Redhat or Fedora Core:

/var/log/secure

# Mandrake, FreeBSD or OpenBSD:

/var/log/auth.log

# SuSE:

/var/log/messages

# Mac OS X (v10.4 or greater):

/private/var/log/asl.log

# Mac OS X (v10.3 or earlier):

/private/var/log/system.log

# Debian:

/var/log/auth.log