Jika pengguna Anda menggunakan bash, Anda dapat menggunakan skrip /etc/bash.bash_logout untuk menyimpan salinan sejarah tambahan dalam format cap waktu.
Sebagai contoh, saya menulis yang berikut ini untuk memberikan jejak audit tentang siapa yang melakukan apa dan kapan (pada server dengan beberapa pengguna sudo), dan juga untuk melestarikan sejarah seandainya mesin tersebut dipecah menjadi:
#! /bin/bash
# /etc/bash.bash_logout
#
# Time-stamped bash history logging
# by Craig Sanders <cas@taz.net.au> 2008
#
# This script is public domain. Do whatever you want with it.
exec >& /dev/null
# LOGDIR must already exist and must be mode 1777 (same as /tmp)
# put it somewhere easily overlooked by script-kiddies. /var/log
# is a bad location because slightly-brighter-than-average SK's will
# often 'rm -rf /var/log' to cover their tracks.
LOGDIR='/var/tmp/.history'
[ -d "$LOGDIR" ] || exit 0
# Get current user name and who they logged in as.
CNAME=$(id -u -n)
LNAME=$(who am i | awk '{print $1}')
NAME="$LNAME--$CNAME"
# Get the TTY
TTY=$(tty)
# get the hostname and ip they logged in from
# short (non-fqdn) hostname:
RHOST_NAME=$(who -m | awk '{print $5}' | sed -r -e 's/[()]|\..*//g')
# or full hostname:
#RHOST_NAME=$(who -m | awk '{print $5}' | sed -r -e 's/[()]//g')
# if no RHOST_NAME, then login was on the console.
echo "$RHOST_NAME" | grep -q '[:/]' && RHOST_NAME="console"
# get the IP address
RHOST_IP=$(who -m --ips | awk '{print $5}')
echo "$RHOST_IP" | grep -q '[:/]' && RHOST_IP="console"
RHOST=$(echo "$RHOST_NAME--$RHOST_IP")
WHERE="$RHOST--$TTY"
WHERE=$(echo "$WHERE" | sed -e 's/\//-/g' -e 's/^-//')
# Filenames will be of the form:
# $LOGDIR/cas--root--localhost--127.0.0.1---dev-pts-1
# Ugly, but useful/informative. This example shows I logged in as cas
# from localhost, sudo-ed to root, and my tty was /dev/pts/1
HISTLOG="$LOGDIR/$NAME--$WHERE"
# Optionally rotate HISTLOG on each logout, otherwise new history
# sessions just get appended.
#[ -e "$HISTLOG" ] && savelog -l -c 21 -q $HISTLOG > /dev/null 2>&1
# Log some easily parseable info as a prelude, including the current
# history settings (an unusual HISTFILE or zero HISTSIZE setting is
# suspicious and worthy of investigation)
cat <<__EOF__ >> "$HISTLOG"
### TIME ### $(date +'%a,%Y-%m-%d,%H:%M:%S')
### FROM ### $RHOST_NAME,$RHOST_IP,$TTY
### USER ### $LNAME,$CNAME
### WHOM ### $(who -m)
### HIST ### $HISTFILE,$HISTSIZE
__EOF__
# Setting HISTTIMEFORMAT seems to be buggy. bash man page says it uses
# strftime, but all it seems to care about is whether it's set or not -
# 'history -a' always uses seconds since epoch, regardless of what it is
# set to.
HISTTIMEFORMAT="%s"
history -a "$HISTLOG"
# Now write history as normal (this seems buggy too. bash used to always
# write $HISTFILE anyway, but now it won't do it if you've already run
# 'history -a')
unset HISTTIMEFORMAT
history -w