I could only duplicate your results with adding /g to the first regex. I have no frickin' clue how the substitution works. Incidentally, the following is a no-op:

for ($target =~ /is/g) {
    s//are/;
}
[download]

But if I take of the /g switch:

for ($target =~ /is/) {
    s//are/;
}
[download]

I get the following error message:

Modification of a read-only value attempted at eval.pl line 6.
[download]

This is beginning to look like a bug to me.

Cheers,
Ovid

Join the Perlmonks Setiathome Group or just click on the the link and check out our stats.