# logger -sp <средство>.<уровень> -t <имя_процесса> "текст"

Пример 2:
mycomp# logger -p cron.debug this is test message 222222
  после этой команды в файлах /var/log/cron и /var/log/debug.log появится запись:
Feb  8 15:07:02 msinhome root: this is test message 222222

Пример 3:
mycomp# logger -ps debug this is test message 333333
  после этой команды в файлах /var/log/debug.log появится запись:
Feb  8 15:15:52 msinhome root: this is test message 333333, а также сообщение выведется на
консоль:
root: this is test message 3333333

Примеры тестировались на FreeBSD 6.3 с /etc/syslog.conf, настроенным по умолчанию.
Вот его содержимое:
# $FreeBSD: src/etc/syslog.conf,v 1.28 2005/03/12 12:31:16 glebius Exp $
#
#       Spaces ARE valid field separators in this file. However,
#       other *nix-like systems still insist on using tabs as field
#       separators. If you are sharing this file between systems, you
#       may want to use only tabs as field separators here.
#       Consult the syslog.conf(5) manpage.
*.err;kern.warning;auth.notice;mail.crit                /dev/console
*.notice;authpriv.none;kern.debug;lpr.info;mail.crit;news.err   /var/log/messages
security.*                                      /var/log/security
auth.info;authpriv.info                         /var/log/auth.log
mail.info                                       /var/log/maillog
lpr.info                                        /var/log/lpd-errs
ftp.info                                        /var/log/xferlog
cron.*                                          /var/log/cron
*.=debug                                        /var/log/debug.log
*.emerg                                         *
# uncomment this to log all writes to /dev/console to /var/log/console.log
#console.info                                   /var/log/console.log ]
# uncomment this to enable logging of all log messages to /var/log/all.log
# touch /var/log/all.log and chmod it to mode 600 before it will work
#*.*                                            /var/log/all.log
# uncomment this to enable logging to a remote loghost named loghost
#*.*                                            @loghost
# uncomment these if you're running inn
# news.crit                                     /var/log/news/news.crit
# news.err                                      /var/log/news/news.err
# news.notice                                   /var/log/news/news.notice
!startslip
*.*                                             /var/log/slip.log
!ppp
*.*                                             /var/log/ppp.log
!mpd
*.*                                             /var/log/mpd.log