^,]"",/",/g

However this substitutes the 6 from "876".

Upvotes: 0

Views: 65

Answers (3)

James Aanderson
James Aanderson

Reputation: 330

This converts the broken col to an empty col and double quotes the last column. Not quite sure if that is what your looking for but there you go. 

use strict ;

my $line = '"abc","123","def","","asd","876"",345' ;

$line =~ s/\,{0,1}\"\"\,/\,\"\"\,/g ;
my @foo = split(/\,/,$line) ;
$foo[$#foo] =~ s/^|$/\"/g ;
$line = join ",", @foo ;

print "\n$line\n" ;

Upvotes: -1

rustyx
rustyx

Reputation: 85531

Use a group replacement:

$line =~ s/([^,])"",/$1",/g

Or a lookbehind:

$line =~ s/(?<!,)"",/",/g

Having said that, "" is a CSV quoted quote, it can appear inside a string. For example, this is valid: """abc""". To avoid breaking that, also exclude " from the lookbehind:

$line =~ s/(?<![,"])"",/",/g

Upvotes: 2

Andrey
Andrey

Reputation: 1818

You are trying to fix a broken CSV file. Doing it with a pattern match is not the best solution. You should try fixing it by using Text::CSV_XS module with allow_loose_quotes => 1 option.

Upvotes: 0

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