useragent_log
This directive causes Squid to create a log file of User-Agent strings. The file contains three
fields: client identifier, timestamp, and user-agent string. The
client identifier is an IP address, unless you enable the
log_fqdn directive, in which case it is a
hostname if one is available. Squid writes an entry for every HTTP
request that has a User-Agent
header. Unlike access.log,
entries are written to this file when the request is received.