Split Trailing Nulls

p6steve has asked for the wisdom of the Perl Monks concerning the following question:

In my quest to beautify code ... is there a more elegant way to split a csv with trailing nulls into a 2D array than the following?

#Read all transactions
my $lref;
my $line = '';
my @fields = ();
my @alltrans = ();
open( ALL, "<alltrans.csv" ) or die "can't open alltrans.csv";
while( <ALL> ) {
    chomp;
    $line = $_ . ' ';    #ugly as only copes with one trailing null fi
+eld
    @fields = split( ',', $line );
    $fields[-1] = ( $fields[-1] eq ' ' ) ? '' : $fields[-1];
    $lref = [ @fields ];
    push( @alltrans, $lref );
}
close ALL;
print Dumper @alltrans;
[download]

Comment on Split Trailing Nulls Download Code

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Re: Split Trailing Nulls by delirium (Chaplain) on Feb 07, 2004 at 15:00 UTC
Most CSV-related posts end up with an obligatory reference to Text::CSV or a similar module, and a reminder about the CSV format. Here's mine: If your data is really CSV data, don't forget to take into account the possibility of bizarre quoted constructs, such as Field 1,"""This is quoted,"" and this isn't", Field 3 Splitting on a comma with real CSV data is unsafe. Consider a module such as the above link, or use another method of dividing the fields. Here's mine, which is ugly but workable: `sub csv_split { local $_ = shift \|\| return undef; my @array = (); my $count = my $quoted = 0; while ( s/(.)// ) { my $char = $1; if ($char eq ',' && !$quoted) { $count++; next; } if ($char eq q/"/) { unless ( $quoted && s/^\"// ) { $quoted = 1 - $quoted; nex +t; } } $array[$count] .= $char; } return @array; }` [download]	[reply] [d/l]
Re: Split Trailing Nulls by Roger (Parson) on Feb 07, 2004 at 13:25 UTC
You can read about split by typing: `perldoc -f split` [download] Set the LIMIT of split to -1 to preserve trailing nulls. `open ALL, "alltrans.csv" or die "Can not open file: $!"; while (<ALL>) { chomp; push @alltrans, [ split /,/, $_, -1 ]; } close ALL;` [download] I would even write it as a one-liner, but that's a matter of personal taste: `my @alltrans; chomp, push @alltrans, [ split /,/, $_, -1 ] for <ALL>; # or my @alltrans = map { chomp; [ split /,/, $_, -1 ] } <DATA>;` [download]	[reply] [d/l] [select]