Re: split $data, $unquoted

I have the same problem when I want to split CSV files into its columns. The point I got is that I couldn't do it with a regexp, so I did it the way it would be done without regexps...

Basically, I read character by character and push the contexts I enter... For instance....

"This is a column","Yes, I know",12323,23123.23,"This is a \"column\""
[download]

should be splitted in

This is a column
Yes, I know
12323
23123.23
This is a "column"
[download]

ok, no more talking... the code talks by itself...

#!/usr/bin/perl -w

use strict;

my $origin = '"This is a column","Yes, I know",123123,23123.23,"This i
+s a \"column\""';
my @cols = parse_line($origin);
print join("\n", @cols)."\n";

sub parse_line {
    my $line = shift;
    my @contexts;
    my $context = "";
    my $column;
    my @cols;
    my $string_delim = '"';
    my $escape_char = "\\";
    my $field_delim = ',';
    for (my $i = 0; $i < length $line; $i++) {
        my $c = substr($line, $i, 1);
        if ($c eq $string_delim) {
            if ($context eq "string") {
                $context = shift @contexts;
            } elsif ($context eq "escape") {
                $column .= $c;
                $context = shift @contexts;
            } else {
                push @contexts, $context;
                $context = "string";
            }
        } elsif ($c eq $escape_char) {
            if ($context eq "escape") {
                $column .= $c;
                $context = shift @contexts;
            } else {
                push @contexts, $context;
                $context = "escape";
            }
        } elsif ($c eq $field_delim) {
            if ($context eq "string") {
                $column .= $c;
            } elsif ($context eq "escape") {
                $column .= $c;
                $context = shift @contexts;
            } else {
                push @cols, $column;
                undef $column;
            }
        } else {
            $column .= $c;
        }

        if ($i == length($line) - 1) {
            push @cols, $column;
            undef $column;
        }
    }
    return @cols;
}
[download]

daniel

Comment on Re: split $data, $unquoted_value; Select or Download Code

Replies are listed 'Best First'.
Re^2: split $data, $unquoted_value; by motobói (Beadle) on Sep 15, 2005 at 13:33 UTC
Ruoso, wouldn't Text::CSV and related modules (XS, PP) work for you? I suppose you know this module, so what am I missing? `#!/usr/bin/perl -w use Text::CSV_XS; my $csv = Text::CSV_XS->new( { 'escape_char' => '\\' } ); my $line = '"This is a column","Yes, I know",12323,23123.23,"This is a + \"column\""'; if ( $csv->parse($line) ) { print join "\n", $csv->fields, "\n"; } else { print "Could not parse line\n", $csv->error_input, "\n"; }` [download] motobói	[reply] [d/l]
Re^3: split $data, $unquoted_value; by ruoso (Curate) on Sep 15, 2005 at 17:09 UTC
Well... Good question ;)... Maybe I thought it was easier to write the code then looking for a module... how dumb I am... anyway, it was fun to write it... :) daniel	[reply]