I try to filter a csv data file based on some optional columns. This is the expected behavior:

e.g.

data line: "one=1,two=2,three=3,four=4,five=5"
result: $1==1; $2==2; $3==3; $4==4; $5==5

or

data line: "one=1,three=3,five=5"
result: $1==1; $2==''; $3==3; $4==''; $5==5

This is the code I have:

my $string1 = "one=1,two=2,three=3,four=4,five=5";
my $string2 = "one=1,three=3,five=5";

$string1 =~ m/
                (?:one=(.*?),)?
                .*
                (?:two=(.*?),)?
                .*
                (?:three=(.*?),)?
                .*
                (?:four=(.*?),)?
                .*
                (?:five=(.*?),)?
        /x;
print "one: $1, two: $2, three: $3, four: $4, five: $5\n";

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The above code doesn't work as expected neither for string1 nor for string2. I would appreciate your feedback and ideas.

Thank you.

In reply to Regular expressions - match by flaviusm

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