irc-sanitizer.py

#!/usr/bin/env python
import re
import sys

# 00:00:00 < user> optional_prefix: TEXT TO KEEP
content = re.compile('^[0-9]{2}(:[0-9]{2})+ <[^>]+> ([^\s]+:\s)?(.*)$')

for line in sys.stdin:
    result = content.search(line)
    try:
        line = result.group(3).strip()
    except AttributeError:
        continue
    if line:
        print ' '.join(line.split()).strip()