Re: Regexp: How to match in middle but not the ends?

Don't use $&! It slows down all the regexp in your program (including modules) that don't have captures. Use captures instead.

while ($string =~ /([CSH][CSHL]*[CSH])/g) {
    print "$1, ";
}
[download]

Use join to avoid the trailing comma.

print join ', ', $string =~ /([CSH][CSHL]*[CSH])/g;
[download]

An alternative approach would be to strip out the offending L characters.

for ($string) {
   s/-L+|L+-/-/g;
   s/^L+//;
   s/L+$//;
   print join ', ', /([CSHL]{2,})/g;
}
[download]

Update: Added s/^L// and s/L$//.
Update: Changed L to L+.
Update: Accidently changed too many things to "+"s. Fixed.

Comment on Re: Regexp: How to match in middle but not the ends? Select or Download Code

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Re^2: Regexp: How to match in middle but not the ends? by Skeeve (Parson) on Jul 30, 2006 at 16:59 UTC
If you strip the L, don't forget (like I did first) to strip an L at the start and end of the string. You should also use "+" to strip any sequence of L. I think, this will do: `s/(?:^L+)\|(?:-L+)\|(?:L+-)\|(?:L+$)/-/g` (I used (?:) because I'm currently too busy (lazy) to test... `s$$([},&%#}/&/]+}%&{});#$&&s&&$^X.($'^"%]=\&(\|?{%` `+`.+=%;.#_}\&"^"-+%*).}%:##%}={~=~:.")&e&&s""`$''`"e	[reply] [d/l] [select]
Re^3: Regexp: How to match in middle but not the ends? by ikegami (Patriarch) on Jul 30, 2006 at 17:16 UTC
No, he shouldn't use "+", since he doesn't want to strip any sequence of "L". For example, your solution fails to match "LL" in "---LLLL---". My solution was lacking since I wasn't checking for an L at the start or end of the string. Fixes: `$string =~ s/-L\|L-/-/g; $string =~ s/^L//; $string =~ s/L$//;` [download] or `$string =~ s/^L\|(?<-)L\|L(?=-)\|L$//g;` [download] or `# Does a bit more than stripping, but in an inconsequential fashion. $string =~ s/^L\|-L\|L-\|L$/-/g;` [download]	[reply] [d/l] [select]
Re^4: Regexp: How to match in middle but not the ends? by Skeeve (Parson) on Jul 30, 2006 at 20:10 UTC
It's debatable: The OP said, the strings may not start or end with L. He didn't say which strings: Those, that are returned (use +) or those that are found (don't use +). I vote for the strings returned ;-) But only the OP can tell. P.S. See his (partial) Solution, He's cutting of all leading L's, so I have a good argument for my view, don't you agree? `s$$([},&%#}/&/]+}%&{});#$&&s&&$^X.($'^"%]=\&(\|?{%` `+`.+=%;.#_}\&"^"-+%*).}%:##%}={~=~:.")&e&&s""`$''`"e	[reply] [d/l] [select]
Re^2: Regexp: How to match in middle but not the ends? by Hofmator (Curate) on Jul 31, 2006 at 11:08 UTC
`print join ', ', $string =~ /([CSH][CSHL]+[CSH])/g;` matches at least 3 characters and thus should be `print join ', ', $string =~ /([CSH][CSHL]*[CSH])/g;` (as you mention somewhere else in this thread). -- Hofmator	[reply] [d/l] [select]