# perl -v

This is perl, v5.6.1 built for sun4-solaris

...

# perl -e 'use Sys::Syslog; syslog "auth.info", "from perl"'
syslog: invalid level/facility: auth at -e line 1

# perl -e 'use Sys::Syslog; sub Sys::Syslog::LOG_AUTH () { 4<<3 }; syslog "auth.info", "from perl"'

# tail -1 /var/log/auth
Dec 21 16:30:08 host.sub.dom username: from perl