*! readtok--break a string variable into a set of token variables
*! version 1.0     Sean Becketti     January 1996		(STB-29: ip12)
program define readtok
version 4.0
quietly {
        local varlist "req ex max(1)"
	local options "Field(str) Prefix(str)"
	parse "`*'"
	if "`prefix'"=="" { local prefix "_v" }
        confirm string variable `varlist'
        local type : type `varlist'
	local i 0
	local n 0
	while `i' < _N {
		local i = `i' + 1
		local s = `varlist'[`i']
		xparse , parse(" `field'") string("`s'")
		local toks "$S_1"
		local jn : word count `toks'
		local j = 0
		parse "$S_1", parse(" ")
		while `j'<`jn' {
			local j = `j' + 1
			local t : word `j' of `toks'
			if `j'>`n' { 
				gen `type' `prefix'`j' = "" 
                                local newvars "`newvars' `prefix'`j'"
				local n = `j'
			}
			replace `prefix'`j' = "`t'" in `i'
		}
	}
	compress `newvars'
}
end