You can also use tr for such removals, should be faster.

See also: perlretut

Use Benchmark when in doubt. YMMV. The first thing I would do for speeding that up is adding a + after the character class, but below proves I'm wrong.

$ cat test.pl
#!/pro/bin/perl

use strict;
use warnings;

use Benchmark "cmpthese";

my $string  = pack "A*" => map { chr (32 + int rand 95) } 0..1280;

cmpthese (-1, {
    subsingle   => '(my $s = $string) =~ s/[^a-zA-Z0-9 _-]//g',
    subplus     => '(my $s = $string) =~ s/[^a-zA-Z0-9 _-]+//g',
    tran        => '(my $s = $string) =~ tr/a-zA-Z0-9 _-//cd',
    });
$ perl5.8.8 test.pl
               Rate      tran   subplus subsingle
tran      5938537/s        --       -1%       -2%
subplus   5983722/s        1%        --       -1%
subsingle 6052802/s        2%        1%        --
$ perl5.10.1 test.pl
               Rate      tran   subplus subsingle
tran      5242880/s        --       -2%       -5%
subplus   5344683/s        2%        --       -3%
subsingle 5531478/s        6%        3%        --
$ perl5.12.3 test.pl
               Rate      tran   subplus subsingle
tran      5044286/s        --       -2%       -4%
subplus   5144881/s        2%        --       -2%
subsingle 5242880/s        4%        2%        --
$ perl5.14.1 test.pl
               Rate      tran   subplus subsingle
tran      5144881/s        --       -9%      -10%
subplus   5663605/s       10%        --       -1%
subsingle 5716536/s       11%        1%        --
$
[download]


Enjoy, Have FUN! H.Merijn

'use Benchmark' advice usually makes me shudder. As so often is the case, you have a tiny mistake in your code and so are benchmarking nearly identical do-nothing chunks of code.

#!/usr/bin/perl -w

use strict;

use Benchmark "cmpthese";

my $string  = pack "A*" => map { chr (32 + int rand 95) } 0..1024000;

cmpthese( -1, {
    subsingle   => '(my $s = $string) =~ s/[^a-zA-Z0-9 _-]//g',
    subplus     => '(my $s = $string) =~ s/[^a-zA-Z0-9 _-]+//g',
    tran        => '(my $s = $string) =~ tr/a-zA-Z0-9 _-//cd',
} );
warn "Second version\n";
cmpthese( -1, {
    subsingle   => sub { (my $s = $string) =~ s/[^a-zA-Z0-9 _-]//g },
    subplus     => sub { (my $s = $string) =~ s/[^a-zA-Z0-9 _-]+//g },
    tran        => sub { (my $s = $string) =~ tr/a-zA-Z0-9 _-//cd },
} );
__END__
Use of uninitialized value in transliteration (tr///) at (eval 14) lin
+e 1.
[about a million warnings]
Use of uninitialized value in transliteration (tr///) at (eval 140) li
+ne 1.
Second version
              Rate   subplus subsingle      tran
subplus   114916/s        --       -4%      -14%
subsingle 119259/s        4%        --      -10%
tran      133187/s       16%       12%        --
               Rate   subplus subsingle      tran
subplus   2171607/s        --       -4%      -70%
subsingle 2256550/s        4%        --      -68%
tran      7143583/s      229%      217%        --
[download]

The most important take-away from this should be that, even with Benchmark.pm going to extraordinary efforts to try to subtract out the "overhead", I had to resort to ridiculously long strings before it could really tell a difference between the three choices.

So you are not going to notice a difference.

When something takes 0.0000004 seconds for an extraordinarily long string, making it take only 0.0000001 seconds rarely actually matters (especially when you don't have extraordinarily long strings), especially since, outside of Benchmark.pm's imagined view of things, the overhead of actually getting to the point of running the regex or tr/// is going to swamp that 0.0000001-second fiction.

- tye        

All accents should be removed too

You mean that you want the accented characters removed? Or just the accents from the accented characters?

If the latter, you'll need to explain the source of the strings and probably get into messing with encodings as a regex won't (easily) do that.

Text::Unidecode can remove the accents, but leave the basic character in place. First run the undidecode unidecode function on your string and then apply the regex.

Update: fixed a typo. Thanks BrowserUK.

CountZero

A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

Will it work on Extended ANSI codepages? Or only Unicoded input?

Plus, it might be better to tell the OP rather than me since he's the one looking for it.

(ps. Is undidecoding, extracting that which makes Diddy men what they are, from their DNA? :)

---

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

The start of some sanity?

CountZero, thanks a lot! you made my day :-)