An alternative using tr (see Transliteration in Quote and Quote like Operators) to count the number of 'r's.

knoppix@Microknoppix:~$ perl -E '
> open my $fh, q{<}, \ <<EOD or die $!;
> 0  a b h
> 1  - r z
> 3  u - u
> 4  r x r
> 5  r t r
> 6  r r r
> 7  r r r
> 8  r r r
> EOD
> 
> while ( <$fh> )   
> {
>     my( $seq, @cols ) = split;
>     print if tr{r}{} == scalar @cols;
> }'
6  r r r
7  r r r
8  r r r
knoppix@Microknoppix:~$

[download]

Cheers,

JohnGG

In reply to Re: Count similar characters in a row by johngg
in thread Count similar characters in a row by $new_guy

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