I ran into a similar situation at work today actually, however, I wasn't trying to do a mathimatical situation. Since I'm bored, I'll share. What I was trying to do is load a file into memory, and then perform a subsistuion, similar to $line =~ s/\n//g; , and then I was going to perform additional string subsitutions on the line. This didn't work and resulted in a "illegal division by zero" error, so I needed a different work around. I thought of subsituting a different character for \n, but that character could exist in the file, so I backed off from that approach. I never really did find out a good way to do it, so instead I made a seperate regular expression which would catch the cases where a \n was embeded in the the other regular expression I wanted to extract from the file. I think this is the more elegent and robust solution, since I later found additional special cases that I wasn't taken into effect...