I understand Marshall and Huck solution, but not sure tybalt89 solution.

Don't worry, tybalt89 has the nasty habbit of posting completely uncommented, unexplained code that may or may not work; sometimes it works only accidentally.

Your best bet for handling CSV data is to use Text::CSV_XS, its slower pure-perl implementation Text::CSV, or DBI in combination with DBD::CSV. The latter pair uses Text::CSV_XS behind the scenes to provide an SQL interface to the data in CSV files.

Alexander

Text::CSV_XS, its slower pure-perl implementation Text::CSV

From the doc of the latter:

Text::CSV is a thin wrapper for Text::CSV_XS-compatible modules now. ... Text::CSV uses Text::CSV_XS by default, and when Text::CSV_XS is not available, falls back on Text::CSV_PP, which is bundled in the same distribution as this module.

Personally, I usually recommend Text::CSV, although I guess I should start telling people to make sure Text::CSV_XS is installed as well :-)

Text::CSV is a thin wrapper for Text::CSV_XS-compatible modules now.

Of course, you are right. But one or one and a half decades ago, when I had to handle CSV files from Perl for the first time, Text::CSV was what now is Text::CSV_PP. That's written to my biological persistent storage, and it's damn hard to update. ;-) I know that, because it's not the first time that someone had to remind me.

Alexander

--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

I love to use the one you recommend but I am just a beginner so not sure how to apply See if you can help me to edit my code below I like to change the value in column one to a fix value. Any number should reduced by 1 except "1" becomes "P". I am trying to learn how to use map or grep not creating the hash, that the guys showed me. Thanks Macy

"Header1","Header2",Header3"
"A123","1","valueB1"
"B234","1","valueB2"
"C345","2","valueB3"
"D456","3","valueB4"
"E567","4","valueB5"
"F678","5","valueB6"
[download]

and the output should be

"Header1","Header2",Header3"
"A123","P","valueB1"
"B234","P","valueB2"
"C345","1","valueB3"
"D456","2","valueB4"
"E567","3","valueB5"
"F678","4","valueB6"
[download]

here is my code

open my $fh1,'<',"NRoomch.txt";
my @a = <$fh1>; 
my @arr;
 for  $i (0..$#a){
  my @b = split(/,/,$a[$i]);
    for $j (0..$#b) {
        $b[$j] =s~/"//g;
if ($j==1 && my @arr = grep { $_ =~ /\"1"$/ } @b);
        @arr = map{$_ = "P"} @arr;            
        else
        @arr = map {$b[$j] - 1} (1..$#b);
        print @arr;
    };
 };
close($fh1);
[download]

I am just a beginner so please be patient with me,thanks. Macy