substitution eats space 1

[facemann]

Hello all.

I am trying to remove unwanted commas from a CSV file. I am attempting to do this by changing any commas that are not contained in parenthesis to a colon character.
The following test program produces an unexpected result:

my $string = '"data","home 966-2815, cell 567-9832","data"';
print "string before sub = $string\n";
$string =~ s/[^"],[^"]/:/g;
print "string after sub = $string\n";

Outputs:

string before sub = "data","home 966-2815, cell 567-9832","data"
string after sub = "data","home 966-281:cell 567-9832","data"


I expected the only the comma after 964-2815 to be deleted but it also deleted the space following the comma. Why and how do I prevent that?

P.S.
The following substitutions also has the same output.

s/[^"],{1}[^"]/:/g;  ## and
s/[^"],{1}?[^"]/:/g;

Facemann

 

[facemann]

Ah, I just noticed that the substituion is eating a character on both sides of the comma!
Hmm....

 

[facemann]

Duh,

The substitution was including the surrounding characters.
The following code does the trick.

my $string = '"data","home 966-2815, cell 567-9832","data"';
print "string before sub = $string\n";
while($string =~ /[^"],[^"]/g){
  my $pos = pos($string);
  substr($string,$pos-2,1) = ':';
}
print "string after sub = $string\n";

 

[azzazzello]

wouldn't this do the same thing (in 1 line)?

$string =~ s/([^"]),([^"])/$1:$2/g;

it just puts the matching characters before and after the comma back where they belong. And you don't need a while loop

 

[ishnid]

TIMTOWDTI:

$string =~ s/(?<!"),(?!")/:/g;