$str =~ s/’/'/;
[download]

Not silly at all and it works for me too.
It's just that I can't see the damn thing in my editor :-(

If you're trying to remove all \x{92} characters with a regexp, be sure to use the /g modifier. However, if that's your intent, use the transliteration operator instead; that's what it's designed for, and it's more efficient at its job:

$str =~ tr/\x{092}/'/d;
[download]

That ought to do the trick.

In the first case you would be biten by the fact that the \xNN form works only when you have two hex chars, not three as in 092. So, the fact that you always get the same output is the real puzzle here.

#!/usr/bin/perl
use strict;
use warnings;
 
my $str = q|cat’s|;
printit($str, 'original');
 
(my $str1 = $str) =~ s/\x092/'/;
printit($str1, 'hex only two nybbles');
 
(my $str2 = $str) =~ s/\x92/'/;
printit($str2, 'seems good here');
 
(my $str3 = $str) =~ s/\x{092}/'/;
printit($str3, 'seems good here');
 
(my $str4 = $str) =~ tr/\x{092}/'/d;
printit($str4, 'seems good here');
 
sub printit {
        my ($v, $msg) = @_;
        my $h = unpack "H*", $v;
        $h =~ s/(..)/0x$1 /g;
        print "$h\t$v\t$msg\n";
}

__END__

0x63 0x61 0x74 0x92 0x73        cat?s   original
0x63 0x61 0x74 0x92 0x73        cat?s   hex only two nybbles
0x63 0x61 0x74 0x27 0x73        cat's   seems good here
0x63 0x61 0x74 0x27 0x73        cat's   seems good here
0x63 0x61 0x74 0x27 0x73        cat's   seems good here
[download]

Many thanks for your efforts

I added a test suggested by kwaping above.

#!/usr/bin/perl

use strict;
use warnings;
 
my $str = q|cat’s|;
printit($str, 'original');
 
(my $str1 = $str) =~ s/\x092/'/;
printit($str1, 'hex only two nybbles');
 
(my $str2 = $str) =~ s/\x92/'/;
printit($str2, 'seems good here');
 
(my $str3 = $str) =~ s/\x{092}/'/;
printit($str3, 'seems good here');
 
(my $str4 = $str) =~ tr/\x{092}/'/d;
printit($str4, 'seems good here');

(my $str5 = $str) =~ s/’/'/;
printit($str5, 'added');
 
sub printit {
        my ($v, $msg) = @_;
        my $h = unpack "H*", $v;
        $h =~ s/(..)/0x$1 /g;
        print "$h\t$v\t$msg\n";
}

__END__

0x63 0x61 0x74 0xe2 0x80 0x99 0x73     cat’s    original
0x63 0x61 0x74 0xe2 0x80 0x99 0x73     cat’s    hex only two nybbles
0x63 0x61 0x74 0xe2 0x80 0x99 0x73     cat’s    seems good here
0x63 0x61 0x74 0xe2 0x80 0x99 0x73     cat’s    seems good here
0x63 0x61 0x74 0xe2 0x80 0x99 0x73     cat’s    seems good here
0x63 0x61 0x74 0x27 0x73     cat's    added
[download]

You're saving your Perl script as a UTF-8 file but not telling Perl that it is supposed to be reading the script as such. (I bet)

- tye