On 1/25/19 11:32 AM, Kai Peter wrote: > > Really interesting _how_ people think. Find the error: >
You're not even trying: $ echo 0.0.0.0 | sed 's/\.0/\./g' | sed 's/^0//g' | \ sed 's/\.0/\./g' | sed 's/\.\./.0./g' | sed 's/^0//g' .0.. It's trivial to enumerate all "valid" (that is, without leading zeros) IP addresses. The most basic test that any regex should pass is that it should do nothing on those examples.