Re: nth field extraction

I'm not sure why you can't use plain split for that?

my $major_div = '!!';
my $user_div = ';';
my $var_div = ',';
my $full_string = 'abcd-efgh-ijkl-mnop;key1=data1,key2=data2;key1=data
+3,key2=data4!!qwer-asdf-zxcv-tyui;key1=data3;key3=data6!!trew-hgfd-yt
+re-bvcx;key1=data7,key2=data8;key1=data9,key2=data10!!erty-dfgh-cvbn-
+hjkl;key2=data5;key3=data6';

sub field_split {
    my ($sep, $field, $source) = @_;
    return (split /\Q$sep/, $source)[ $field-1 ]
};

my $major_field = &field_split($major_div, 3, $full_string);
my $user_key = &field_split($user_div, 1, $major_field);
my $user_vars1 = &field_split($user_div, 2, $major_field);
my $user_vars2 = &field_split($user_div, 3, $major_field);
my $key_data = &field_split($var_div, 1, $user_vars1);
[download]

But really, I would look at using Text::CSV_XS to read in the incoming (major) data and split it up into an array, and then split up the minor fields from that.

Comment on Re: nth field extraction Download Code

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Re^2: nth field extraction by lee_crites (Scribe) on Jul 27, 2018 at 14:39 UTC
Thanks for the (probably obvious) pointer into using a variable in the split command. If I was writing this today, I'd probably have checked to see if that was a possibility. I have a vague memory from back when I wrote the function (15+/- years ago), and couldn't get that construct working. I was just thinking about that, and remembered that the reason I wrote this was to deal with migrating data from a PICK system to a *nix system, back in the 90's -- so it is a tad older than 15 years... :O Thanks for the help! Lee Crites lee@critesclan.com	[reply]
Re^3: nth field extraction by AnomalousMonk (Archbishop) on Jul 29, 2018 at 18:43 UTC
Further to Marshall's post: For more info on `\Q \E` (and their `\L \l \U \u` pals), see also perlop, perlre and quotemeta. Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]
Re^3: nth field extraction by Marshall (Canon) on Jul 29, 2018 at 18:18 UTC
Thanks for the (probably obvious) pointer into using a variable in the split command. If I was writing this today, I'd probably have checked to see if that was a possibility. I have a vague memory from back when I wrote the function (15+/- years ago), and couldn't get that construct working. You might have not recognized the significance of \Q in `return (split /\Q$sep/, $source)[ $field-1 ]);` The \Q says to ignore any characters in $sep that would otherwise mean something to the regex engine. I often use a \Q...\E pair for this just to highlight this situation. Anyway without \Q, if $sep contains something that matters to the regex engine, you will get confusing results.	[reply] [d/l]