5. Python 3, 3664 bytes
.0e0 or012
import sys
print(len(inputsys . stdin . read()) ** 0.5%1==05 % 1 == 0)
Try it online! [Try it online!][TIO-jezj15lk] [TIO-jezj15lk]: https://tio.run/##K6gsycjPM/7/X8/A0IgrM7cgv6hEobiymKugKDOvRCMnNU8DyFPQUyguScnMA9JFqYkpGpqaClpaCgZ6pgqqCoYKtrYKBpqUmwAA "Python 3 – Try It Online"
Checks if the length of the input is a perfect square.
This had been updated by the time 18 answers were present to support multiline input.
The update does not hurt the chain.
Satisfies:
- starts with a
.
- contains an
e
- has an even length
- has a perfect square length