history-backup

#!/usr/bin/env sh
# by http://lukas.zapletalovi.com/2013/03/never-lost-your-bash-history-again.html
# This script creates monthly backups of the bash history file. Make sure you have
# HISTSIZE set to large number (more than number of commands you can type in every
# month). It keeps last 200 commands when it "rotates" history file every month.
# Typical usage in a bash profile:
#    #!/bin/sh
# This script creates monthly backups of the bash history file. Make sure you have
# HISTSIZE set to large number (more than number of commands you can type in every
# month). It keeps last 200 commands when it "rotates" history file every month.
# Typical usage in a bash profile:
#
# HISTSIZE=90000
# source ~/bin/history-backup
#
# And to search whole history use:
# grep xyz -h --color ~/.bash_history.*
#

KEEP=2000
HISTORY_FILE=${HISTFILE:-${HOME}/.bash_history}
BACKUP=${HOME}/bash_history_backup/$(basename ${HISTORY_FILE}.$(date +%Y-%U))
BASE_DIR=~/

cd $BASE_DIR
mkdir -p bash_history_backup
if [ -s "${HISTORY_FILE}" -a "${HISTORY_FILE}" -nt "${BACKUP}" ]; then
  # history file is newer then backup
  if [[ -f ${BACKUP} ]]; then
    # there is already a backup
    cp -f ${HISTORY_FILE} ${BACKUP}
  else
    # create new backup, leave last few commands and reinitialize
    mv -f ${HISTORY_FILE} ${BACKUP}
    tail -n${KEEP} ${BACKUP} > ${HISTORY_FILE}
    history -r
    echo "Created new history backup. Kept last ${KEEP} commands in history"
  fi
fi