Text::CSV and escaped quotes

mldvx4 has asked for the wisdom of the Perl Monks concerning the following question:

Thanks, Tux, for Text:CSV. It keeps coming in handy both directly and indirectly.

I have a question about escaped quotes in incoming files. I would have expected the output for the three data lines below to be identical, but the second line misses the escaped single quote. Is an escaped single quote some kind of faux pax or even a mistake within the data or would it be one in something which Text::CSV draws on?

#!/usr/bin/perl

use Text::CSV qw(csv);

use strict;
use warnings;

my $csv = Text::CSV->new ({ binary => 1, auto_diag => 1 });
my $o = \*STDOUT;

# Read/parse CSV
while (my $row = $csv->getline (\*DATA)) {
    my @selected = ( splice(@{$row}, 0, 2), splice(@{$row}, -6, 2) );
    $csv->say($o, \@selected);
}

exit(0);

__DATA__ 
8, 9, NULL, 'Filler', '555-999', '77:88', 0, 0, 0, 0
8, 9, NULL, 'Filler', '555-999', '77:88', 'A \' B , C', 0, 0, 0
8, 9, NULL, 'Filler', '555-999', '77:88', 0, 0, 0, 0
[download]

This is based on something found in the wild.

Comment on Text::CSV and escaped quotes Download Code

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Re: Text::CSV and escaped quotes by swl (Prior) on Sep 29, 2023 at 00:00 UTC
Check the escape_char setting. Adding this line after the loop shows `"` is the escape_char. `say $csv->escape_char;` Getting it to import also needs a few other settings, so perhaps the `auto_diag` process needs work, or this is just difficult data to auto diagnose. I also re-arranged the code to work on my machine and added a `use 5.010;`. use strict; use warnings; use 5.010; use Text::CSV qw(csv); my $csv = Text::CSV->new ({ binary => 1, auto_diag => 1, escape_char => '\\', quote_char => "'", allow_whitespace => 1 }); my $o = \STDOUT; # Read/parse CSV while (my $row = $csv->getline (\DATA)) { my @selected = ( splice(@{$row}, 0, 2), splice(@{$row}, -6, 2) ); $csv->say($o, \@selected); } say $csv->escape_char; exit(0); __DATA__ 8, 9, NULL, 'Filler', '555-999', '77:88', 0, 0, 0, 0 8, 9, NULL, 'Filler', '555-999', '77:88', 'A \' B , C', 0, 0, 0 8, 9, NULL, 'Filler', '555-999', '77:88', 0, 0, 0, 0 [download]	[reply] [d/l] [select]
Re^2: Text::CSV and escaped quotes by mldvx4 (Friar) on Sep 29, 2023 at 00:20 UTC
Thanks. Setting both the `escape_char` and the `quote_char` does it. I had not realized the necessity of doing that explicitly. `escape_char => '\\', quote_char => "'",` [download] I guess the general (mis-)use of CSV is complicated by the reality that "there is no formal specification in existence, which allows for a wide variety of interpretations of CSV files". ODF was supposed to ameliorate this problem, but 1) the devil is in the details, 2) ODF is more complex, and 3) it got squelched by the usual adversary of open standards.	[reply] [d/l] [select]
Re^3: Text::CSV and escaped quotes by NERDVANA (Priest) on Sep 30, 2023 at 07:30 UTC
The one I keep running into is where they don't bother escaping anything, and just hope the quotes work out. There's a setting for that too!	[reply]
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