I need to regain regular expression search pattern while using less command. Is there any way to do that?. Once I start searching the expression disappears. 
regain regular expression search pattern while using less command
less
When searching in less, matches are highlighted, then you can use n (or N) to search for the next (resp. previous) pattern, and if typing / (to initiate a new search) but using the up/down arrow-keys you can get (inspect and modify) the previous entered regular expression.