If you're using bash 4.3 (released 2014) or higher you could convert this from using an "undocumented feature" to use the documented feature that does the same.

If you're using bash 4.3 (released 2014) or higher you could convert this from using an "undocumented feature" to use the documented feature that does the same... > "Numeric values less than zero result in every command being saved on the history list (there is no limit)." export HISTFILESIZE=-1 export HISTSIZE=-1