Probably slower than what you're using, but easier to understand (I hope):

for(my $str = 'vaction.msg'; $str; $str = substr($str, 1, length($str)
+)) {
    $replace_on =~ s/$str//;
}
[download]

Ahh, the rarely seen (around here, anyway) three-element form of for. I've tested this loop and it produces the strings correctly. I don't know if this exactly matches your needs, but you should be able to modify it easily enough.

Update: Forgot that you need to escape the '.' before it gets put in a regex, which complicates things a bit.

----
I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident.
-- Schemer

Note: All code is untested, unless otherwise stated

Forgot that you need to escape the '.' before it gets put in a regex, which complicates things a bit.

Not by that much. All you need to add, is '\Q':

$replace_on =~ s/\Q$str//;
[download]

I won't comment on the actual value of your idea, though. :)

#!/usr/bin/perl

use strict;

my $str;
my $tomatch = 'foobar the vacation.msg is here';
my @permute = map { 
   $str; $str = $_ . $str; 
} ( reverse( split(//, 'vacation') ) );

$regex = '(\.?(?:' . join('|', reverse(@permute)) . ')\.msg)';

print "$regex\n";

print "Match: $1\n" if ($regex =~ m/$tomatch/ );
[download]

Assuming that I haven't screwed up again, which is by no means guarenteed, your regex doesn't quite catch all the cases.

Input  cation.msgThe quick brown fox jumps over the lazy dog

Output  caThe quick brown fox jumps over the lazy dog

However, that could be corrected. And the sad truth is that your version actually runs a tad faster than my (second) attempt, and also tye's offering, though the difference is marginal, and may fade once you correct the error.

The only saving grace is that mine is shorter and prettier, but then tye's is even shorter and prettier than mine, and runs a tad quicker to boot.

I'm taking a vacation as of now, from PM at least. It would be nice to take a real one, but that's not an option. I might be back someday.

This seems to do what you want, if I understand you correctly.

$line =~ s[v?a?c?a?t?i?o?n\.msg][];

Update: Right idea, wrong execution. See 271190 below :( I think this is better.

$line =~ s[(?:(?:(?:(?:(?:(?:v?a)?c)?a)?t)?i)?o)?n.msg][];

Test code

That also removes cat.msg, vain.msg, etc. Closer to the original intent (as best as I can tell) would be:

$line =~ s[v?(a?(c?(a?(t?(i?(o?(n?(\.?(m?(­s?g))))))))))][];
[download]

                - tye

Your right. It does need brackets. I had another go similar in vein to yours, though I bracketed the other way. Both seem to work, with the same caveat that in the partial insertion is preceded by one or more characters that match the missing part, they get removed also, but without some delimeter, this will always be the case.

Any thought about which bracketing causes the least amount of work?

---

Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong." -Richard Buckminster Fuller

oops!

last two lines of output

The quick brown fox jumps oer the lazy dog
The quick brown fox jumps over the lazy dog
[download]

Where did that 'v' go?

---

Your right. It was flawed. Another attempt.

#! perl -slw
use strict;

# Set up some test data.
my $text = 'The quick brown fox jumps over the lazy dog';
my @tests = map{
    my $t = $text;
    substr($t, rand( length $text ), 0 ) = $_;
    $t;
} map{
    substr 'vacation.msg', $_
} 0 ..6;

print "Before\n";
print for @tests;

#
s[(?:(?:(?:(?:(?:(?:v?a)?c)?a)?t)?i)?o)?n.msg][] for @tests;

print "\nAfter\n";
print for @tests;

__END__
P:\>junk
Before

The quick brown fox jumps ovvacation.msger the lazy dog
The quick brown fox jumps oacation.msgver the lazy dog
The quick brocation.msgwn fox jumps over the lazy dog
The quick brown fox jumpsation.msg over the lazy dog
The quick brown fox jumps over the lation.msgzy dog
Tion.msghe quick brown fox jumps over the lazy dog
The quick brown fox jumps over the lazy on.msgdog

After

The quick brown fox jumps over the lazy dog
The quick brown fox jumps over the lazy dog
The quick brown fox jumps over the lazy dog
The quick brown fox jumps over the lazy dog
The quick brown fox jumps over the lzy dog
The quick brown fox jumps over the lazy dog
The quick brown fox jumps over the lazy dog
[download]

This time, the apparent error is explainable.

Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong." -Richard Buckminster Fuller

Rather than immediately jumping into churning out code, we should perhaps ask why one should also look at "any pieces of its name"?

Is it perhaps because this string might be split over two lines?

If that is the case, than I can imagine that simpler solutions are available.

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law