Re: [9fans] awk help; not plan9 matter

[roger peppe]

another approach, build up a regexp and use that:

fn changefield {
        n = $1
        repl = $2
        s=')([^         ]+)(.*)'
        for(i in `{seq 1 `{echo $n 1 -p | dc}}){
                s='[^   ]+[     ]+'^$s
        }
        s='('^$s
        sed 's/'^$s^'/\1'^$repl^'\3/'
}

(N.B. if the replacement string
might contain / or \, those characters would need
quoting)