Odd behavior with split in perl when result includes empty strings

Question

This is my perl 5.16 code

while(<>) {
  chomp;
  @data = split /a/, $_;
  print(join("b",@data),"\n");
}

If I input a file with this in it:

paaaa
paaaaq

I get

p
pbbbbq

But I was expecting

pbbbb
pbbbbq

Why am I wrong to expect the latter behavior?

Answer 1

It is documented that trailing empties are removed unless you specify a third, non-zero argument.

If LIMIT is omitted (or, equivalently, zero), then it is usually treated as if it were instead negative but with the exception that trailing empty fields are stripped (empty leading fields are always preserved)

You want

split /a/, $_, -1;