Counting number of double quotes in a string

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

Hi Monks,

I'm reading a file (each line has many fields enclosed by
double quotes). I want to count the number of double quotes
in each line. The fields are separated by commas(,) but I
cannot use this as separator as field also may have the
comma as part of its string. So to cross check the number
of fields in a record (line) I am counting the number of
double quotes. So far good. I have the following code,
which is hanging. Syntax seem to be ok, but still this is
a problem. Any suggestions ?

open(FILENAME,"c:\\abc.txt") || die "Cannot Open the file.\n" ;
my $quote_count = 0 ;
my $pos = 0 ;
my $record = "" ;
while(<FILENAME>) {
    $record = $_ ;
    chomp $record ;
    while ($pos = index($record, '"', $pos) != -1) {
        $quote_count++;
        $pos++;
    }
}
print "Number of double quotes are $quote_count\n";
close FILENAME ;
[download]

The file abc.txt has following data (just 2 lines)

"11111","xxxx","yyyy","222, world drive"
"22222","abc","jkl","my road, my world"

What is causing the hanging of the process ? pls let me know.

Thanks in advance,

Raj.

Comment on Counting number of double quotes in a string Download Code

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Re: Counting number of double quotes in a string by japhy (Canon) on May 10, 2002 at 22:26 UTC
It's a problem with precedence: `friday:~ $ perl -MO=Deparse,-p -e '1 while $x = $y != $z' -e syntax OK '???' while ($x = ($y != $z));` [download] As you can see, you're doing `$pos = (index() != -1)`, where you want to do `($pos = index()) != -1`. This problem causes `$pos` to be 1 all the time! I have a better idea. Use the `tr///` operator. `$count += tr/"// while <FILE>;` _____________________________________________________ Jeff`[japhy]`Pinyan: Perl, regex, and perl hacker, who'd like a job (NYC-area) `s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;`	[reply] [d/l] [select]
Re: Re: Counting number of double quotes in a string by arajani (Novice) on May 13, 2002 at 16:54 UTC
Hi Japhy, I realised the folly of not careful about the precedence. Thanks a lot and appreciate the help. Regards, Raj.	[reply]
Re: Counting number of double quotes in a string by thelenm (Vicar) on May 10, 2002 at 22:23 UTC
You will probably want to check out the Text::CSV_XS module, which can do parsing of CSV files for you and will make your life a lot easier. But to answer your question directly, to count the number of double-quote characters in a line, do this: `$count = ($line =~ y/"//);` [download]	[reply] [d/l]
Re: Counting number of double quotes in a string by mephit (Scribe) on May 11, 2002 at 03:28 UTC
Like I suggested in reply to this question, Text::Parsewords might do the trick. I've never used the CSV module mentioned in another reply, so I wouldn't know how to go about using it to solve this problem, but it should be possible with ParseWords.	[reply]