When working on Linux it is often very helpful to review the commands that you have entered. For example, you may want to paste some of the commands into a script or may want to recreate the steps to solve the problem you were working on.
Here is how I do it:
## Modify History for Current Session
# Add Timestamp to .bash_history
HISTTIMEFORMAT="%d/%m/%y %T "
# Write Current History to .bash_history
history -a
# Update .bash_history with every command
export PROMPT_COMMAND='history -a'
## Add to .bash_profile to make changes permanent
echo 'export HISTTIMEFORMAT="%d/%m/%y %T "' >> $HOME/.bashrc
echo "export PROMPT_COMMAND='history -a'" >> $HOME/.bashrc
## Save the last 10,000 lines to disk and keep 5000 lines in memory
cat $HOME/.bashrc | sed 's/#\?\(HISTSIZE\s*=\s*\).*$/\15000/' | \
sed 's/#\?\(HISTFILESIZE\s*=\s*\).*$/\110000/' > temp.txt
mv -f temp.txt $HOME/.bashrc
source ~/.bashrc
NOTE: if you want to display the recent history without timestamps, just use fc -ln
