Easy Split

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

Replies are listed 'Best First'.
Re: Easy Split by ikegami (Patriarch) on Jul 03, 2009 at 15:28 UTC
Text::CSV/Text::CSV_XS would do the trick as well. `my $csv = Text::CSV_XS->new ({ binary => 1, sep_char => ':' }); while (my $row = $csv->getline(*ARGV)) { my @fields = @$row; ... } die($csv->error_diag, "\n") if !$csv->eof;` [download]	[reply] [d/l]
Re^2: Easy Split by ropey (Hermit) on Jul 03, 2009 at 15:48 UTC
ok - so does that mean there is no solution just with split?	[reply]
Re^3: Easy Split by liverpole (Monsignor) on Jul 03, 2009 at 16:01 UTC
Hi ropey, If I'm understanding your requirements correctly, you could use a negative-lookbehind assertion like this: `use strict; use warnings; my $string = '111111111:22222\:2222:333333333:4444444'; my @split = split(/(?<!\\):/, $string); print "Results:\n"; map { print "$_\n" } @split;` [download] Which produces this: `Results: 111111111 22222\:2222 333333333 4444444` [download] You'd still need to handle the escaped '\', but the above code at least doesn't split on ':' if it's preceded by '\'. Of course, that doesn't take into account the situation where a backslash '\' is really the second of a pair of backslashes, as in: `my $string = 'AAA:BBB:CCC\\:CCC:DDD";` [download] ... so it's really only a simplistic, partial solution. s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/	[reply] [d/l] [select]
Re^3: Easy Split by ikegami (Patriarch) on Jul 03, 2009 at 16:23 UTC
It means that `$csv->getline` is much simpler, much more readable and much more maintainable than any solution involving `split`, so I didn't see the point of coming up with a solution involving `split`.	[reply] [d/l] [select]
Re^3: Easy Split by massa (Hermit) on Jul 06, 2009 at 17:22 UTC
`split /[^\\](?:\\\\)\K:/, $string` worked Ok for me: it splits on an even number of inverted bars, followed by a colon, but keeps the bars in the split strings. `sub x($) { local($_) = @_; say "\n$_ ==>"; say for split /[^\\](?:\\\\)\K:/, $_ } x $_ for <DATA>; __DATA__ 111111111:22222\:2222:333333333:4444444 111111111:22222\\:2222:333333333:4444444 111111111:22222\\\:2222:333333333:4444444 111111111:22222\\\\:2222:333333333:4444444` [download] Result: `111111111:22222\:2222:333333333:4444444 ==> 111111111 22222\:2222 333333333 4444444 111111111:22222\\:2222:333333333:4444444 ==> 111111111 22222\\ 2222 333333333 4444444 111111111:22222\\\:2222:333333333:4444444 ==> 111111111 22222\\\:2222 333333333 4444444 111111111:22222\\\\:2222:333333333:4444444 ==> 111111111 22222\\\\ 2222 333333333 4444444` [download] Beware that `'222\\:222'` only has ONE inverted bar... :-D []s, HTH, Massa (κς,πμ,πλ)	[reply] [d/l] [select]
Re: Easy Split by Anonymous Monk on Jul 03, 2009 at 14:41 UTC
use Text::xSV, chose : as the separator :)	[reply]
Re: Easy Split by tfoertsch (Beadle) on Jul 03, 2009 at 16:07 UTC
`$ perl -le 'print join "\n", map {s/\\://g;$_} "aa:b\\:b\\::\\:c\\:\\: +c"=~m!(?>\\.\|[^:])+!gs' aa bb cc` [download] `$ perl -le 'print join "\n", map {s/\\://g;$_} "111111111:22222\\:2222 +:333333333:4444444"=~m!(?>\\.\|[^:])+!gs' 111111111 222222222 333333333 4444444` [download] Torsten	[reply] [d/l] [select]
Re^2: Easy Split by ikegami (Patriarch) on Jul 03, 2009 at 16:52 UTC
Why are you removing the colons? `map {s/\\://g;$_}` [download] should be `map { (my $s = $_) =~ s/\\(.)/$1/sg; $s }` [download] Update: hum... The OP did show a lack of colons in the desired output. If that's truly what he wants, `map {s/\\://g;$_}` [download] should be `map { my $s = $_; $s =~ s/\\(.)/$1/sg; $s =~ s/://g; $s }` [download]	[reply] [d/l] [select]
Re: Easy Split by rovf (Priest) on Jul 03, 2009 at 15:56 UTC
First split on the pattern `/[^\\]:/`. This gives you the correct grouping, but leaves you with spurious `\:`. You can use map and `s///` to delete them too, i.e. `map { s/\\://g } split(...)` [download] For completeness: This would fail if a colon can be the very first character in your string. -- Ronald Fischer <ynnor@mm.st>	[reply] [d/l] [select]
Re: Easy Split by ww (Archbishop) on Jul 03, 2009 at 20:20 UTC
No matter how one reads the totality of your node, there's some sort of disconnect between "an escaped : like \: in which case this would not be split on" and the desired output you show. And the mismatch in the number of digits (for example, nine "1"s in `$string` and only 6 in the desired output (that is what the para after the code is, isn't it?) makes it doubly hard to find a single meaning to "would not be split on" do you want to keep the `\:` to lose it but keep the second set of "2"s to lose both (if so, why six "2"s in the output and only 5 in `$string`)? And, just BTW, the colon is NOTescaped in the `$string` you show; since it's single-quoted, you're showing us a literal backslash followed by a colon. Perhaps you can clarify.	[reply] [d/l] [select]
Re: Easy Split by Marshall (Canon) on Jul 06, 2009 at 15:51 UTC
Wow! I guess this wasn't that "easy". It is tricky. `#!/usr/bin/perl -w use strict; my $string = '111111111:22222\:2222:333333333:4444444'; $string =~ s/\\:/:/; #translate \: to just : #the "trick" and its all over now... chomp ($string); #don't worry about trailing \n my @strings = split (/:/,$string); foreach my $line (@strings) { print "$line\n"; } __END__ prints: 111111111 22222 2222 333333333 4444444` [download] Update: the above code produces exactly what the OP asked for, but it could be that 22222\:2222 is a typo and that this "2" string doesn't include a backslash. If so then just split on `[:\n]` or something like that.	[reply] [d/l] [select]
Re^2: Easy Split by massa (Hermit) on Jul 06, 2009 at 17:25 UTC
Trickier than it seems :-D Apparently, the OP wants NOT to split on `'\:'`; so the answer should be: `111111111 22222\:2222 333333333 4444444` [download] []s, HTH, Massa (κς,πμ,πλ)	[reply] [d/l] [select]
Re^3: Easy Split by Marshall (Canon) on Jul 06, 2009 at 17:44 UTC
I think that we have all done a great job of presenting various alternatives. Hooray! I think it is now up to the OP to say what he thinks about our suggestions. I tried. You tried. A bunch of folks have tried. It is pointless for us to argue about what the OP wanted. Let's see what develops. One of the possible scenarios is that the OP says thanks to everybody. We have all tried to help.	[reply]