Can't increase Mac OSX bash shell history length I set ~/.bash_profile some time ago to have more than 500 lines length but seems system can't catch this. 

Do you know why?

&gt; nano -w ~/.bash_profile
export CLICOLOR=1
export LSCOLORS=GxFxCxDxBxegedabagaced
HISTFILESIZE=10000000

&gt; history | wc -l
     500
You also need to set HISTSIZE=10000000.

HISTFILESIZE determines the number of lines to keep in the history file while HISTSIZE determines the number of lines to keep in memory.  Both default to 500

Execute echo $HISTFILESIZE $HISTSIZE before you make the change and then again after.  You should see 10000000 500 first then 10000000 10000000 after.