Re: Counting SubStrings, Style Question

lanx@nc10-ubuntu:~$ perl -e '
$sub = "xxx";
$par = "xxx xxx xxx";
$count = () = $par =~ /$sub/g;
$count == 0 
   ? print "none" 
   : $count == 1 
       ? print "unique" 
       : print "duplicates";
'
duplicates
[download]

HTH! :)

Cheers Rolf

UPDATE: beautified code ;)

see here how to avoid the ternary cascade.

Comment on Re: Counting SubStrings, Style Question Download Code

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Re^2: Counting SubStrings, Style Question by AnomalousMonk (Archbishop) on Mar 20, 2010 at 20:58 UTC
Although the OPed question does not seem to be concerned with overlapping occurrences, they can also be handled with `m{pattern}g`. If the sub-string may contain regex metacharacters, it is also wise to meta-quote. >perl -wMstrict -le "my $substring = 'xxx'; for my $string (@ARGV) { my $non_overlap =()= $string =~ m{ \Q$substring\E }xmsg; my $overlap =()= $string =~ m{ (?= (\Q$substring\E)) }xmsg; print qq{$non_overlap non-overlapping $substring in $string}; print qq{$overlap overlapping $substring in $string}; } " x xx xxx xxxx xxxxx xxxxxx 0 non-overlapping xxx in x 0 overlapping xxx in x 0 non-overlapping xxx in xx 0 overlapping xxx in xx 1 non-overlapping xxx in xxx 1 overlapping xxx in xxx 1 non-overlapping xxx in xxxx 2 overlapping xxx in xxxx 1 non-overlapping xxx in xxxxx 3 overlapping xxx in xxxxx 2 non-overlapping xxx in xxxxxx 4 overlapping xxx in xxxxxx [download] Update: The capturing group in `m{ (?= (\Q$substring\E)) }xmsg` is needed only if there is a concern with what matched rather than only with how many matched as in the OPed question.	[reply] [d/l] [select]
Re^3: Counting SubStrings, Style Question by LanX (Saint) on Mar 20, 2010 at 21:14 UTC
> If the sub-string may contain regex metacharacters, it is also wise to meta-quote. the same when using split. Cheers Rolf	[reply]