RosettaCodeData/Task/Prime-decomposition/AWK/prime-decomposition.awk

# Usage:  awk -f primefac.awk
function pfac(n,    r, f){
    r = ""; f = 2
    while (f <= n) {
        while(!(n % f)) {
            n = n / f
            r = r " " f
        }
        f = f + 2 - (f == 2)
    }
    return r
}

# For each line of input, print the prime factors.
{ print pfac($1) }