program demo_regfree use M_regex, only: regex_type, regcomp, regexec, regmatch, regfree, regerror implicit none integer :: istat type(regex_type) :: regex character(len=:),allocatable :: expression expression= "([0-9\.\-\*\/]+)+" call regcomp(regex,expression,'x') if (istat/=0) then stop 'Regex runtime error: regcomp failed.' endif call regfree(regex) end program demo_regfree